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The abundance and diversity of desert invertebrates in Abu Dhabi and their roie in the diet

of the houbara bustard Chlamydotis undulatamacqueeni

Barbara Jane Tigar

Doctor of Philosophy (PhD) University of London 1998

BIBL [LOUDON]

UNIV.

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A b str a c t

Invertebrate abundance and diversity were monitored for two years at five sites in

Abu Dhabi, and houbara bustard faecal and gizzard contents were examined to

establish the role of invertebrates in the diet.

Literature on houbara diet was used to calculate a relative citation index for known

foods. Invertebrates, particularly Coleoptera, Orthoptera and Formicidae, scored

highest; Tenebrionidae were especially important. All houbara subspecies ate plants

from the families: Gramineae, Leguminosae, Cruciferae, Compositae and

Solanaceae. African and Arabian houbara also ate Zygophyllaceae and

Chenopodiaceae. Canary Island birds may have a narrower diet than mainland

houbara.

Overnight pitfall and light-traps captured 143,397 invertebrates, including 196 new

records and ten new species. Pitfalls frequently contained: Formicidae (75.4%),

Thysanura (12%), Coleoptera (8.4%), Araneae (1.5%) and Scorpiones (1.1%). Light

traps had high catches of Lepidoptera (56.4%) and Coleoptera (19.1%); Coleoptera

contributed the highest biomass (42.6%). Fewer invertebrates were caught in winter

than in summer, and catches were positively correlated with temperature. There

were significant differences in community composition between sites and

substrates. Isoptera, Tettigoniidae and Carabidae were rarely captured inland, but

more taxa occurred near the coast. Pitfalls captured higher numbers of more

diverse predaceous arthropods at new moons than at full moons, suggesting

differences in invertebrate predation risk or visual awareness of traps.

Similar food remains were recovered from houbara faeces and gizzards. Trials

established a calibration for the recovery of prey remains in faeces. Formicidae

were the most frequently consumed prey, but Tenebrionidae formed the highest

biomass. Plants made a low but frequent contribution to the diet. Estimated Active

Metabolic Rate suggested that invertebrates contributed 89-94.6% to houbara

energy needs, and the frequency of invertebrates in faeces showed good rank

agreement with pitfall catches.

Desert invertebrates showed spatial and temporal variation and over-wintering

houbara appeared to be non-selective, consuming mainly locally available, ground- dwelling invertebrates.

T a b le o f C o n te n ts

PageAbstract 2Table of contents 3List of tables 7List of figures 10List of plates 11List of appendices 12Acknowledgements 13

C h a p te r 1 - General introduction 15

Synopsis of Chapter 1 151.1 Identifying the problem: rationale behind the research 161.2 Abu Dhabi and the United Arab Emirates 17

Introduction 17Geology 19Climate 20Ecology 21Invertebrates 22

1.3 Introduction to the bustards - family Otididae 261.4 The houbara bustard 27

Subspecies and their ranges 27Houbara habitat 29Ecology of Chlamydotis undulata macqueeni 29Conservation and status of the houbara 30

C h a p t e r 2 -The diet of the houbara bustard - a review 32

Synopsis of Chapter 2 322.1 Introduction 332.2 The review of the diet 33

2.2.1 The Canary Island houbara: Chlamydotis undulata fuertaventurae 33General descriptions of the diet 33Animal foods 45Plant foods 45Studies based on faecal analysis 45Feeding behaviour of C.u.fuertaventurae 47

2.2.2 The North African houbara: Chlamydotis undulata undulata 47General descriptions of the diet 47Gizzard content analysis 48

2.2.3 MacQueen’s bustard: Chlamydotis undulata macqueeni 49Middle Eastern population 49

Studies based on faecal analysis 50Pakistani and Indian populations 50

General description of the diet 50Plant foods 51Studies based on gizzard contents 52

Central Asian population 53General descriptions of the diet 53Plant foods 54Studies based on gizzard contents 54Studies based on faecal analysis 54

C h a p te r 2 -The diet of the houbara bustard - a review (continued)

2.2 The review of the diet (continued)2.2.4 Vagrant houbara 562.2.5 Gizzard stones 572.2.6 The diet of semi-captive houbara 572.2.7 Diets for captive houbara 57

2.3 Discussion 602.3.1 Relative merits of techniques used to study the diet 602.3.2 A comparison of the diet of the three houbara subspecies 61

Citation indices for plant foods 64Citation indices for animal foods 65

2.3.3 Seasonal trends in the houbara's diet 66Seasonal consumption of plant foods 66Seasonal consumption of animal foods 67

2.3.4 Implications for the management of habitat and captive birds 682.4 Conclusion 69

C h a p te r 3 - Pilot studies for monitoring desert invertebrates 70

Synopsis of Chapter 3 703.1 General Introduction 713.2 Pitfall trapping 71

3.2.1 Introduction to pitfall trials 713.2.2 Methods 72

The trapping-time trial 72The transect length trial 72

3.2.3 Results 73The trapping-time trial 73The transect length trial 74Species-effort curve 76

3.2.4 Discussion 783.3 The use of refuge boards 80

3.3.1 Introduction 803.3.2 Methods 803.3.3 Results 803.3.4 Discussion 81

3.4 Sweep-netting and beating trays 813.4.1 Introduction and methods 813.4.2 Results 823.4.3 Discussion 83

3.5 Walking transects for Orthoptera 833.5.1 Introduction and methods 833.5.2 Results 833.5.3 Discussion 84

3.6 Flight interception traps 843.6.1 Introduction and methods 843.6.2 Results 843.6.3 Discussion 84

3.7 The use of light traps for the capture of nocturnal insects. 863.8 General discussion and recommendations for trapping methods 86

C h a p te r 4 - The diversity and abundance of invertebrates in Abu Dhabi's 88 deserts

Synopsis of Chapter 4 884.1 Patterns of abundance and diversity of ground dwelling arthropods 89

4.1.1 Introduction 894.1.2 Methods 90

Trapping sites 90Pitfall trapping 90Climatic data 93Data analysis 93

4.1.3 Results 95The arthropod community 95Temporal variation in total catch 95Spatial variation in total catch 98Spatial variation in taxonomic diversity 100

4.1.4 Discussion 102Community composition 102Temporal variation 104Spatial-temporal variation 104Spatial variation 105Conclusion 106

4.2 Does the phase of the moon influence invertebrate trap catch? 1074.2.1 Introduction 1074.2.2 Methods 107

Invertebrate trapping 107Data analysis 107

4.2.3 Results 109The arthropod community 109Variation in arthropod abundance 111Variation in taxonomic diversity 111Species composition according to the phase of the moon and 113substrate

4.2.4 Discussion 1164.3 Patterns of available biomass and diversity of flying invertebrates 119


The light trap 119Data analysis 119

4.3.3 Results 120Variations in the number of flying insects 121Variations in insect diversity between sites 124

4.3.4 Discussion 1264.4 General discussion on Abu Dhabi’s invertebrates 129

The invertebrate community 129Temporal patterns 130Spatial patterns 131Implications for biodiversity studies 131

C h a p te r 5 - The diet of the houbara bustard in Abu Dhabi 133

Synopsis of Chapter 5 1335.1 Introduction 1345.2 Quantifying the diet via faecal analysis 134


Calibration experiments with animal prey 135Faecal sample collection from wild birds 137Faecal analysis 137Dietary calculations 138

5.2.3 Results 139Calibration experiments with animal foods 139Faecal analysis 142

5.2.4 Discussion 148The relative merits of different dietary calculations and indices 148Identification of key fragments 151

5.3 Analysis of houbara gizzards from Abu Dhabi 1535.3.1 Introduction 1535.3.2 Methods 1535.3.3 Results 1535.3.4 Discussion 155

5.4 General discussion of the diet 1575.4.1 Description of houbara diet in Abu Dhabi 1575.4.2 Comparison with other studies on houbara diet 1585.4.3 Measurement of the relative proportions of food types 1595.4.4 Nutritional and energetic implications 160

C h a p t e r 6 - General discussion 162

Synopsis of Chapter 6 1626.1 The ecology of arid-zone invertebrates 163

Seasonal abundance of invertebrates 163Distribution of desert invertebrates 164Diversity 165

6.2 The desert food web 1676.3 Studying houbara and other avian diets 1706.4 Houbara diet in DAE 1726.5 Conservation of houbara and wildlife in UAE 1746.6 Implications for captive breeding programmes 1756.7 Conclusions 176

Epilogue 177

R e f e r e n c e s 178

L ist o f Ta b le s

Table 2.1 List of plants eaten by the three subspecies of houbara as 34

vegetative material

Table 2.2 List of flowers, fruit and seeds eaten by the three subspecies 37

of houbara

Table 2.3 List of invertebrates eaten by the three subspecies of 40

houbara

Table 2.4 List of vertebrates eaten by the three subspecies of houbara 44

Table 2.5 Summary of hogbara gizzard contents from Central Asia 55

Table 2.6 Summary of foods eaten by vagrant houbara 56

Table 2.7 Summary of observational and other data on the diet of 58

captive and semi-captive houbara

Table 2.8 Summary of diets given to captive houbara 59

Table 2.9 The number of citations and citation index of plant foods for 62

the three houbara subspecies

Table 2.10 The number of citations and citation index of animal foods for 63

the three houbara subspecies

Table 3.1 Numbers of invertebrates and species caught by three pitfall 73

transects in place for 14, 24 and 32 hours

Table 3.2 Percentage recovery of refuge boards after 28 days in the 81

desert

Table 3.3 Number of invertebrates and taxa caught along twelve 200 m 82sweep-net transects

Table 3.4 Insects caught by a Malaise trap at Sweihan Research 85

Station

Table 4.1 Site characteristics and summary statistics for the arthropod 92

communities

Table 4.2 Composition of the 53,396 arthropods caught by pitfall- 94

trapping over two years in Abu Dhabi

Table 4.3 ANOVA F statistics for differences in the log catch of various 96

arthropod taxa at different sites, on different substrates and

for different sampling periods

L is t o f T a b le s (continued)

Table 4.4 Pearson correlations between the minimum soil temperature 98

and log catch of various arthropod groups at five desert

locations

Table 4.5 Arthropod community statistics for the five desert sites split 101by substrate

Table 4.6 Percentage composition of the sand and gravel communities 103at the five desert sites, reduced to 14 taxa for simplicity

Table 4.7 Summary of the number of arthropod taxa captured in pitfall 109

trap, grouped by phase of the moon and by substrate

Table 4.8 Total list of taxa caught in pitfall traps around full and new 110moons, shown according to biological groups

Table 4.9 F statistics for differences in log total invertebrates, 111predaceous arthropods, macroarthropod detritivores,

herbivorous insects and social insects captured in pitfall traps

at different phases of the moon, substrates and their

interaction

Table 4.10 F statistics for differences in log number of taxa for total 112invertebrates, predaceous arthropods, macroarthropod

detritivores, herbivorous insects and social insects captured

in pitfall traps at different phases of the moon, substrates and

their interaction

Table 4.11 Varimax rotated component loadings from the PCA, 114calculated from the covariance matrix

Table 4.12 Summary of total light trap catch by number and biomass 121

over two years

Table 4.13 F statistics for differences in log total invertebrates caught in 123a light trap at different sites and at different minimum air

temperatures

Table 4.14 F statistics for differences in number of orders of insects and 125the number of coleopteran families caught in a light trap at

different sites

Table 5.1 Functional groups of potential animal prey of houbara 136bustards in UAE

L is t o f T a b le s (continued)

Table 5.2 Mean and standard error (SE) of the recovery rate for prey 140

remains in faeces with key fragments in bold

Table 5.3 The correction factor and recovery rate for fragments 141

recovered for group 6 (large nocturnal tenebrionids)

Table 5.4 Estimated percentage of invertebrate matter of houbara 142

faeces from Abu Dhabi

Table 5.5 Plant remains identified from wild houbara faeces, listed as 143

percentage frequency by faeces and by track

Table 5.6 Percentage frequency of each prey group by faeces and by 144

track with prey identity where known

Table 5.7 Comparison of three methods of faecal analysis, with 145

estimates of the percentage contribution to biomass, fat and

protein

Table 5.8 Calorific value of invertebrate diet corrected for metabolizable 146

energy content per average faecal sample for wild houbara

over-wintering in Abu Dhabi

Table 5.9 Calculated values for typical daily diet, percentage frequency 147

of prey in pitfall traps and the estimate daily foraging distance

for houbara

Table 5.10 List of animal and plant foods from houbara faeces and 154

gizzards

Table 5.11 The percentage contribution of animal prey by group from 155

gizzard samples and estimated energy value with

comparative values for faecal samples

Table 5.12 Score for percentage invertebrate material and identity of 155

plant material present in gizzard contents

Table 6.1 Trophic relationships in Abu Dhabi (excluding houbara) 168

10

L ist o f F ig u r es

Figure 1.1 Map of Abu Dhabi and the United Arab Emirates showing the 18

five study sites

Figure 3.1 Mean catch of total invertebrates, Coleoptera and 75

Hymenoptera caught during 50 simulations of trap catch

Figure 3.2 The overall mean catch of beetles for line 1 against number 76

of traps

Figure 3.3 The cumulative number of species caught along three lines of 77

60 pitfall traps

Figure 4.1 Relationship between the average catches at the sites and 97

climatic conditions

Figure 4.2 Differences in log catch at the five sites (Fisher’s LSD test) 99

Figure 4.3 Cluster analysis of the sand and gravel communities at five 101

desert sites

Figure 4.4 The relationship between log number of taxa of predaceous 113

arthropods vs. sample number for catches at full and new

moons

Figure 4.5 PCA ordination of the invertebrate communities grouped by 115substrate and phase of the moon

Figure 4.6 Summary of invertebrates caught in the Heath trap by order 120

Figure 4.7 Annual cycle of the mean trap catch per calendar month 122

across all sites from two years of trapping, and the mean

minimum air temperature

Figure 4.8 Plot of mean and standard error of the light trap at five sites 123

over 24 sampling periods

Figure 4.9 Differences in log catch at the five sites 124

Figure 4.10 Plot of mean value for the number of insect orders recorded 125

by site

Figure 4.11 Differences in number of coleopteran families caught at the 126

five sites

Figure 4.12 Plot of mean value for the number of coleopteran families 126

recorded by site

Figure 5.1 Mean ratio of recovery rates for fragments from group 6 139

Figure 5.2 Available invertebrate prey and relative effort required to 148

catch them during the winter months in Abu Dhabi

L is t o f P la tes

11

Plate 1.1 The houbara bustard Chlamydotis undulata macqueeni 28

Plate 4.1 The Baynunah study site 91

Plate 4.2 The Medinet Zayed study site 91

Plate 4.3 The Public Hunting Triangle study site 91

Plate 4.4 The Khatam study site 91

Plate 4.5 The Urn Az Zimul study site 91

12

L ist o f A p p e n d ic e s

Appendix 1.1

Appendix 1.2

Appendix 4.1

Appendix 5.1

Appendix 5.2

Appendix 5.3

Appendix 5.4

Appendix 5.5

A preliminary assessment of the arthropods of Abu 205

Dhabi (Tigar 1996a)

Terrestrial Arthropods (excluding insects) (Tigar 1996b) 230

List of species caught in UAE (1992-1996) 243

List of feeding calibration trails 250

A preliminary study of the passage time of digesta of 251

the houbara (Tigar 1995)

Description of invertebrate remains recovered from 259

faecal samples

Photographs of typical fragments from the invertebrate 260

prey groups

List of faecal samples collected in UAE 264

13

Ac k n o w le d g e m e n ts

I thank HH Sheikh Khalifa Bin Zayed and HH Sheikh Mohammed Bin Zayed for

funding research at the National Avian Research Center (NARC), and the

Managing Director, Mr Mohammed AI Bowardi, for his support. I am also grateful

to Paul Goriup, former Chairman of the International Advisory Committee, for

guiding NARC towards bustard ecology and conservation. I also thank him for

sharing his extensive collection of bustard literature.

Particular thanks go to Dr Patrick Osborne, who has juggled the roles of friend

and confidant with those of manager, statistical adviser, proof-reader and

occasional field-assistant, all with equal enthusiasm and ability. I could not have

completed this work without his love and support.

Prof. Charles Godfrey of Imperial College at Silwood Park, acted my adviser and

I thank him for sound technical advice and support. Thanks also go to Prof. John

Lawton CBE, and staff and students at Centre for Population Biology for making

me feel welcome during visits to Silwood. Special thanks go to Dr Stuart McNeill

for his comments and suggestions. Drs Mike Bonsall and Hefin Jones, Anne

Elliot and Emma Croxson are thanked for their friendship and kindness.

At NARC, I was ably assisted in data collection by Andy Griggs, Matt Love, Will

Mitchell and Ollie Wardman. Will’s efforts during the faecal calibration are much

appreciated. Derek Gliddon’s ERDAS skills facilitated the image analysis trials.

John Norton, Dr Mike Oatham and Benno Boer identified plant material, and

John collected and processed the plant epidermes. Dr Fred Launay, Ron

Loughland and Simon Aspinall provided some houbara faeces. Special thanks go

to Jude Hewlett and Maggie Black for their excellent counsel and support.

My thanks also go to the Avian Ecology Group at Stirling University, particularly

Prof. Peter Hudson for his enthusiasm and support. Special thanks go to Dr Tim

Benton for his interest in desert ecology and suggestions for improving draft

chapters. Drs. Dan Thompkins and Ian Stevenson are thanked for their

comments on several chapters, while Mandy Fox, Sue Haysom, Lou Rowe, Zoé

Russell and Laura Sanders provided friendship and advice, along with copious

cups of tea and coffee in moments of despair. The design skills of Bill Jamieson

14

and Dave Aitchison of the Environmental Science Department are much

appreciated (Figures 1.1 & 4.1, Plates 1.1 & 4.1 and Appendix 5.4), and Tracey

Grieve helped to print several of the Figures.

Finally, I want to acknowledge taxonomists around the globe for their knowledge

of and enthusiasm for the Arabian fauna. John Boorman collated numerous

strange specimens that I sent to the Natural History Museum, London, and

ensured that they reached the appropriate specialists (Dr Anne Baker, Dr

Annette Walker, Gary Stonedahl, I. White, John Chainey, Michael Schaffer, M.

Wilson, Nigel Wyatt, Paul Hillyard, Sharon Shute and Richard Thompson), with

particular thanks to Dr George Popov MBE (Orthoptera) and Ted Wiltshire CBE

(Lepidoptera). In addition, Drs Julio Ferrer (Swedish Museum of Natural History,

Tenebrionidae) and Lou Sorkin (American Museum of Natural History, Aranaea)

are thanked for their proficient determinations. Last but not least, I thank Cedric

Collingwood (Leeds City Museum) and Dr Donat Agosti (American Museum of

Natural History) for introducing me to the wonderful world of ants.

15

C h a p t e r 1

G e n e r a l In t r o d u c t io n

Synopsis of Chapter 1

This chapter starts by explaining the rational behind the research, the aims of the

thesis and why there is an urgent need for a better understanding of houbara

bustard ecology. This is followed by a summary of the ecology and biology of the

United Arab Emirates (UAE), especially the terrestrial invertebrates. The Chapter

ends with a discussion of the family Otididae and the houbara bustard.

16

1.1 Identifying the problem; the rational behind the research

Our current understanding of houbara ecology is poor (Collar 1980; Cramp &

Simmons 1980; Johnsgard 1991; Osborne 1996a; Goriup 1997) and is based

mainly on observational data with few scientific studies. However, the species'

range is enormous and threats from habitat loss and hunting are both

widespread and on-going. Accurate data are needed to ensure the success of

international conservation efforts.

In recent years there has been considerable interest in the captive rearing of

houbara, and breeding centres have been established in UAE (Osborne 1996b),

Saudi Arabia (Biquand etal. 1992; Saint Jaime etal. 1996), Kazakhstan (Gubin

& Mukhina in prep.) and Morocco. This is in response to a perceived reduction in

numbers of houbara, which is the favoured prey species of traditional falconry

and of immense cultural importance in the Arabian Gulf (Badr 1976; Remple &

Gross 1993; Osborne 1996a & b). Despite considerable investment and effort,

the success of ex situ breeding and release programmes for rare species is low,

usually because of a lack of understanding of habitat requirements and biology

(Scott & Carpenter 1987). Release programmes can also have undesirable

effects including the overwhelming of unique local populations by non-native

genotypes, and the death of released individuals because the habitat cannot

support them, e.g. the barn owl in UK (Griffiths etal. 1996). Better information on

the ecology and biology of wild houbara is vital if captive-bred birds are to survive

and flourish following release. Research into the role of invertebrates in the diet

could reveal whether the low density of houbara in Abu Dhabi is linked to the

seasonal availability of certain prey species. It could highlight areas of

importance to over-wintering birds and ways to enhance and restore habitats for

houbara. The study may help improve diets for captive birds, e.g. seasonal

changes probably play an important role in bringing birds into breeding condition.

In addition, natural foods may contain micro-nutrients which artificial foods

generally lack (Anderson 1995).

While knowledge of the houbara is poor, even less is known about the

invertebrates of the UAE (see Tigar 1996a & b and Gillett 1996). However, there

is growing recognition of the prominent role invertebrates play in desert

ecosystems (Polis 1991a; Aldryhim, etal. 1992). Their small size belies their

17

importance, and in some desert locations the biomass of ants is ten times that of

mammalian herbivores (MacKay 1991). Invertebrates are also useful indicator

species for assessing habitat quality and biodiversity (Perfecto & Vandermeer

1996; Wilson 1992; Polls 1991a). An understanding of local invertebrates is

essential if we are to protect and maintain fragile habitats from environmental

change. As Abu Dhabi continues to develop, urbanisation, disturbance through

human activity and overgrazing of range lands are becoming increasingly

common (Oatham 1996; Osborne 1996a; Collingwood etal. 1997).

The aims of the thesis are to investigate patterns of seasonal abundance,

distribution and diversity of desert invertebrates in Abu Dhabi and to determine

their importance in the diet of houbara. Secondary objectives are to develop a

reliable method of faecal analysis for the study of houbara diet and to establish

monitoring techniques for the most important invertebrates.

Gizzard contents of wild houbara were also examined, and while emphasis was

placed on the diet of wild birds in their natural environment, captive houbara were

used as models to produce a calibration method for quantifying faecal analysis.

An estimation of the nutritional value of invertebrates was used to test the value

of the technique and to suggest ways of improving diets for captive birds. Where

possible, Abu Dhabi's invertebrates were compared to the invertebrate

communities of other deserts. In addition, a database for invertebrate

observations in UAE and a reference collection of invertebrate specimens and

photographs were established at the National Avian Research Center (NARC).

1.2 Abu Dhabi and the United Arab Emirates

Introduction

The UAE is a federation of seven emirates covering an area of 77,700 km , with

Abu Dhabi emirate occupying over 86% of the land (Figure 1.1). The Tropic of

Cancer crosses the southern tip of UAE which is part of the Great Palaearctic

Desert stretching from North Africa to western Pakistan. Over 90% of the country

is below 250m above sea level (ASL) and consists of flat plains overlain by sand

dunes, interspersed with lagoons and sabkhas (salt flats) at the coast.

18

52° E 53° E 55° E 56° E54° E

26° N - - 26° N

25° N - - 25° N

Public ----- '■ ;■Hunting [

f Triangle j

- 24° N24° N - Baynunah Khatam •

Medinet Zayed

O M A NA B U D H A B I

- 23° N23° N -Dm Az Zimul

km 100S A U D I A R A B I A

53° E 55° E52° E 54° E 56° E

Figure 1.1 Map of Abu Dhabi Emirate showing the five principal study sites;

Baynunah, Medinet Zayed, Public Hunting Triangle, Khatam and Dm Az Zimul

19

The smaller mountainous region of the country reaches about 1500m ASL and

is deeply dissected by several seasonal river valleys or wadis.

Traditionally, society was based on nomadic pasturalism, with herds of camels,

goats and sheep in the desert and limited cultivation at oases such as Liwa

(Anon 1993a). Following the exploitation of oil reserves in the 1960s, economic

development and population growth rose sharply, indirectly causing a lowering

of the water table and an increase in ground water salinity. Now desalination

produces over 80% of the water, much of which is used to irrigate vast forestry

plantations and agricultural developments in Abu Dhabi emirate. Between 1973

and 1990 the area of agricultural land increased from 13,000 to 43,000 ha

(Anon 1993a). Most people live in towns and no longer depend on the desert for

their livelihood.

Clements (1983) has produced a bibliography on the UAE, and there is also a

comprehensive atlas (Anon 1993a).

Geoloqv

The following description of Abu Dhabi’s geology is based on Glennie (1996),

while Anon (1993a) and Feulner (1997) give descriptions for the UAE as whole.

Five land forms occur in Abu Dhabi: sand dunes, interdune areas, coastal

sabkha, inland sabkha and exposed rock. The sand dunes are made of quartz

grains, with a higher carbonate content near the coast. The largest dunes are

static and support scant vegetation, while the smaller dunes (up to 20m high)

are quite mobile. The interdune plains are formed from either fluvial gravels or

low, scrub-covered sand drifts. They often contain gypsum crystals indicating a

history of inland sabkha.

The coastal sabkha occupies a band up to 30km wide along most of Abu

Dhabi’s coastline, at or above high tide level. It is an extremely saline and

evaporative environment, often covered in a crusty layer of halite (salt) and

characterised by a high concentration of carbonates and extensive sheets of

black algal mat. Inland sabkhas lack this algal mat and frequently occupy

interdune areas.

20

Apart from the low mountain at Jebel Hafit, Abu Dhabi emirate is a sandy desert

and three types of exposed rock-based soils occur in the rocky outcrops which

are of Tertiary, Mesozoic and Cambro-Precambrian age.

The two most important abiotic factors affecting the flora and fauna are soil

salinity and compaction. The latter determines whether the substrate is suitable

for burrows and also the ease of root penetration.

Climate

The harsh hyper-arid desert exerts great pressure on life, and many of its

inhabitants are adapted to avoid high temperatures and conserve water.

Bottomley (1996) has described the recent climate of Abu Dhabi. Winter occurs

from December to March, with unsettled periods of rain and strong winds. In

April and May temperatures start to rise and between June and September the

maximum temperature can exceed 40°C. October and November are

characterised by lower temperatures and light winds.

Mean maximum temperatures occur in July (42°C for coastal Abu Dhabi; 44°G

for AI Ain about 100km inland) with mean minimum temperatures in January

(14°C for Abu Dhabi; 12°C for AI Ain). The absolute maximum and minimum dry

bulb temperatures are 47.5°C and 49°C, and 7°C and 3°C for Abu Dhabi and AI

Ain cities respectively. In south-western Abu Dhabi Emirate, near the Rub AI

Khali or Empty Quarter, temperatures are even higher and can exceed 52°C

(Mandaville 1990). The interior may reach close to freezing-point in winter, when

daily temperature fluctuations occur caused by strong, north-westerly winds

known as shamals.

Relative humidity (rh) is highest during the summer along the coastal strip, often

exceeding 90% rh at 30°C, while inland rh below 10% can occur in May

because of a heat low over the Rub AI Khali (Bottomley 1996).

Abu Dhabi receives extremely variable amounts of infrequent rains and a whole

year’s rain can fall in one rain event. The mean annual rainfall is <100mm and

rain mainly falls between December and May. The average number of days on

21

which rainfall is recorded is only ten a year. Rainfall totals are highest in the

north-eastern and lowest in the south-western parts of Abu Dhabi. Summer rain

is rare but storms may occur near AI Ain because of cloud from the Indian

monsoon. The Rub AI Khali is extremely arid and its endemic plant community

is dominated by a few drought adapted shrubs; however complete destruction of

vegetation over great expanses may occur if rains fail repeatedly for several

years (Mandaville 1990).

The cloudless skies, intense solar radiation, high temperatures and low humidity

result in very high evaporation rates, which may exceed the mean annual

rainfall by 35-100 times (Mandaville 1990). This extreme evapo-transpiration

stress is a limiting factor to all forms of life (Holdridge etal. 1971 ; Schulze &

McGee 1978).

Winds are generally light but gusty shamals can reach speeds of 20-25 knots,

occasionally over 40 knots. The strongest winds (>60 knots) are associated with

squall lines or thunder storms. Although mean wind velocity is low, material

carried by winds can damage plant and animal cuticles. Summer shamals can

cause severe moisture stress to already drought stressed plants (Mandaville

1990).

Mist and fog form during the winter and at the end of summer. Dew is an

important form of moisture for desert life, and many shrubs act as centres of

condensation. For example, the sand under Haloxylon persicum Bge. bushes is

often covered with green algae (personal observation). Some desert animals

are able to use dew and although “fog basking” (Hamilton & Seely 1976; Seely

1979) has not been recorded in Arabian tenebrionids, beetles of the genus

Erodius probably extract water from specially constructed tunnels on dune

ridges (Büttiker & Anderson 1988).

Ecoloav

UAE contains elements from three biogeographic zones: the northern

Palaearctic, African and Asian, as well as Arabian endemics, and is potentially a

centre of high biodiversity. In his review of the UAE Satchell (1978) found few

accounts of its ecology, but recent publications include accounts of the natural

22

history of the Emirates (Jongbloed 1987; Vine 1997; Western 1989) and the

ecology of Abu Dhabi (Osborne 1996c). The Emirates Natural History Group

keep reference material and records of flora and fauna.

Introductions to the flora can be found in El Ghomeny (1985), Western (1989)

and Jongbloed (1987, 1997). Mandaville (1990) describes the flora of eastern

Arabia and provides much useful information, as does the Flora of the Arabian

Peninsula and Socotra series (Miller & Cope 1996). Satchell etal. (1981) give a

systematic description of land classes across the UAE, while Roshier et al.

(1996) describe nine characteristic plant species associations of Abu Dhabi. The

Emirates contains plants from both the Saharo-Arabian and Sudanian plant-

geographical regions (Zohary 1973) but their transition is poorly defined and

masked by the hyper-arid conditions in the Rub AI Khali. The Saharo-Arabian

region is a centre of diversity for the genera Suaeda, Fagonia and Zygophyllum.

Much of the fauna of Arabia has only recently been described (see Fauna of

Saudi Arabia series, published since 1980, edited by Wittmer & Büttiker).

However, the birds of the Emirates and Abu Dhabi are fairly well known

(Richardson 1990; Aspinall 1996; Osborne etal. 1996; Richardson 1997) and

there are various publications on land and sea mammals (Gross 1987;

Duckworth 1996; Baldwin 1997; Gross 1997a), fish (Shepley 1997), reptiles and

amphibians (Baha El Din 1996; Gross 1997b) and invertebrates (Gillett 1996;

Tigar 1996a & b).

Invertebrates

Desert arthropods have various mechanisms to conserve water and avoid heat

stress. Their small body size allows them to move into cooler microclimates

during the day and many live in deep burrows or near the roots of plants and

only emerge at night when the temperature has dropped. However, some

invertebrates are able to survive the heat of the day, including ants of the genus

Cataglyphis (Delye 1968) and scorpions which can tolerate higher temperatures

than most other desert arthropods (Polis 1990a). Many predatory arthropods

survive long periods without feeding if prey is scarce (Polis & Yamashita 1991).

23

Arabian invertebrates are not well known but are an abundant and important

component of the desert ecosystem. The majority of Arabian records originate

from scientific expeditions in Saudi Arabia and Oman (see Büttiker & Krupp

1980; Dutton & Bray 1988; Shaw Reade etal. 1980), and records from the UAE

are scant and often come from unrepresentative habitats, such as cultivated or

irrigated areas, where water and exotic vegetation allow non-desert species to

thrive. Taxa by taxa accounts of the invertebrates of Abu Dhabi and the UAE

are given in Tigar (1996a & b; Appendices 1.1 & 1.2) and a summary is

provided here. Information from neighbouring Saudi and Oman was used where

data were lacking.

Arachnids are well represented, with examples from the Scorpiones, Solifugae

and Araneae. Scorpions are perhaps best known, and four families probably

occur in Abu Dhabi: Buthidae, Chactidae, Diplocentridae and Scorpionidae

(Sissom 1990). Buthids are most numerous with 14 Arabian genera, including

the highly venomous Buthacus, Androctonus and Leiurus (Simard & Watt 1990).

Vachoniolus globimanus has been recorded in Abu Dhabi (Levy et al. 1973;

Vachon 1980). Other Arabian arachnids remain poorly described. The solifugids

or camel spiders are common and probably include the families Galeodidae,

Solpugidae and Rhagodidae (Cloudsley Thompson 1987), while desert spiders

may include the Gnaphosidae, Sparassidae, Thomisidae, Hersiliidae, Salticidae,

Lycosidae, Agelenidae, Theridiidae, Tetragnathidae and Argiopidae (Cloudsley

Thompson 1984). Free living mites from arid zones are poorly known but Giant

Velvet Mites Dinothrombium spp. emerge during the rains, and ixoid ticks are

better known because of their importance as vectors of infectious diseases (see

Tigar 1996b).

Many insects live in Abu Dhabi's deserts, including a few entognathans such as

Collembola, which probably survive in humid, underground microclimates (Zak &

Freckman 1991). Thysanura are common and Irish (1991) describes 11 Arabian

species but has no records from UAE, although the Lepismatidae undoubtedly

occur. Other insects in UAE include 12 of the 52 species of Arabian Odonata,

including several long distance migrants (Waterston & Pittaway 1989). Isoptera

are common with 20 Arabian species (Chhotani & Bose 1983, 1991) although

only Heterotermes aethiopicus is recorded from UAE (Boocock 1979). There

are 46 species of mantids in Arabia (Kaltenbach 1984, 1991), and while there

24

are no records for UAE, the curious and cryptically coloured ground mantis,

Eremiaphila bauri Krass, is common on gravel plains and other species live on

plants (Walker & Pittaway 1987).

The Orthoptera contains some important desert species which are occasionally

very numerous, including two locusts Schistocerca gregaria Forskâl and

Locusta migratoria Linnaeus, which are known from Abu Dhabi (see Uvarov

1952, 1966 & 1977). Popov (1980) lists 69 species of Acridoidea from Eastern

Arabia of which 28 occur in UAE. Tettigoniidae, Gryllidae and Gryllotalpidae are

also common across Arabia (Popov 1981; Walker & Pittaway 1987).

Hemiptera are not particularly well adapted for desert life and only occur where

there is abundant vegetation or prey. Matile-Ferrero (1984 & 1988) described 60

species of Aphididae and Coccidae, and Linnavuori (1986) 452 species of

Heteroptera from Arabia but there were no records for UAE. However, the

Arabian cicada Platypleura arabica Myers occurs in stands of trees and a large

shield-bug, Coridius viduatus Fabricusa (Dinidoridae), lives on native or

cultivated cucurbits (Walker & Pittaway 1987).

Two Neuropteran families occur in UAE: Chrysopidae and Myrmeleontidae.

Most larval Myrmeleontidae, or ant lions, construct conical, pit-like traps in the

sand to catch ants, but a few species have active, predatory larvae. Holzel

(1982, 1983 & 1988) lists 156 species from Arabia but UAE species are not

mentioned.

Coleoptera in UAE are abundant and diverse and include Carabidae,

Cicindelidae, Histeridae, Scarabaeidae, Buprestidae, Elateridae, Coccinelidae,

Tenebrionidae, Meloidae and Curculionidae. Large desert carabids, like Anthia

duodecimguttata Bonelli and Scarites spp. are common and tiger beetles, such

as Cicindela lunulata Fabricius and Cicindela immanis (Bates), occur on

intertidal mud flats and sabkhas. The Scarabaeidae include dung beetles, like

Scarabaeus cristatus Fabricius which is very numerous. However, tenebrionids

or darkling beetles are the most abundant and successful desert coleopterans.

They obtain all their water via their metabolism, and the chamber below the

fused elytra of flightless species probably aids water retention. They are

generally detritivores and are usually black or dark-coloured, and crepuscular or

25

nocturnal in habit. Kaszab (1981 & 1982) lists over 300 species for Arabia but

has split some species into several subspecies without providing a key or

description. He lists 18 species from DAE and the most common are Mesostena

puncticollis SoWer, Tentyrina palmeri Crolch, Trachyderma (=Ocnera) philistina

Reiche & Saulcy, Pimelia arabica Klug, Blaps koiiari Seidlitz and Prionotheca

coronata (Olivier). The genus Erodius is also abundant in some areas.

A few Arabian Diptera are well known, particularly disease vectors such as the

Ceratopogonidae and Chironomidae (Boorman 1989; Cranston & Judd 1989).

The Bombyliidae or bee flies have been studied by Greathead (1988) who lists

21 species from UAE. Other families such as Tabanidae, Asilidae and

Calliphoridae also frequent desert areas. Pont (1991) lists 68 species of

Muscidae and the most abundant species are Musca domestica domestica

Linnaeus, Musca domestica calleva Walker, Musca lucidula Loew and Musca

sorbens Wiedermann.

Lepidoptera are fairly well known. Larsen (1983) has written a monograph of

151 butterfly (Rhopalocera) species, and Wiltshire (1983, 1986, 1988 & 1990)

has reviewed the 625 species of Macro-Heterocera from the Arabian Peninsula.

Lepidoptera in UAE include the Cossidae, Pyralidae, Hesperiidae, Papilionidae,

Pieridae, Lycaenidae, Nymphalidae, Geometridae, Lasiocampidae, Sphingidae,

Lymantriidae, Arctiidae, Noctuidae and Psychidae.

Desert Hymenoptera include many ants, wasps and bees, some of which are

well known, for example, the Apidae, Anthophoridae, Megachilidae, Pompilidae,

Chrysididae, Scoliidae, Eumenidae, Vespidae and Sphecidae (see Richards

1984a & b; Guichard 1988a & b,1989a & b; Hamer 1982, 1986a & b; Roche

1981). Ants are an important ecological group and surveys of Saudi Arabia and

Oman revealed 156 and 28 species respectively (Collingwood 1985 & 1988),

although 275 species are now known from Arabia (Collingwood & Agosti 1996).

Tigar & Collingwood (1993) list 14 species from UAE, but these are only a small

proportion of those that occur. They include domestic pests, such as some

Monomorium spp., nocturnal predatory species like Camponotus xerxes Forel

and desert specialists of the genus Cafag/yp/i/s which forage during the day.

26

Other arthropods include a small number of Crustacea such as woodlice

(lsopoda:Porcellionidae), and Chilopoda (centipedes), especially the genus

Scolopendra.

1.3 Introduction to the bustards - family Otididae

This is a brief synopsis of current knowledge. More detailed reviews of the

bustards can be found in Cramp and Simmons (1980), Osborne etaL (1984),

Collar et a i (1986) and Johnsgard (1991), while a comprehensive bibliography

was published by Schulz & Schulz (1991). Specific reviews of houbara biology

have been compiled by Gubin & Mukhina (in prep.), Morris (1991) and Collins

(1984), although the latter mainly covers the Canarian houbara.

Bustards belong to the family Otididae, a homogeneous and ancient lineage

consisting of 22 species representing 6-8 genera (Collar et a i 1986; Osborne

1996a). They are divided into 47 subspecies or races according to differences in

size, plumage and geographic location (Osborne et a i 1984), although their

phylogeny remains in dispute (Cramp & Simmons 1980; Johnsgard 1991).

They are medium to large birds which are characteristic of open plains and

semi-desert, although some African species live in thorn scrub. They are

distinguished by the presence of unusual hexagonal scales on their legs, the

absence of a crop, the absence of a preen or oil gland and by having only three

toes, since a hind toe is lacking. Bustards cannot oil themselves but are covered

in a friable material called “powder down”, which along with dust-bathing is

thought to keep the plumage clean. The young are précédai and nidifugous and

must be bill-fed by the female for their first few weeks. Insects are thought to be

the most important part of the diet for chicks but adult birds are probably

omnivorous, although accurate data are lacking.

27

1.4 The houbara bustard

The houbara is a large bird with a distinctive turkey-like build (Cramp &

Simmons 1980) (Plate 1.1). Males weigh up to 2.36kg and females 1.8kg, but

mean weights are proportionately lower and vary with season; birds are heaviest

in winter (Johnsgard 1991). Houbara are cryptically coloured with a sandy-buff

plumage, and blackish vermiculations or blotches, a black stripe down side of

neck and a relatively long tail. Their white crown-tuft is diagnostic but is not

always visible (Osborne etal. 1984). Juveniles and females are smaller than

males with less well developed crests and ruffs. Birds are sexually mature in

their second year (Johnsgard 1991).

Subspecies and their ranges

Collar (1980) gives an account of the houbara’s general distribution updated by

Goriup (1997). Its taxonomy is described by Goriup & Collar (1980) who

recognise three subspecies, but Gaucher etal. (1996) suggest that Chlamydotis

undulata macqueeni may be a separate species because of differences in its

genetics and behaviour. The nominate North African race, Chlamydotis

undulata undulata, ranges from Mauritania to Egypt, with most of the population

in Morocco. It is sedentary or locally nomadic with a population of about 10 000

birds (Goriup 1997).

The rarest race is the Canarian houbara, Chlamydotis undulata fuertaventurae,

which is sedentary and confined to Fuerteventura, Lanzarote and Graciosa in

the Canary Islands. In the 1980’s there were only 100-300 birds (Collar 1980,

Dominguez 1989) although there are now about 750 (Goriup 1997).

“Macqueen’s” bustard, C.u.macqueeni, ranges from eastern Egypt to Jordan,

Baluchistan, Kazakhstan, Mongolia and eastern China, and Goriup (1997) gives

a population estimate of 39-52,000. The ranges of C.u.undulata and

C.u.macqueeni probably overlap in the Nile valley.

C.u.macqueenI can be migratory, sedentary or locally nomadic. It is paler and

slightly larger than the other races, with a black centre to its white crown tuft, an

olive-green bill and pale creamy-grey feet and legs (Osborne etal. 1984).

28

Plate 1.1 Houbara bustard

29

In Arabia C. u. macqueeni \s primarily a winter visitor, with only small breeding

populations in Saudi, Oman and Yemen (Osborne 1996a). It was also thought

to have bred in Syria, Iraq and Iran but populations are now very low (Collar

1980; Johnsgard 1991; Goriup 1997). The Republics of Kazakhstan and

Uzbekistan, and the Kyzyl-Kum and Turkmenistan deserts are probably the

main breeding areas before the birds move to India or Pakistan. Satellite

tracking has shown that birds over-wintering in Abu Dhabi migrate to

Turkmenistan (Osborne etal. 1997a). Both resident breeding and winter

populations occur in Pakistan, although the latter outnumber breeding birds.

Houbara habitat

The houbara is a bird of harsh, arid, sandy or stony deserts and steppes and is

thought to be among the best adapted birds for desert life. It is associated with

sparse xerophytic and halophytic vegetation such as low shrubs like Artemisia

spp., Tamarixspp., or Haloxylon spp., but may frequent arable land (Osborne et

al. 1984). The climatic and vegetative features of the houbara’s range appear to

correspond with the Irano-Turanian, Saharo-Arabian and Sudanian

phytogeographical regions defined by Zohary (1973) (Osborne 1996a).

EcoIoqv of Chlamydotis undulata macqueeni

Houbara are powerful fliers and can migrate several thousand kilometres

(Osborne etal. 1997a), but they are also cursorial and walk great distances

(Osborne etal. 1984). During migration they form flocks of up to 60 birds

(Cramp & Simmons 1980) but usually occur in loose groups of four to ten birds

which feed and roost together outside of the breeding season (Osborne etal.

1984). Typical population densities are low; between 0.3 (Mian & Surahio 1983)

to 1.7 birds per km in Pakistan (Mirza 1985), and 0.032 to 0.097 birds per km

in Saudi Arabia (Seddon & van Heezik 1996).

Houbara are very wary and are difficult to flush, preferring to crouch behind a

bush or stone, but if forced they will quickly fly out of view. Their capacity for

concealment and cryptic coloration make them surprisingly hard to locate in the

field. Houbara are the favoured prey of Arab falconers, even though such large

birds are difficult quarry. Indeed, houbara may also squirt sticky, caecal faeces

30

over pursuing falcons, causing them to give up the chase unless their feathers

are cleaned by the falconer (Osborne etal. 1984).

In Central Asia breeding occurs from April to June (Gubin & Mukhina, in prep.)

and generally coincides with the spring rains. During the breeding season,

males display at traditional sites with about 500m between rival males. The

unusual “running display" of males is carried out repeatedly through the day

(Osborne etal. 1984). The male initially lowers the tail and spreads and raises

its crown and neck feathers into upward curves. It then retracts its head and

completely puffs out its neck plumage. The mating system is thought to be

polygynous or promiscuous (Collar etal. 1986) but may be monogynous at low

population densities (Osborne 1996a). After copulation the female rears the

young alone. Eggs are olive brown with dark blotches, and are laid in a shallow

scrape with 2 or 3 eggs per clutch. Incubation takes 23 days and the young

fledge in about 35 days but remain with the mother for longer. Details of

Houbara behaviour are described in Cramp & Simmons (1980), Osborne etal.

(1984), Collins (1984), Collar etal. (1986) and Launay & Paillat (1990).

Unusually for a bustard, houbara are virtually silent. Females make a low “quop”

or “quip” like call and chicks a plaintive peeping noise (Cramp & Simmons

1980).

Houbara are generally considered to be opportunistic omnivores. However,

much of the information on their diet is based on historic descriptions of single

samples. In Chapter 2 ,1 review the literature relating to houbara diet and try to

summarise patterns of food consumption by taxa across the range. Some

authors suggest that houbara do not drink and obtain all the moisture they need

from their food or morning dew (Valverde 1957; Mian 1988). However, they also

drink at water holes (Cramp & Simmons 1980) and in captivity.

The conservation and status of the houbara

The houbara is currently on Appendix II of CITES and is subject to strict export

control. It is variously reported as endangered in different parts of the range and

has some degree of protection although is still hunted in many countries. For

example it is listed in the Red Data Book for the USSR and is considered

31

“endangered” in Mongolia (see Johnsgard 1991 for further details). However,

Goriup (1997) has suggested that population estimates for the former USSR

should be at least 20 times higher than previous calculations (Flint etal. 1992),

and that while the Canary Islands subspecies should be listed as “Vulnerable”

according to lUCN criteria, the houbara from other parts of the range are more

numerous and should be listed as “Vulnerable” or “Near threatened” according

to local population levels.

Accurate data on the distribution and status of the houbara are lacking across

much of the range, and population estimates are both difficult and expensive to

obtain because of the patchy distribution of the houbara across desert terrain

(Osborne 1996a). However the population is thought to have declined greatly

during the 20* century (Collar 1980; Goriup 1997). The most probable causes

are excessive hunting (especially from motor vehicles), overgrazing of habitat,

agricultural development, industrial development, egg collecting and the general

pressure of human settlement (Collar 1980). However, hunting records from

Pakistan suggest that the population may have been underestimated because

such high mortality could not have been sustained, and evidence from Central

Asia also suggests that the bird is more numerous (Osborne 1996a). Other

bustard species, such as the great bustard Otis tarda, have also declined over

the last 50 years following agricultural and land-use changes (Hidalgo de

Trucios 1990; Alonso & Alonso 1996), and co-ordinated, international action is

essential to prevent the continued demise of these birds across their ranges

from organisations such as the Bustard Specialist Group (run by the lUCN

Species Survival Commission and BirdLife International) (Goriup 1997).

32

CHAPTER 2

T h e d ie t o f t h e h o u b a r a b u s t a r d - a r e v ie w


This chapter reviews current literature on the houbara diet. The known food

items of each houbara subspecies are given in turn, followed by detailed

information on animal and plant foods and any examinations of gizzards or

faecal samples. Semi-captive, captive and vagrant birds are mentioned,

especially where natural foods were eaten, and information on gizzard stones is

presented. The discussion compares the methods used to study the diet and

presents an analysis of known items in the diet based on the frequency of

citations for each taxon consumed. This calculated value or citation index

makes it easier to compare between the houbara subspecies. The conclusion

summarises general dietary trends for the species, including seasonal patterns

and specific requirements of birds according to age and reproductive status.

33

2.1 Introduction

Several authors have reviewed the diet of the houbara bustard including Cramp

& Simmons (1980), Collins (1984), Roberts (1991), Morris (1991), Johnsgard

(1991) and Gubin & Mukhina (in prep.). Houbara are often described as

omnivorous, although much of the literature is speculative, observational or

based on single samples, and there are few attempts to quantify the diet. The

only replicated results are some examinations of faeces (see Gubin & Mukhina

in prep.; Collins 1984) and gizzard contents (see Fox 1988; Mirza 1971).

2.2 The review of the diet

All non-speculative data on foods of the houbara were summarised into tables

(Table 2.1 green plants; Table 2.2 fruits, seeds and flowers; Table 2.3

invertebrates and Table 2.4 vertebrates). Some of the literature is unpublished

and has not been peer-reviewed, and may contain inaccuracies. However, it is

often the only source of information on the houbara. Except for the houbara,

scientific nomenclature is not abbreviated to avoid confusion caused by the

large number of genera.

2.2.1 The Canary Island houbara: Chlamydotis undulata fuertaventurae

General descriptions of the diet

Collar (1983) provides a useful translation of early work on C.u. fuertaventurae,

gleaned from the notebooks and letters of bird collectors. General descriptions

of the diet include beetles, wheat and oats (Webb & Berthelot 1836-1844),

snails, lizards and a trefoil (Meade-Waldo 1889a), lizards, plants, seeds and

dung beetles (Volsoe 1951) and invertebrates, snails, lizards {Lacerta atlantica),

geckos {Tarentola delanderei), rabbits, house-mice, rats and hedgehogs

{Erinaceus algirus) (Hooker 1958). However, Hooker (1958) may have implied

that houbara were foraging on necrophilic invertebrates living in carrion, rather

than preying upon live mammals (see Sushkin 1908). Bannerman (1963) states

that houbara eat peas, beans, snails, beetles (dung beetles), caterpillars, a

trefoil and fruits of Lycium intricatum (Solanaceae).

34

Plant name

"Green plants"

Young green shoots

Chlamydotis undulata Chlamydotis undulata Chlamydotis undulatafuertaventurae undulata macqueeni

Vols0e (1951) Valverde (1957), Bédé (1928), Lavauden (1914) Brosset (1961)

Alekseev (1985), Roberts & Savage (1971) Dharmakumarsinhji (1955), Ferguson-Lees (1969), Mian (1988), Roberts(1991), Goriup & Norton(1992 )___________________

MonocotyledonsGramlneaeGrass

Wheat and other crops (see also Table 2 .2)Bromis tectorum Cymbopogon sp. Koeleria phleoides Lasiurus sp.Poa bulbosaOedibasis apiculata

Collins (1984, 1993) Anon (1980)

Lavauden (1914)

Salikhbaev & Ostrapenko (1967), Afanas'ev & Sludskiy (1947), Zhuyuko (1986)Baker (1912), AN & Ripley (1969), Ferguson-Lees (1969), Glutz von Blotzheim etal. (1973) Gubin & Mukhina (in prep.) Mirza (anecdotal) (1985) Mian & Surahio (1983) Mirza (1971)Gubin & Mukhina (in

prep.)Gubin & Mukhina (in

Liliaceae Tulipa Allium sp.(garlic, onion and other Allium sp.)

Gubin & Mukhina (in prep.) Sushkin (1908), Ferguson- Lees (1969), Meinertzhagen (1954), Giutz von Blotzheim etal. (1973)

DicotyledonsAizoaceaeMesembryanthemumspp.

Meade-Waldo (1889a & b), Collins (1984, 1993)

Asclepiadaceae Leptadenia sp. Leptadenia spartinum

Mirza (anecdotal) (1985) Dharmakumarsinhji (1955)

Apocynaceae Rhazya striata Mian & Surahio (1983)

Capparaceae Capparis sp.

Capparis aphylla Capparis decidua Capparis spinosa Dipterygium glaucum

Molchanov (1913), Fox (1988)Surahio (1985)Mian (1988)Seddon, P. (pers. comm.) Launay, F. (pers. comm.)

Chenopodiaceae Anabasis sp. Mian (1988)

Haloxylon sp. Gaucher (1991) Mirza (1971), Surahio (1985), Mian (1988)

Table 2.1

List of plants eaten by the three subspecies of houbara as vegetative material

35

Plant name Chlamydotis undulata Chlamydotis undulata Chlamydotis undulata fuertaventurae undulata macqueeni

ChenopodiaceaeHaloxylon Mian & Surahio (1983)

ammodendronSalsola sp. Mian (1988)

Salsola arbuscula Mian & Surahio (1983),Gubin & Mukhina (in prep.)

Salsola richeri Gubin & Mukhina (in prep.)

Salsola rigida Gubin & Mukhina (in prep.)

Compositae Artemisia sp. (shoots)

Calendula aegyptiaca Lactuca sp.Lactuca serricola Launaea sp.

Collins (1993)

Collins (1993)

Sushkin (1908), Meinertzhagen (1954), Ferguson-Lees (1969), Glutz von Blotzheim e ta l (1973), Gavrin (1962)

Fox (1988)Pavlenko (1962)

Goriup & Taylor (1983)

Cruciferae Collins (1993)

Brassica, mustard, Ali & Ripley (1969),

oilseed and cabbage. Ferguson-Lees (1969), Glutz von Blotzheim e ta l (1973), Surahio (1985)

Brassica campestris Roberts & Savage (1971).

Brassica juncea Mian (1988)

Eruca sativum Mian (1988)

Farsetia sp. Mirza (1971), Gallagher(unpubl.)

Farsetia aegyptia Goriup & Norton (1992)

Farsetia jacquemontii Fox (1988)

Hirschfeldia incana Lack (1983)

Lobularia lybica Collins (1984, 1993)

Malcomia africana Mian & Surahio (1983)

Malcomia sp. Mian (1988)

Notoceras bicorne Collins (1984, 1993)

Gyperaceae Carex pachystilis Carex physodes

Gubin & Mukhina (in prep.) Gubin & Mukhina (in prep.)

Ephedraceae Ephedra sp. Mian & Surahio (1983)

Euphorbiaceae Euphorbia granulata Euphorbia prostrata

Fox (1988)Mirza (anecdotal) (1985)

Geraniaceae Erodium sp. Erodium cicutarium Collins (1984, 1993)

Mian & Surahio (1983)

LeguminosaeTrefoil Meade-Waldo (1889a),

Bannerman (1963)

Table 2.1 (continued)


36

Plant name Chlamydotis undulata fuertaventurae

Chlamydotis undulata undulata

Chlamydotis undulata macqueeni

Leguminosae Cultivated beans and peas (see Table 1b)

Acacia sp.Alhagi mauraurum Astragalus hamosus Crotalaria sp.

Indigofera sp. Medicago minima Medicago sativa Alfalfa

Polatzek (1909), Bannerman (1963), Lack (1983), Collins (1984)

Collins (1984,1993)

Collins (1984, 1993) Collins (1984) (anecdotal)

Symens (1987) (captive) Dharmakumarsinhji (1955)

Mirza, (1971), Gallagher (unpubl.), Surahio (1985) Symens (1987) (captive)

Symens (1987) (captive), Launay (1989a, b & c) (captive)

Plantaginaceae Plantago ciliata Plantago sp. Collins (1984, 1993)

Mian & Surahio (1983) Fox (1988)

Polygonaceae Calligonum comosum Polygonum afghanicum

Mian & Surahio (1983) Mian & Surahio (1983)

Solanaceae Tomato leaves Lycium shawii

Valverde (1957)Symens (1987) (captive)

Tiliaceae Grewia populifolia Triumfetta rotundifolia

Surahio (1985) Dharmakumarsinhji (1955)

Zygophyllaceae Fagonia sp.

Fagonia indica Tribulus sp.

Tribulus alatus Tribulus terrestrisZygophyllum sp.

Mirza (1971), Gallagher (unpubl.)Symens (1987) (captive) Mirza (1971), Surahio (1985), Mian (1988)Mian & Surahio (1983) Fox (1988), Mian & Surahio (1983)Pavlenko (1962), Meklenburtsev (1990), Mirza (1971)

Unknown Eulaliopsis sp. Mirza (1971)



37

Plant name Chiamydotis unduiata fuertaventurae



Flowers

Fruits & Seeds

Seeds

Berries

Vols0e (1951)

Whitaker (1905), Anon (1980)Glutz von Blotzheim et al (1973)

Glutz von Blotzheim et a! (1973), Brosset (1961)

Ali & Ripley (1969), Goriup & Norton (1992)Cornwallis (1982)

Dharmakumarsinhji (1955), Ferguson-Lees (1969), Roberts & Savage (1971), Mian (1988)Glutz von Blotzheim e ta l (1973)

MonocotyledonsGramineae Grain and Cereals

Wheat

Oat

BarleySorghum seeds Sorghum bicolor Panicum sp. (seeds) Grass (spikelets)

Palmaceae Dates (fruit)

Polatzek (1909)

Webb & Berthelot (1836- 44)Webb & Berthelot (1836- 44)Cramp & Simmons (1980)

Whitaker (1905), Glutz von Blotzheim et a / (1973)

Jourdain (1915)

Dharmakumarsinhji (1955),

Fox (1988)

Mian & Surahio (1983) Goriup & Norton (1992), Afanas’ev & Sludskiy (1947), Zhuyuko (1986)


DicotyledonsAnacardiaceae Pistacia atlantica (nuts)

Glutz von Blotzheim e ta l (1973), Gillett(1988)

Capparaceae Cadaba sp. (fruits) Capparis sp. (fruits)

Fox (1988)Dharmakumarsinhji (1955), Molchanov (1913)

Chenopodiaceae Anabasis articulata (fruits)Haloxyionammodenderon(seeds)

Gillett(1988)


Cistaceae Heiianthemum ruficomum (buds & flowers)

Gaucher (1991)

CompositaeAchilieafragrantissima(flowers)Argina spinosa (flowers and fruits)

Heim de Balsac & Mayaud (1962), Glutz von Blotzheim et a / (1973)

Goriup & Norton (1992) (casual observation)

Table 2.2

List of flowers, fruits and seeds eaten by the three subspecies of houbara

38

Plant name Chlamydotis undulata Chlamydotis undulata Chlamydotis undulatafuertaventurae undulata macqueeni

Compositae Gagea reticulata (flowers and fruits) Matricaria sp.(flowers)Lactuca serricola (panicles)Launaea spp.(flowers)Launaea arborescens (flowers)____________

Gillett (1988)

Valverde (1957), Goriup & Taylor (1983)

Gubin & Mukhina (in prep.)

Pavlenko (1962)

Hemmingsen (1958), Collins (1984, 1993)

Cruciferae Farsetia aegyptia (fruits)Farsetia hamiltoni (fruits and flowers) Farsetia stylosa (fruits and flowers)

Goriup & Norton (1992)


Gaucher (1991)

Geraniaceae Erodium oxyrrhynchum (seeds)______


Leguminosae Fruits and seeds Peas

Acacia sp. (seeds) Argyrolobium uniflorum (fruits) Astragalus macroladus (seeds) Astragalus turczaninovii (flowers) Cicer arietinum (Chick pea seeds) Lens culinaris lentil seedsMedicago lactinata (fruits)Reaumuria turkestanica (flowers) Ziila spinosa (flowers and fruits)

Volsoe (1951) Polatzek (1909), von Thanner (1913)

Pavlenko (1962)

Gaucher (1991)

Lack (1983) (anecdotal)

Lack (1983) (anecdotal)

Anegay (1992)



Fox (1988)

Goriup & Norton (1992)


Goriup & Taylor (1983) (observation)

Moraceae Ficus sp. (fruits) Anon (1980)

PolygonaceaePolygonum Mian & Surahio (1983)

afghanicum (seeds)



39

Plant name Chlamydotis undulata fuertaventurae



Polygonaceae Polygonum sp. Buckwheat (seeds) Calligonum comosum (seeds)



Rhamnaceae Zizyphus jujuba (berries)Zizyphus lotus (berries)Zizyphus numularia (berries)Zizyphus sp. (berries)

Gillett (1988)

Glutz von Blotzheim et al (1973), Ali & Ripley (1969)

Surahio (1985)

Cramp & Simmons (1980), Mian (1988), Fox (1988)

Sapotaceae Argina spinosa (fruits and seeds)

Heim de Balsac & Mayaud (1962)

Solanaceae Lycium spp. (fruits) Lycium afrum (fruits) Lycium intricatum (fruits)Heteracia szovitsii (fruits)

Collins (1984; 1993) von Thanner (1912; 1913) Bannerman (1963)

Valverde (1957)


Scrophulariaceae Antirrhinum ramosissium (flowers, fruits and seeds)

Goriup & Taylor (1983) (observation)

Tiliaceae Grewia populifolia (fruit)

Glutz von Blotzheim e ta l (1973), Ali & Ripley (1969)

Umbelliferae Bupleurum sp. Lavauden (1914)

Zygophyllaceae Fagonia sp. (seeds) Fagonia sp. (fruits and flowers) Zygophyllum sp. (seeds)

Gillett (1988), Gaucher (1991)

Mirza (1971)

Pavlenko (1962), Meklenburtsev (1990)



40

Prey item Chlamydotis undulata fuertaventurae



Invertebrates Hooker (1958) Gallagher (unpubl.)

Insecta

Insect larvae Larvae on carrion

Bédé (1928), Brosset (1961)

Roberts & Savage (1971), Dharmakumarsinhji (1955), Mian (1988)Fox (1988)Sushkin (1908)

Orthoptera Acrididae Grasshoppers and locusts

Cramp & Simmons (1980), Collins (1984,1993), Valverde (1957)

Toschi (1969), Anon (1980)

Boehme (1926), Meinertzhagen (1954), Ali & Ripley (1969), Mirza (1971), Glutz von

Sphingonotus caerulans Cedopodinae sp.

Tettigoniidae, Bush crickets Gryllotalpidae, Molecrickets

Heim de Balsac (1926),

Blotzheim et a! (1973), Mian (1988), Gubin & Mukhina (in prep.). Dement’ev & Gladstock (1951), Fox (1988), Pavlenko (1962), Salikhbaev & Ostapenko (1967), Gavrin (1962), Symens (1988a) (captive) Glutz von Blotzheim e ta ! (1973)

Glutz von Blotzheim et at (1973)Glutz von Blotzheim et al (1973)

Mian (1988), Roberts & Savage (1971)

Odonata Gubin & Mukhina (in prep.)

Isoptera, Termites Salikhbaev & Ostapenko (1967), Ali & Ripley (1969), Glutz von Blotzheim e ta l (1973), Gubin & Mukhina (in prep.)________________

ColeopteraBeetles

Webb & Berthelot (1836- 44), von Thanner (1912; 1913), Volsoe (1951).

Timarcha pygidium Pentodon ciliata

Valverde (1957), Anon (1980), Goriup & Taylor (1983)

Lavauden (1914)

Meinertzhagen (1954), Rustamov (1954), Ali & Ripley (1969), Mirza (1971), Glutz von Blotzheim et a / (1973), Mian (1988), Roberts(1991), Goriup & Norton(1992)

Glutz von Blotzheim et al (1973)__________________

Cerambycidae Dorcadion sp. Plocaederus scapularis Acinopus striolatusCarabidae Carabus sp.

Cymindis sp.______

Gavrin (1962)Gubin & Mukhina (in prep.)


Glutz von Blotzheim e ta l (1973)


Table 2.3

List of invertebrates eaten by the three subspecies of houbara

41

Prey item Chlamydotis undulata Chlamydotis undulata Chlamydotis undulatafuertaventurae undulata macqueeni

CarabidaeHarpalus sp. Glutz von Blotzheim e ta l

(1973)Machozetus lehmanni Gubin & Mukhina (in prep.)

Scarites bucida Gubin & Mukhina (in prep.)

Scarites terricola Gubin & Mukhina (in prep.)

Scarabaeidae Ali & Ripley (1969), Glutz von Blotzheim et al. (1973), Gubin & Mukhina (in prep.)

Dung beetles Webb & Berthelot (1836- Sushkin (1908)1844), Polatzek (1909), Volsoe (1954), Bannerman (1963)

Copris lunaris Glutz von Blotzheim e ta l(1973)

Aethiesa szekessy Gubin & Mukhina (in prep.)

Ootoma bipartita Collins (1984,1993)

Scarabaeus Fox (1988)

gangeticusScarabaeus sp. Gubin & Mukhina (in prep.)

Chafers Heim de Balsac (1926), Valverde (1957)


Chineosoma Gubin & Mukhina (in prep.)

kizilcumensePhaeadoretus Gubin & Mukhina (in prep.)

comptusMelanotha sp. Alekseev (1985)

BuprestidaeJulodis variolaris Gubin & Mukhina (in prep.)

Julodis onopordi Toschi (1969)

Chrysomelidae Glutz von Blotzheim etal.(1973)

Barathaea spp. Toschi (1969)

Staphylinidae Glutz von Blotzheim et al.(1973)

Curcuiionidae Collins (1984; 1993) Glutz von Blotzheim et al. (1973), Goriup & Norton (1992), Fox (1988), Anegay (1992), Gavrin (1962)

Ammocleonus sp. Fox (1988)

Cleonus sp. Gavrin (1962)

Chromosomus sp. Fox (1988)

Conorhynchus Collins (1984, 1993)

conirostrisLixus sp. Gubin & Mukhina (in prep.)

Tenebrionidae Gillett (1988), Gaucher (1991)

Sushkin (1908), Kostin (1956), Ali & Ripley (1969), Glutz von Blotzheim etal. (1973), Alekseev (1985), Anegay (1992), Gavrin (1962)

Anatolica sp. Gavrin (1962)


List of invertebrates eaten by the three subspecies of houbara.

42

Prey item

Tenebrionidae Adesmia sp. Adesmia aenescens Adesmia fagergreeni Adesmia panderi Akis sp.Arthrodesis sp.Blaps sp.

Pimelia bengasina Pimelia interpunctata Pimelia indica Pimelia inexpectata Pimelia sp. Prionotheca coronata Mesostena sp. Scorus sp.Thryptera kraatzi Tentyria sp. Trachyderma sp. Trachyderma robusta Zophosis plicataMeloidaeDermestidaeElateridae Mylabris sp.SilphidaeCantharidae

Chlamydotis undulata Chlamydotis undulata Chlamydotis undulatafuertaventurae undulata macqueeni

Symens (1987) (captive) Fox (1988)Fox (1988)Gubin & Mukhina (in prep.) Anegay (1992)Fox (1988)

Lavauden (1914) Glutz von Blotzheim etal.(1973), Fox (1988), Gubin & Mukhina (in prep.), Gavrin (1962)

Toschi (1969)Toschi (1969)

Fox (1988)Fox (1988)Anegay (1992)Anegay (1992)Anegay (1992)Anegay (1992)Fox (1988)Gavrin (1962)Anegay (1992)Fox (1988)

Gavrin (1962)



Samarin et a i (1986)

Ali & Ripiey (1969), Giutz ____________________________ von Biotzheim et a / (1973)

Coiiins(1984, 1993)

Lepidopteran larvae

Agrotis segetum Trachea atriplicisAdult Lepidoptera

von Thanner (1912,1913) Aiekseev (1985), Gubin & Mukhina (in prep.)Giutz von Biotzheim et al. (1973)Glutz von Blotzheim et al. (1973)

Fox (1988)

Hemiptera (Shield bugs)

Gubin & Mukhina (in prep.) Fox (1988)

Hymenoptera

Apidae, Bees

Vespoidea (wasps)

Ichneumonidae

Gubin & Mukhina (in prep.)Glutz von Blotzheim etal. (1973)

Zhuyuko (1986)



43

Prey item Chlamydotis undulata fuertaventurae



HymenopteraFormicidae, Ants

Camponotus sp. Messor maurus

Collins (1984,1993)

Collins (1984,1993)

Valverde (1957), Lavauden (1914), Ehrenberg in Neumann, (1834), Goriup & Taylor (1983), Gillett (1988), Gaucher (1991).

All & Ripley (1969), Roberts & Savage (1971), Glutz von Blotzheim etal. (1973), Mian (1988), Roberts (1991), Goriup & Norton (1992), Fox (1988), Anegay (1992), Gubin & Mukhina (in prep.)Anegay (1992)

Diptera, True flies Gubin & Mukhina (in prep.)

Arachnida Cramp & Simmons (1980) Brosset (1961)

Araneae, Spiders

Latrodectustredecimguttata(Cocoons)

Glutz von Blotzheim et al (1973), Anon (1980)

Pavlenko (1962), Meklenburtsev (1990)

Scorpiones ScorpionsCompsobuthusarabicas

Fox (1988)Anegay (1992)

Solifugae Camel spiders Gaieodes sp.

Anegay (1992), Gavrin (1962)


Galeodes grantii (?) Anegay (1992)

CrustaceaIsopoda Armadillium sp.

Hemilepistus elegansAlekseev (1985), Rustamov (1954) Gubin & Mukhina (in prep.)

Chilopoda,Centipedes

Ali & Ripley (1969), Gubin & Mukhina (in prep.)

MolluscaGastropoda(Pulmonata)Snails

Theba (Helix) pisana Helix sarcostema

Meade-Waldo (1889a), von Thanner (1912,1913), Cramp & Simmons (1980), Collins (1984, 1993) (anecdotal)Hooker (1958), Lack (1983) (anecdotal)Hooker (1958)

Glutz von Blotzheim at a! (1973), Anon (1980)

Ali & Ripley (1969).



44

Taxonomie Group Chlamydotis undulata fuertaventurae



Reptilia

Lizards

Cramp & Simmons (1980) Brosset (1961)

Meade-Waldo (1889a), von Thanner (1912; 1913), Volsoe (1951)

Agama sp.Eremias sp.

Eremias arguta Eremias velox Lacerta atlantica Phrynocephalus sp.

Phrynocephaius helioscopus Psammodromus sp. Tarentola delalandel GeckosTrapelus mutabilis Scincus scincus Snakes

Colubridae

Glutz von Boitzheim et al. (1973), Anon (1980), Goriup & Taylor (1983) possible observation.

Anon (1980)

Hooker (1958)

Hooker (1958)Anon (1980)

Fox (1988) Anon (1980)

Mian (1988), Baker (1912), Roberts & Savage (1971), Cornwallis (1982)Aharoni (1912) (captive), Sushkin (1908), Boehme (1926), Meinertzhagen(1954), Dharmakumarsinhji(1955), Ali & Ripley (1969), Glutz von Blotzheim et al. (1973), Gallagher (unpubl.) Gubin & Mukhina (in prep.) Gubin & Mukhina (in prep.) Salikhbaev & Ostapenko (1967)Gubin & Mukhina (in prep.) Gubin & Mukhina (in prep.)

Salikhbaev & Ostapenko (1967)Gubin & Mukhina (in prep.)

Glutz von Blotzheim etal. (1973)Aharoni (1912)

MammiferaCarrion of domesticanimalsHouse mouseJerboasRabbitsRatsErinaceus algirus Hedgehog Mus musculus

Hooker (1958)

Hooker (1958)

Hooker (1958) Hooker (1958) Hooker (1958)

Geptner (1959)


Table 2.4

List of vertebrates know to be eaten by the three subspecies of houbara

45

Animal foods

Animals are said to be important in the diet, and when pack-animals were

common in the Canaries, houbara visited their tracks to feed on dung-beetles

attracted by excrement (Webb & Berthelot 1836-44; Polatzek 1909). Von

Thanner (1913) states that houbara eat snails, beetles, caterpillars and lizards,

and older literature often mentions snails as a favourite food (Meade-Waldo

1889a; von Thanner 1912), identified by Hooker (1958) as Helix pisana and

Helix sarcostema (both Mollusca:Gastropoda). More recently, local wardens told

Lack (1983) that houbara ate Theba (=Helix) pisana (Müller), but he never saw

this himself. Likewise, local people told Collins (1984) that snails were eaten by

houbara, but he found no trace of snails in 106 houbara faeces.

Plant foods

Several authors list the plants eaten by houbara on Fuerteventura, including a

trefoil (Leguminosae) (either alfalfa Medicago sativa or the native Medicago

minima), a Mesembryanthemum sp. (Aizoaceae) possibly Mesembryanthemum

nodiflorum (Meade-Waldo 1889b; Collins 1984), Lycium a/rum fruits (von

Thanner 1912), Launaea flowers (Valverde 1957), a yellow herb Hirschfeldia

incana (Cruciferae) and perhaps other common shrubs like Launaea

arborescens (Compositae) and Salsola vermiculata (Chenopodiaceae) (Lack

1983). There are also reports of houbara feeding in and damaging crops such

as peas, lentils and cereals (Polatzek 1909; von Thanner 1912, Lack 1983).

Farmers told Collins (1984) that houbara ate chick-peas, lentils and alfalfa

especially in the dry season, but he did not observe this himself during a two

year field-study.

Studies based on faecal analvsis

The most extensive study of the diet of C. u. fuertaventurae is by Collins (1984,

1993) who examined 106 faeces from two field seasons. The majority were

collected at the roost sites of two males (45% and 19% of samples) which

biases his conclusions. He had difficulty in estimating the volume of different

foods because there were no data on their rates of digestion, but estimated the

number of some insects by counting remains of heads, hind tibiae or femora.

46

He estimated the percentage of plant matter and identified plant remains where

possible, but may have under-recorded easily digested foods.

He divided food into four main food types: insects, annual plants, Launaea

arborescens flowers and Lycium sp. fruits. Insects were present in 85% of

faeces and the most frequent were Conorhynchus conicirostris

(ColeopteraiCurculionidae), Zophosis plicata (ColeopteraiTenebrionidae) and

Messor maurus (HymenopteraiFormicidae), with a few Ootoma bipartita

(ColeopteraiScarabaeidae) and grasshoppers. Annual plants were present in

79% of faeces and were identified from their flowers except for Medicago

minima which had distinctive leaves. They included Lobularia lybica (Cruciferae)

(54%), Notoceras bicorne (Cruciferae) (43%) and Medicago minima

(Leguminosae) (43%). Flowers and buds of the spiny shrub Launaea

arborescens (Compositae) were found in 55% of faeces, while fruits of the

thorny shrub Lycium sp. (Solanaceae) occurred in 49% of faeces. Other plant

remains included fragments of Calendula aegyptiaca (Compositae) (20%),

grasses (14%), a Compositae (13%), Erodium cicutarium (Geraniaceae) (10%),

a Cruciferae (4%), Plantago spp. (Plantaginaceae) (3%), Mesembryanthemum

spp. (Aizoaceae) (2%) and Astragalus hamosus (Leguminosae) (1%).

Samples from the two birds that contributed 64% of faeces contained an above

average proportion of weevils (Curcuiionidae), which may reflect the frequency

of weevils in their home ranges or a food preference. Even though many foods,

appeared plentiful some faeces contained only limited items, suggesting

possible prey preferences. For example, there were over 600 Lycium sp. fruits,

150 Zophosis plicata beetles and ten weevils in one faecal sample. During the

rainy season, the estimated amount of plant matter decreased from 82% to 58%

in the bird which contributed 45% of samples, contrasting with Heim de Balsac

& Heim de Balsac’s (1954) suggestion that houbara eat more vegetable than

animal matter during the spring. More Zophosis plicata and fewer ants were

found in the faeces in the wet season, which may indicate a switch from ants to

tenebrionids, since ants were numerous throughout the year while beetles were

only seasonally abundant.

47

Some faeces contained larvae of coprophagous invertebrates (dung-flies and

beetles) which were probably attracted to the faeces rather than being eaten by

the houbara.

Feeding behaviour of C.u.fuertaventurae

The feeding behaviour of C.u.fuertaventurae has been observed by a few

authors. Von Thanner (1913) noted that houbara were inactive during the

hottest part of the day, and Hinz & Heiss (1989) confirmed that they were least

active at noon, and fed mainly in the morning (06.00-8.00 hrs) or afternoon and

early evening (16.00-18.00 hrs). Houbara often stayed in one area, particularly

fields of alfalfa, lentils and chick-peas, where they ate insects and plants. Collins

(1984) described their feeding behaviour, but was unable to get close enough to

see what they were eating because they were easily disturbed.

2.2.2 The North African houbara: Chlamydotis undulata undulata


C.u.undulata is the least known of the three subspecies and information on its

diet is lacking. General descriptions include plants and insects (Button 1835;

Bédé 1928; Heim de Balsac & Mayaud 1962), and Argania spinosa

(Compositae) fruits in the dry season (Heim de Balsac & Mayaud 1962).

Descriptions of single gizzard contents include; green plants, bush-crickets

(Orthoptera) and large chafers (Scarabaeidae) in the spring (Heim de Balsac

1926); green plants (40%), >100 ants (30%), beetles (20%), and fruits of

Lycium sp. (10%) in June (Valverde 1957); insects, arachnids, reptiles, berries

and young green shoots (Brosset 1961) and ants (Glutz von Blotzheim et ai.

1973).

Other foods include cereals, seeds, pistachio nuts, berries, spiders, snails,

lizards and snakes (Glutz von Blotzheim et ai. 1973) and Launaea sp. flowers

(Valverde 1957), while houbara chicks hunt locust hoppers and eat tomato

leaves (Valverde 1957). Anon (1980) mentions that houbara eat young grass

shoots and the leaves of shrubs in the spring, while in summer and autumn they

consume wild seeds, figs and other windfall fruit in orchards. Small snails.

48

grasshoppers, spiders and beetles, and small lizards such as Psammodromus

sp., Agama sp. and skinks Scincus scincus are also mentioned (Anon 1980).

However, this may be a summary of potential food, since Combreau &

Rambaud (1995) were surprised that C.u.macqueeni gizzards (n=11) did not

contain any of the locally abundant skinks.

Gaucher (1991) tracked an incubating female in the Algerian Sahara and found

feeding damage to buds, fruits and flowers of Farsetia stylosa (Cruciferae),

Argyrolobium unifolium (Leguminosae), Fagonia glutinosa (Zygophyllaceae) and

Heiianthemum ruficomum (Cistaceae), and to fresh shoots of Haloxylon sp.

(Chenopodiaceae). He saw signs of feeding at ants' nests and thought that the

female foraged close to her nest rather than searching for more distant prey.

Observations of houbara in Morocco during April suggested that they often ate

the fruits and flowers of two shrubs, Zilla spinosa (Leguminosae) and Farsetia

hamiltonii (Cruciferae) (Goriup & Taylor 1983). After the rains houbara also

consumed the fruits and flowers of Antirrhinum ramosissium (Scrophulariaceae)

and foraged on the ground, possibly catching lacertid lizards. Gizzards

contained fruits and flowers of Farsetia hamiltonii, flowers and leaves of

Launaea sp. (Compositae), dates, other plant remains, ants and beetles.

Gizzard content analvsis

Lavauden (1914) described two gizzards from houbara in Tunisia. The first

contained two Blaps sp. (Coleoptera:Tenebrionidae), two Timarcha sp.

(Coleoptera:unknown), three “grains”, two umbellifer seeds (probably

Bupleurum sp.) and a green vegetable pulp, possibly young barley shoots. The

other gizzard contained a green pulp, two ants, one Timarcha pygidium and five

“grains”. In March at Bengazi-Agedatia, Toschi (1969) found the following

insects in houbara gizzards: Jolodis onopordi (Coleoptera;Buprestidae), another

buprestid, Pimelia bengasina, Pimelia interpunctata (Coleoptera:

Tenebrionidae), Barathaea sp. (Coleoptera:Chrysomelidae) and grasshoppers

or locusts (Orthoptera:Acrididae).

Gillett (1988) examined 23 gizzards from Algerian houbara in December 1987,

which contained tenebrionids and ants, although he only identified plant

49

remains. There were many fiower-buds of the small shrub Farsetia stylosa

which have high levels of protein (21.1% dry weight) and minerals (20.6% dry

weight). Shoots and fruits of perennial shrubs like Anabasis articulata

(Chenopodiaceae) and Fagonia sp. (Zygophyllaceae), and leaves of Matricaria

sp. (Compositae) were also consumed. He suggested that houbara select

young plant growth such as seedlings, flower-buds and shoots following the

rains, since annuals like Poiycarpaea sp. (Caryopyllaceae) and Trifolium sp.

(Leguminosae) appeared in samples at this time. Gizzards also contained fruits

of Zizyphus lotus (Rhamnaceae) and Pistacia atlantica (Anacardiaceae). Fox

(1988) examined gizzard contents of Algerian houbara which contained lizards

{Trapelus mutabilis) and a scorpion (probably Buthidae). According to his

previous experience. Fox thought that C.u.undulata consumed more reptiles

than C.u.macqueenI.

2.2.3 MacQueen’s bustard: Chlamydotis undulata macqueeni

C.u.macqueenI \s generally migratory, has a wider distribution and is more

common than the other houbara subspecies (Osborne 1996a). Its long

association with Arab falconry has attracted much attention. There are detailed

studies of its diet from several parts of the range particularly the Middle East,

India and Pakistan, and Central Asia, which are considered below. Note

however, that the ranges of some of these populations overlap (see discussion

of houbara distribution in Osborne 1996a).

The Middle Eastern population

General descriptions of the diet include Artemisia sp. shoots, allium bulbs,

beetles (Tenebrionidae), lizards, grasshoppers and locusts (Meinertzhagen

1954), while snakes (colubrids) were a favourite food of houbara in Der-es-Zor

on the Euphrates (Aharoni 1912). In Harrat Al-Harrah, Saudi Arabia, Symens

(1988b) noted that houbara nested in areas with diverse vegetation. Females

and chicks remained close to their nest for over a week after hatching, and ants

appeared to be an important food. Nothing is published on the diet of the

resident houbara of Jiddat AI Harasis in Oman, but potential foods include the

leaves, shoots and corns of Fagonia sp. (Zygophyllaceae), Crotalaria sp.

(Leguminosae), Tribulus sp. (Zygophyllaceae) and Farsetia sp., and

50

invertebrates and small lizards (M. D. Gallagher unpubl. MS). Lavee (1985)

trapped houbara using baby-mice, fly larvae and Blaps sp. (Coleoptera:

Tenebrionidae) but these may not be normal constituents of the diet.


In Saudi Arabia, Goriup & Norton (1992) noted that houbara foraged in well-

vegetated parts of sabkhas. Ten houbara faeces were examined, of which

seven consisted solely of plant matter, while three contained only insect

fragments. Plant remains included fruits and leaves of Farsetia aegyptia

(Cruciferae), fruits of Medicago lacinata (Leguminosae) and grass spikelets,

while several faeces only contained flower petals (probably Achillea

fragrantissima, Compositae). The faeces containing insects were composed

almost entirely of ants, with parts of a weevil and a large beetle. Goriup &

Norton (1992) suggested that houbara may develop a search image for a

specific food item, such as ants, because of individual preferences or locally

abundant food sources.

The Pakistani and Indian populations

There is much dietary data from this region, including descriptions of gizzard

contents and known foods. However, many studies lack details of methodology

or data analysis, and have not been peer-reviewed. As in the Canary Islands,

houbara feed on crops and may cause considerable damage (Baker 1912), and

crops are used as a lure when catching houbara (P. E. Osborne pers. comm.).

General description of the diet

Indian houbara are said to be omnivorous with a preference towards green

plants, and only eating reptiles when very hungry (Baker 1912). In Saurashtra,

houbara have been recorded feeding upon insects, lizards, Capparis sp.

(Capparaceae) fruits, Leptadenia sparticum (Asclepiadaceae), Triumfetta

rotundifolia (Tiliaceae), mustard, manna {Alhagi mauraurum Leguminosae),

seeds and grains (Dharmakumarsinhji 1955). Ferguson-Lees (1969) states that

houbara over-wintering in India feed on plants, especially Artemisia sp., berries

and seeds of desert plants, wild onions and crops such as mustards, oilseeds

51

and wheat. Ali & Ripley (1969) mention other foods including the fruits of

Zizyphus jujuba (Rhamnaceae) and Grewia populifolia (Tiliaceae), as well as

ants, termites, locusts, grasshoppers, beetles (Tenebrionidae, Scarabaeidae,

Cantharidae and others), and more rarely centipedes, lizards and snails.

Houbara eat seeds and green plants (up to 30% of the diet) including crops,

e.g. Brassica juncea (L.) (Cruciferae) and Cyamopsis tetragonoloba (L.)

(Leguminosae), combined with insects (such as mole-crickets (Orthoptera:

Gryllotalpidae) and ants) and small reptiles (Roberts & Savage 1971). Game-

wardens and hunters thought that over-wintering houbara were omnivorous,

eating seeds, young shoots and slow-moving insects, while in southern and

eastern Baluchistan houbara probably consumed beetles, mole-crickets, ants

and grasshoppers (Mian 1988).

Plant foods

Several authors list plants eaten by the houbara but some may be potential

rather than proven foods. Mian & Surahio (1983) report that in Dak, Zangi

Nower and Kharan, houbara eat young shoots of Calligonum comosum

(Polygonaceae), Koeleria phleoides (Gramineae), Malcolmia africana

(Cruciferae), Haloxylon ammodendron (Chenopodiaceae), Ephedra sp.

(Ephedraceae), Salsola arbuscula (Chenopodiaceae) and Polygonum

afghanicum (Polygonaceae) as well as the dry seeds of Polygonum afghanicum,

Calligonum comosum, Haloxylon ammodendron and Panlcum sp. (Gramineae).

In the Chagai and Yakmuch plains, plants such as Tribulus terrestrls, Tribulus

alatus (Zygophyllaceae), Erodlum sp. (Geraniaceae), Plantago dilata

(Plantaginaceae), Rhazya strlcta (Apocynaceae) and Holosteum umbellatum

(Caryophyllaceae) were probably eaten. Mirza (1985) suggests that food plants

in Pakistan include Leptadenia sp. (Asclepidaceae), Cymbopogon sp.

(Gramineae) and Euphorbia prostrata (Euphorbiaceae). Surahio (1985)

mentions that houbara in Sind (Pakistan) feed on Zizyphus numularla berries

(Rhamnaceae), Capparis aphylla (Capparaceae), Crotolarla sp., Haloxylon sp.,

Grewia populifolia and Tribulus sp., and that mustard crops attract high

numbers of foraging birds. Mian (1988) lists locally available food plants for

several regions of Baluchistan. In Zhob, Pishin, Nushki and Kharan, Salsola sp.,

Haloxylon sp.. Anabasis sp. (Chenopodiaceae), Malcolmia sp., and Tribulus sp.

were said to be important, while in the lowland deserts to the South and East

52

(Gwadar, Dera Bugti, Sibi, Kachi) houbara eat Zizyphus sp. berries, and

vegetative parts of Brassica campestris (Cruciferae), Capparis decidua

(Capparaceae) and Eruca sativum (Cruciferae).

Studies based on gizzard contents

Mirza (1971) examined 100 gizzards of houbara hunted using falcons in

Pakistan. Most contained a mixture of plant and animal matter, such as

grasshoppers and beetles, although about 12.5% consisted entirely of plant

material, including Fagonia sp. (Zygophyllaceae), Haioxylon sp.

(Chenopodiaceae), Farsetia sp. (Cruciferae), Zygophylium sp.

(Zygophyllaceae), Tribulus sp. (Zygophyllaceae), Crotaiaria sp. (Leguminosae)

and Eulaliopsis sp. (unknown). Fagonia sp. seeds occurred in 75% of samples.

Mirza (1985) also mentions a grass, Lasiurus sp., probably from the same

gizzards. Fox (1988) examined 52 gizzards from houbara in Chagai and

Dalbandin in Baluchistan, and Leiah and Rajanpur in the Punjab. They all

contained plants and insects, but vegetation made up 62.9% of the total dry

matter, particularly Farsetia jacquemontii {Cruc\ierae), Capparis sp.

(Capparaceae) and Tribulus terrestrls (Zygophyllaceae), which occurred in 74%,

74% and 84% of samples and contributed 26.5%, 11.9% and 9.9% to the total

dry matter respectively. Other plants included Haloxylon ammodenderon

(Zygophyllaceae), Zizyphus sp. fruits (Rhamnaceae), Euphorbia granulata

(Euphorbiaceae), Cadaba sp. (Capparaceae) and small amounts of chick peas,

water melon and sorghum. Insects contributed 31% of the dry weight with ants

in 84% of the samples. Beetles occurred in many samples, especially the

tenebrionids: Adesmia aenescens (22.6%), Pimelia indica or Pimelia

inexpectata (19.5%), Arthrodosis sp. (9.7%), Biaps sp. (6.5%), Thryptera sp. or

Trachyderma sp. (6.5%) and Adesmia fagergreeni (6.5%). Other beetles and

weevils occurred in 67.7% of gizzards and a few grasshoppers (16.1% of

samples), Hemiptera, adult Lepidoptera and insect larvae were also found.

Houbara gizzards from Pakistan contained leaves, shoots and ground-dwelling

insects such as ants and beetles (Roberts 1991). Seasonal variations in food

availability may influence the diet. In early winter, houbara gizzards contained

17% insects, increasing to 30% in mid-winter and 51% by late winter (although

there is no mention of how these figures were obtained). The amount and types

53

of plants consumed also varied, with a shift from the foliage of perennial shrubs

in early and mid-winter to newly sprouted herbs in the late winter. Houbara may

have a wide diet so that they can survive in arid regions by adapting to different

foods. Observations also suggest that houbara forage during the day

(particularly morning and evening) in undisturbed areas, but feed nocturnally

where human disturbance is high.

The Central Asian population

Central Asia probably contains the largest populations of houbara, including

important breeding grounds where houbara are locally abundant. These areas

facilitate the collection of dietary data since large sample sizes can be obtained

compared with areas frequented by low density migrant birds.


General descriptions of the diet include green plants, invertebrates (especially

tenebrionids) and lizards (Ponomareva 1982), "ber" fruits, Grewia sp. (Tiliaceae)

berries, lemon-grass and insects (Finn 1915), gerbils (Geptner 1959), lizards,

Tenebrionidae and dung-beetles, as well as carrion-inhabiting Silphidae

(Coleoptera) and insect larvae (Sushkin 1908; Samarin etal. 1986). In the

breeding grounds, houbara eat beetles (especially Scarabaeidae,

Tenebrionidae and Cantharidae) and Orthoptera (locusts, grasshoppers and

bush-crickets), plus a few ants, termites, lizards and small snakes (Glutz von

Blotzheim etal. 1973). In the stony desert of Betpak-Dala, Kazakhstan, houbara

were said to eat beetles, seeds and grasses (Afanas'ev & Sludskiy 1947), while

Boehme (1926) thought that houbara near the Iranian-Kazakhstan border at

Nakhichrev' ate lizards and grasshoppers.

54

Plant foods

Plant foods include Capparis sp. fruits (Capparaceae) in Aybugir, Uzbekistan

(Molchanov 1913), while Artemisia sp. (Compositae), wild onion and garlic (both Ailium

sp. Liliaceae) bulbs are eaten by houbara around the Aral Sea (Sushkin 1908;

Meinertzhagen 1954; Ferguson-Lees 1969; Glutz von Blotzheim etal. 1973). Indeed,

houbara flesh may become tainted by the mixture of pungent plants {Artemisia spp.

and Aliium spp.).

Studies based on gizzard contents

There are many descriptions of houbara gizzard contents from Central Asia, although

most consist of lists of prey from single birds (see summary in Table 2.5). In a few

cases, particular prey types dominated the gizzard contents suggesting a preference

or seasonal glut of food, especially grasshoppers (Acrididae) during the summer

(Bannikov & Skalon 1948; Pavlenko 1962; Piechocki 1968). Most gizzards contained a

mixture of plant and animals foods, and Tenebrionidae were frequently mentioned.


Gubin & Mukhina's (in prep.) work is based on over 1000 faeces of breeding birds from

four seasons in the Kyzylkum desert, Kazakhstan. Most samples were collected from

breeding males, but there were few from females, chicks or non-breeding birds.

Relative proportions of the constituents of the faeces were estimated by eye and the

frequency of encounter for each prey item was noted. (However, rather optimistically

frequency is quoted to the nearest 0.1%). The species identified from the faeces are

listed in Tables 2.1 to 2.4. Plant material was most abundant in the spring, making-up

about 80% of volume of all the samples, but dropped in June (7%) and September

(20%). Beetles occurred in at least 50% of samples, and were the most frequent

invertebrates in faeces. The highest volumes of beetles were seen between May and

June (56%). Tenebrionids were mainly eaten in May and the most frequently

encountered species was Adesmia panderi (up to 25% of the volume of faeces).

Houbara also consumed weevils (Curculionidae) and scarabs, but rarely ate the large

and abundant Scarabaeus sp. beetles. Buprestidae occurred in samples during May

and June, with a few Carabidae, Cicindelidae and Meloidea, and single records of

Dermestidae and Elateridae.

Collection Collection No. & sex Plants foods recorded Animal foods recorded Citationsite date of houbaraUkraine November 1 Male 6 buckwheat seeds 228 Lepidoptera larvae (227 Agrotis segetum, 1 Trachea atriplicis

Messenger moth), 34 beetles (10 Harpalus sp., 2 Carabus sp., 1 Pentodon cillata, 1 Copris lunaris, 3 Blaps sp., 14 staphylinids, 2 curculionids, 1 chrysomelid), 4 Acrididae (3 Sphingonotus caerulans ,1 Cedopodinae sp.) 1 wasp (Hymenoptera)

Glutz von Blotzheim et al. 1973

Ustyurt >1 Only tenebrionid beetles Kostin 1956

T urkmenistan 3 gizzards Filled with beetles. Some woodlice (Crustacea.lsopoda), grasshoppers, ants, termites and camel spiders (Arachnida:Solifugae)

Rustamov 1954

Golodnaya 20 September 3 gizzards Leguminosae seeds (34g) and leaves of Zygophylium sp. and Lactuca serriola

Acrididae (38g), 42 cocoons of the spider Latrodectus tredecimguttatus Pavlenko 1962

Kashirskaya March >1 Mainly grass Very few insects Salikhbaev & Ostapenko 1967

Kashirskaya Summer(June?)

10 gizzards Less plant material than in March Termites (400-500 per gizzard) dominated 3 of the 10 gizzards. Other animal prey included beetles, grasshoppers, termites & lizards (Phrynocephalus sp. and Eremlas sp.).

Salikhbaev & Ostapenko 1967

Kashirskaya October >1 Green shoots of herbs and shrubs Insects and lizards Salikhbaev & Ostapenko 1967

Kyzylkum 24 June 1959 1 Male Green plant material 8 tenebrionids, two caterpillars and 1 woodlouse Armadillidium sp. (CrustaceaJsopoda)

Alekseev 1985

Kyzylkum 26 April 1965 1 Male Green plant material 50 tenebrionids and 6 chafers (Coleoptera: Scarabaeidae) Alekseev 1985

Kyzylkum 23 May 1972 1 Female Green plant material 9 tenebrionids Alekseev 1985

Betpak-Dala May 2 gizzards A mixture of tenebrionids and curculionids Gavrin 1926

Betpak-Dala 20 September 1 gizzard Artemisia sp. leaves 3 scorpions, 1 solifugid and some tenebrionids Gavrin 1926

Hi valley 17 September 1 Male Many beetles: 140 Dorcadlon sp. (Cerambycidae), 3 AnatoHca sp. (Tenebrionidae) plus some Meloidae and Silphidae; a few Orthoptera

Gavrin 1926

Kazakhstan 2 September 1 Female 60 Tentyria sp. (Coleoptera:Tenebrionidae) Gavrin 1926

Kazakhstan 26 August 1 Female 84 weevils (4 Cleonus sp. Curculionidae) and 6 Blaps sp. (Tenebrionidae).

Gavrin 1926

Turkmenistan 3 gizzards Beetles Rustamov 1954

South of lake 17 May 1983 1 Female Grass Many Tenebrionidae, Ichneumonidae, Carabidae and Curculionidae Zhuyko 1986Balkhash

Mongolia 5 July-August Many Filled with grasshoppers (Acrididae) Bannikov & Skalon 1948

Mongolia 26 May >1 Plants including bulbs Insects, including Acrididae Piechocki 1968

Table 2.5 Summary of houbara gizzard contents from Central Asia.cncn

56

Gubin & Mukhina (in prep.) also found that arachnids were an important food,

as evidenced by the hard chelicerate mouthparts of Solifugidae, which occurred

in up to 80% of faeces in mid-June. Ants and termites were as important as

beetles early in the spring, contributing up to 19.7% by volume and occurring in

up to 50% of samples. Orthoptera, especially Acrididae occurred in over 30% of

samples in June (4% by volume). However, they are more easily digested than

beetles and may have been underestimated. In the heat of the summer ants

were one of the few invertebrate groups that did not decline. Woodlice were

eaten at a low frequency and volume, and Myriapoda, Mantodea, Lepidoptera

larvae, Diptera, Odonata, Apidae and Hemiptera were recorded infrequently.

Vertebrate prey were indicated by the remains of bones in faeces. For example,

a few lizard bones (see Table 2.4) were found in faeces from May and June,

and one faecal sample contained the tail of a house-mouse Mus musculus.

2.2.4 Vagrant houbara

Vagrants birds appear in areas outside of their normal range and have often

travelled great distances. When they arrive they are usually starving and out of

condition, and probably eat whatever is available. They are included in Table 2.6

for completeness, but are absent from other Tables.

Placename

List of food Citation

Yorkshire Gizzard contained mainly plant matter, particularly buds and flowers of Senecio aquaticus (Compositae).

Cordeaux 1896

Ukraine Gizzard contained many Lepidopteran larvae in November Glutz von Blotzheim etal. 1973

Suffolk Observed houbara eating winter-wheat, peas, mustard, barley stubble, earthworms and mice.

Axell 1964

UK Insects, including Orthoptera, Lepidoptera (yellow underwing larvae, Noctua pronuba (L.)), carabids and snails.

Roberts 1848; Witherby et al. 1943

Table 2.6 Summary of foods eaten by vagrant houbara

57

2.2.5 Gizzard stones

Houbara ingest small stones to aid the grinding action of their muscular gizzard

in common with other bird orders, such as Galliformes. Gizzard stones are

mentioned by Lavauden (1914) and Surahio (1985) while Fox (1988) found

stones in the 29% of 52 gizzards. They have also been found during post

mortems of captive and wild houbara in the UAE (NARC, unpublished data).

2.2.6 The diet of semi-captive houbara

There are many studies of wild houbara in captivity, and captive-bred birds in

quasi-natural conditions or managed habitats (summarised in Table 2.7). Some

pinioned, wild birds have been kept in areas of natural vegetation planted with

known food plants, and given ad lib supplies of concentrated food pellets,

supplements and irrigated alfalfa. Other free-flying, captive-bred birds have

been released into protected enclosures, with access to supplementary food,

managed habitats and natural foods. Many observational data have been

gathered, including feeding habits, but are likely to be biased towards foods that

are easily identified and to observations taken during daylight hours.

2.2.7 Diets for captive houbara

Various diets for captive houbara have been described (see Table 2.8). They

usually contain a mixture of what is thought to be required (based on studies of

poultry) and foods that can be obtained locally, particularly insects. They may

bear little resemblance to natural diets, for example, yellow mealworms

Tenebrio molitorare easily reared and are often given to houbara but are

unlikely to occur in the wild. Artificial diets are excluded from Tables 2.1 to 2.4

Several authors discuss imbalances in captive diets, such as deficiencies or

excesses of particular nutrients which cause diseases only observed in captivity.

Indeed, the low survival rate of captive chicks is probably diet related (Platt

1985; Nazarov 1992; Haddane 1985). Hermans (1988a) criticised houbara diets

at Taif as being too high in protein with a tendency to turn rancid. He also

suggested that the ratio of energy to protein should be altered according to

stages of growth and reproduction (Hermans 1988b & 1992).

Condition of houbara {C.u.macqueeni)

Food consumed Citation

Pinioned birds in pens at Taif Main foods in February were shrubs, especially Lycium shawii (Solanaceae), while in April Acacia sp. (Leguminosae), Fagonia indica (Zygophyllaceae), Indigofera sp. (Leguminosae), grasshoppers and Adesmia sp. (ColeopteraiTenebrionidae) were eaten.

Symens 1987

Pinioned birds in pens at Taif Houbara appeared to catch Schistocerca gregaria (Orthoptera:Acrididae) together in a collective manner.

Symens1988b

Pinioned birds in pens at Taif Birds spent 44.5% of time in January and February eating in alfalfa plots and 36% off shrubs. Time spent feeding on the ground 14.5%, on annual plants 5% and catching insects 4%.

Launay 1989a

Pinioned birds in pens at Taif Alfalfa preferred in March, changing to insects and grass in April and May. Percentage time spent foraging on insects varied monthly; January 2%, February 5%, March 38%, April 28% and May 16%.

Launay 1989c

Wild-caught, pinioned and captive- bred birds at Mahazat as Sayd

Irrigated native vegetation and alfalfa plots were preferred in the dry summer. Birds spent more time in alfalfa plots in September and October. Gizzards of 2 captive-bred birds contained, 1: a scorpion, a camel spider, many tenebrionids and ants. 2: vegetation, tenebrionids and ants. Faeces contained tenebrionids, ants (including Camponotus sp.) and acacia seeds.

Anegay 1992

Captive-bred, released birds at Mahazat as Sayd

Gizzards of birds contained: tenebrionids {Pimelia sp., Zophosis sp., Trachyderma sp. and Blaps kollari) and plants {Farsetia ramoisissima (Cruciferae), Lycium shaw/V (Solanaceae), Morettia parviflora (Cruciferae) and Fagonia sp. (Zygophyllaceae)) in the spring (n=3); and similar plants, plus Lycium sham/fruits and alfalfa, with more invertebrates, especially tenebrionids {Mesostena sp., Scaurus sp. & Akis sp.) and ants, plus a single carabid, coccinelid and scorpion in late July, September and November (n=8).

Combreau &Rambaud1995

Table 2.7 Summary of observational and other data on the diet of captive and semi-captive houbara

cr«00

Citation Placename

List of food items

Aharoni 1912 Der-es-Zor on the Euphrates

Haddane 1985 Morocco

Platt 1985 DubaiUAE

Paillat 1987 Pakistan

Ramadan-Jaradi & AI Ain ZooRamadan-Jaradi 1989 UAE

Nazarov 1992 Israel?

Diet given to chicksC .u. macqueenh lizards {Gonglycus ocillatus, Acanthodactylus syriacus and Ophigis elegans), beetles, grasshoppers and agamids (e.g. Agam a inermis), onion, grass, bread, hard-boiled eggs and table scraps. Preferred foods were: large tenebrionids {Blaps oribosa and Adesmia abbrevlata) and small rodents {Mus praetaltus, Dipus sp., Psammomys obsesus, Eumeces scrumeian and Terraesanotae sp.).C .u. unduiata: insects such as grasshoppers, beetles and ants.

C .u. macqueeni-A skinned quail, 4 boiled quails eggs with shell, 1/4 cup poultry layer pellets, 1/4 teaspoon bone-meal and liquid vitamins, plus live prey such as mealworms, grasshoppers and white mice.

C .u. macqueenh 1st week reptile, stomachs (containing insects) and an artificial diet with alfalfa and vitamins: 2"' week pieces of reptile and the artificial diet; 3rd week whole lizards and the artificial diet. Reptiles included snakes {Echis carinatus and Spaierosophis sp.).

C.u. macqueenh 1st week live grasshoppers, mealworms, minced raw meat and hard boiled eggs; 2nd week live insects with choppedalfalfa, lettuce and bread.

Insects, grasshoppers, pigeon or sparrow meat, cottage cheese, oatmeal, millet porridge, green plants, clover, onion, carrot, apples, _________________cherries, tomatoes, cabbage and beetroot. Chicks also captured small lizards and a snake in the aviary._____________________________________

Diet given to adultsFuerteventur C .u. fuertaventurae: mixed food e.g. cabbage, lettuce, locusts, lizards (up to 23cm long), omelette, grapes, meal, seeds, salt and humble a bees.

Tunisia C .u. unduiata: a mixture of foi (probably a plant), finely chopped liver, sodden bread, herbs and grain, accompanied by live insects.

Israel A mix for insectivorous birds, combined with ground carrots, green peppers, hard-boiled eggs, egg shells, meat, fish, small mice or rats(<15g), fly larvae, dog-food and lettuce or other greens were added. Alfalfa was planted in the aviaries.

AI Ain Zoo C .u. macqueenh mixed foods including minced raw meat, multivitamins, minerals, hard-boiled eggs, bread, lettuce, alfalfa, millet, canaryUAE seed, wheat, com, apples, grapes, orange, guava, pears , raisins, dog-food and pheasant-food, grasshoppers, mealworms and mice.

Bukhara C .u . macqueenh Insects, fish, frogs, rodents, poultry, meat, maize leaves, alfalfa, ‘Sudan grass’. Astragalus sp., Chrosophora gracilis andEcocentre, Atripiex sp.; flowers of Salsola praecox, Calligonum sp. and Delphinium sp; seeds of Haloxylon sp., Karelinia caspia Salsola sp., SuaedaUzbekistan sp., Calligonum sp. and Aellinia subpyla. Free-living ants, beetles, lepidoptera, flies, dragonflies, agamid and lacertid lizards. Preferred foods

were lizards and mole-crickets.

Taif Mixed meal (23-25% protein) or poultry pellets (22 or 13% protein) to which eggs, carrots, mealworms (30g per bird per day), bran, mineralsSaudi Arabia and vitamins were added to form a wet paste.

Meade-W aldo 1890

Bede 1928

Mendelssohn et al. 1979] Mendelssohn 1980

Ramadan-Jaradi & Ramadan-Jaradi 1989

Ponomereva 1982

Gaucher e ta l. 1989

Table 2.8 Summary of diets given to captive houbara

( j tCO

60

Bailey (1992) noted that many bustard and stone curlew Burhinus oedicemus

chicks in AI Ain Zoo suffered from deformities associated with too rapid growth

due to excessive protein, possible calcium and phosphorus imbalances and

inadequate exercise. Furley, C.W., Greenwood, A.G. & Solomon, L. (unpubl.)

reported that overfeeding with a high protein diet resulted in obese and

unhealthy birds. They performed post mortems on two houbara which showed

excessive abdominal fat bodies and fatty livers. The intestine of one bird was

completely embedded in semi-necrotic fat, impeding its natural motility.

Anderson (1995) explains the role of micronutrients, such as vitamins, minerals

and amino acids, in the diet of captive bustards. The tendency to simplify

captive diets often results in a limited number of food types compared with wild

diets and therefore specific micronutrients may be lacking.

2.3 Discussion

2.3.1 Relative merits of techniques used to study the diet

A variety of methods have been used to investigate the diet of the houbara, but

all suffer from inherent bias. The simplest way is to interview local people who

are familiar with the houbara, and to catalogue locally available foods (Mian &

Surahio 1983; Mirza 1985; Surahio 1985). However, this only identifies possible

foods and may miss those that are inconspicuous or nocturnal, and gives little

indication of the relative importance of different food items.

Another approach is to observe houbara in the field and calculate a time budget

for different items in the diet (Hinz & Heiss 1989; Launay 1989a, b & c).

However, problems arise when the observer cannot see what the bird is eating

and are most problematic for animal prey. Another disadvantage is that houbara

are very wary and may not behave normally (see Collins 1984). Most

observational data are from semi-captive birds and their behaviour may differ

from wild birds (Table 2.7).

A better approach is to examine gizzard contents, although this necessitates

killing or examining dead birds. However, the diet of the latter may differ from

that of healthy birds if they were weak or sick before they died. Most studies are

based on single houbara (Valverde 1957; Webb & Berthelot 1836-1844;

61

Lavauden 1914; Table 2.6), although a few researchers have obtained gizzards

from hunting expeditions, e.g. Mirza (1971) and Fox (1988).

Examination of faeces is better than other methods because it does not harm

the birds. It also allows repeat sampling from individuals, although

pseudoreplication must be considered in the analysis. Collins (1984,1993) and

Gubin & Mukhina (in prep.) have examined faeces from C.u.fuertaventurae and

C.u.macqueen/respectively. However, partially digested fragments may be

difficult to identify, and easily digested, soft-bodied arthropods and fleshy plant

structures may be underestimated (Collins 1984, 1993; Goriup & Norton 1992;

Gubin & Mukhina, in prep.).

2.3.2 A comparison of the diet of the three houbara subspecies

The taxa recorded as food items for wild houbara are listed in Tables 2.1 to 2.4.

However, I also wanted to use the frequency of citations of foods to indicate the

importance of each taxon and to compare between the subspecies. The

majority of the citations are for C.u.macqueeni, so a system based solely on the

number of citations would underestimate the importance of the foods of

C.u.fuertaventurae and C.u.unduiata. A less biased index was calculated using

the number of taxa recorded for each subspecies, the number of authors who

have recorded the diet for that subspecies and the frequency of citations for

each taxon. This weighted percentage of citations, referred to as the citation

index, was calculated from Tables 2.1 to 2.4 via the following equation:

Citation Index per taxon =

Number of citations for that food taxon x 100(Total citations per subspecies x Total taxa in the table)

Values for the citation index of plant and animal foods are listed in Tables 2.9

and 2.10 respectively.

62

Chlamydotis unduiata fuertaventurae

Chlamydotis unduiata unduiata

Chlamydotis unduiata macqueeni

Total

Fruit, flower, or seed

Green plant Fruit, flower, or seed

Green plant Fruit, flower, or seed

Green plant Fruit, flower

or seed

Greenplant

Plant family No. Index No. Index No. Index No. Index No. Index No. Index No. No.

Aizoaceae 0 0.0 2 1.4 0 0.0 0 0.0 0 0.0 0 0.0 0 2

Anacardiaceae 0 0.0 0 0.0 2 1.0 0 0.0 0 0.0 0 0.0 0 0

Asclepiadaceae 0 0.0 0 0.0 0 0.0 0 0.0 0 0.0 2 0.5 0 2

Capparaceae 0 0.0 0 0.0 0 0.0 0 0.0 3 1.2 5 1.3 3 5

Caryophyllaceae 0 0.0 0 0.0 0 0.0 1 2.4 0 0.0 1 0.3 0 1

Chenopodiaceae 0 0.0 0 0.0 5 2.4 1 2.4 4 1.6 10 2.6 4 10

Cistaceae 0 0.0 0 0.0 1 0.5 0 0 0 0.0 0 0.0 1 0

Compositae 0 0.0 2 1.4 5 2.4 1 2.4 3 1.2 7 1.9 4 10

Cruciferae 2 3.5 4 2.7 3 1.4 0 0.0 1 0.4 12 3.2 3 16

Cyperaceae 0 0.0 0 0.0 0 0.0 0 0.0 0 0.0 2 0.5 0 2

Ephedraceae 0 0.0 0 0.0 0 0.0 0 0.0 0 0.0 1 0.3 0 1

Euphorbiaceae 0 0.0 0 0.0 0 0.0 0 0.0 0 0.0 2 0.5 0 2

Geraniaceae 0 0.0 1 0.7 0 0.0 0 0.0 1 0.4 1 0.3 1 2

Gramineae 4 7.0 1 0.7 3 1.4 2 4.8 6 2.4 13 3.4 12 16

Leguminosae 5 8.8 10 6.8 4 1.9 0 0.0 6 2.4 8 2.1 11 18

Liliaceae 0 0.0 0 0.0 0 0.0 0 0.0 0 0.0 5 1.3 0 5

Moraceae 0 0.0 0 0.0 1 0.5 0 0.0 0 0.0 0 0.0 0 0

Plantaginaceae 0 0.0 1 0.7 0 0.0 0 0.0 0 0.0 2 0.5 0 3

Palmaceae 0 0.0 0 0.0 0 0.0 0 0.0 1 0.4 0 0.0 1 0

Polygonaceae 0 0.0 0 0.0 0 0.0 0 0.0 4 1.6 2 0.5 4 2

Rhamnaceae 0 0.0 0 0.0 1 0.5 0 0.0 6 2.4 0 0.0 6 0

Sapotaceae 0 0.0 0 0.0 1 0.5 0 0.0 0 0.0 0 0.0 0 0

Solanaceae 3 5.3 0 0.0 1 0.5 0 0.0 1 0.4 0 0.0 4 0

Scrophulariaceae 0 0.0 0 0.0 1 0.5 0 0.0 0 0.0 0 0.0 0 0

Tiliaceae 0 0.0 0 0.0 0 0.0 0 0.0 2 0.8 2 0.5 2 2

Umbelliferae 0 0.0 0 0.0 1 0.5 0 0.0 0 0.0 0 0.0 0 0

Zygophyllaceae 0 0.0 0 0.0 2 1.0 0 0.0 3 1.2 12 3.2 3 12

Family unknown 0 0.0 0 0.0 0 0.0 0 0.0 0 0.0 1 0.3 0 1

Total citations 14 24.6 21 14.4 31 15 5 12 41 16.4 88 23.2 59 112

Table 2.9 The number (No.) of citations and citation index (Index) of plant foods for

the three houbara subspecies. The three highest values are shown in bold.

63

Taxonomic Group

Chlamydotis unduiata fuertaventurae

Number of Citation Index citations

Chlamydotis unduiata unduiata


Chlamydotis unduiata macqueeni


Reptiles 7 4.9 11 6.5 18 2.1

Mammals 5 3.5 0 0.0 2 0.2

Total vertebrates 12 8 .3 11 6.5 20 2.4

Lepidoptera 1 0.7 0 0.0 4 0.5

Hemiptera 0 0.0 0 0.0 2 0.2

Orthoptera 3 2.0 3 1.8 18 2.1

Odonata 0 0.0 0 0.0 1 0.1

Isoptera 0 0.0 0 0.0 4 0.5

Diptera 0 0.0 0 0.0 1 0.1

Total Hymenoptera 2 1.4 6 3.6 13 1.6

Apidae 0 0.0 0 0.0 1 0.1

Vespoldea 0 0.0 0 0.0 1 0.1

Ichneumonidae 0 0.0 0 0.0 1 0.1

Formlcldae 2 1.4 6 3.6 10 1.2

Total Coleoptera 11 7.6 13 7.7 77 9.2

Carabidae 0 0.0 0 0.0 8 1.0

Scarabaeidae 5 3.5 2 1.2 12 1.4

Buprestidae 0 0.0 2 1.2 1 0.1

Chrysomelldae 0 0.0 1 0.6 1 0.1

Staphyllnldae 0 0.0 0 0.0 1 0.1

Curculionidae 2 1.4 0 0.0 9 1.1

Tenebrionidae 1 0.7 5 3.0 28 3.3

Meloidae 0 0.0 0 0.0 1 0.1

Dermestidae 0 0.0 0 0.0 1 0.1

Elateridae 0 0.0 0 0.0 2 0.2

Silphidae 0 0.0 0 0.0 1 0.1

Cantharidae 0 0.0 0 0.0 1 0.1

Total Insects 17 11.8 22 13.0 120 14.3

Araneae 0 0.0 2 1.2 2 0.2

Scorplones 0 0.0 1 0.6 1 0.1

Soilfugae 0 0.0 0 0.0 4 0.5

Total arachnids 1 0.7 3 1.8 8 1.0

Crustacea (Isopoda) 0 0.0 0 0.0 3 0.4

Myriapoda(Chllopoda)

0 0.0 0 0.0 2 0.2

Mollusca 8 5.6 2 1.2 1 0.1

Total Invertebrates 26 18.1 25 14.8 133 15.8

Total animal 38 26.4 36 21.3 153 18.2

Table 2.10 The number of citations and citation index for animal foods of the three

houbara subspecies. The highest values are shown in bold.

64

Citation indices for plant foods

The total citations for green plants (112) were higher than for fruits, flowers and

seeds (59), although this was not the case for C.u.unduiata which had 31 citations

for fruits, flowers and seeds, and only 5 for green plants. C.u.macqueeni showed

the highest diversity of plant foods with 18 families eaten as vegetative structures

and 13 families as fruit and flowers. C.u.unduiata had records for four families as

vegetative structures and 14 as fruit and flowers, while C.u.fuertaventurae had

records for seven families as vegetative structures and four families as fruit and

flowers. This probably reflects the higher number of studies carried out on

C.u.macquee/?/particularly compared with C.u.unduiata which is poorly known.

There may be a tendency for C.u.fuertaventurae to eat a narrower range of fruits

and flowers, perhaps influenced by the diversity of plants in its home range.

The families with the highest citation indices for vegetative foods for each three

subspecies were: C.u.fuertaventurae: Leguminosae (6.8), Cruciferae (2.7),

Aizoaceae (1.4) and Compositae (1.4); C.u.unduiata: Caryophyllaceae (2.4),

Chenopodiaceae (2.4), Compositae (2.4) and Gramineae (4.8); C.u.macqueeni:

Cruciferae (3.2), Gramineae (3.4), Zygophyllaceae (3.2) and Chenopodiaceae (2.6)

(see Table 2.9).

The four families with the highest citation indices as seeds, fruit or flowers eaten by

the houbara subspecies were: C.u.fuertaventurae: Gramineae (7.0), Leguminosae

(8.8) Solanaceae (5.3) and Cruciferae (3.5); C.u.unduiata: Chenopodiaceae (2.4),

Compositae (2.4), Leguminosae (1.9), Gramineae (1.4) and Cruciferae (1.4);

C.u.macqueeni: Chenopodiaceae (1.6), Polygonaceae (1.6) Gramineae (2.4),

Leguminosae (2.4) and Rhamnaceae (2.4).

All three subspecies had records for Gramineae, Leguminosae, Cruciferae,

Compositae and Solanaceae (Table 2.9). The Zygophyllaceae and Chenopodiaceae

were important for C.u.unduiata and C.u.macqueeni. Many plant families were

eaten as both vegetative and fruiting or flowering structures.

65

Citation Indices for animal foods

A wide range of animais were consumed by houbara (Table 2.10). invertebrates

were particularly important, with records from four phyla of the Arthropode, most of

which were insects, for which eight orders were recognised. There were fewer

citations for vertebrates than for invertebrates, although reptiles had citations

indices of 4.9, 6.5 and 2.1 for C.u.fuertaventurae, C.u.unduiata and C.u.macqueeni

respectively. Apart from Fox (1988) and Gubin & Mukhina (in prep.), reptile records

were based on feeding observations. However Symens (1987) noted that houbara

were not always successful when hunting lizards, and observation alone may over

estimate their importance. Mammals were only recorded as foods for

C.u.fuertaventurae and C.u.macqueeni (citation indices of 3.5 and 0.2). It may be

difficult to detect vertebrate remains, for although Gubin & Mukhina (in prep.) found

a mouse tail and reptile bones in faeces, Nazarov (1992) was unable to detect

bones in faeces of houbara fed on small birds.

The citation indices suggested that invertebrates formed a consistently high

proportion of the diet for all subspecies {C.u.fuertaventurae 18.1, C.u.unduiata 14.8

and C.u.macqueeni 15.6), and as with plants, a high diversity of animal prey were

recorded for C.u.macqueeni. Beetles were the most important insect prey in terms

of diversity and number of records and had similar citation indices for

C.u.fuertaventurae, C.u.unduiata and C.u.macqueeni {7.6, 7.7 and 9.2 respectively),

with records from 12 beetle families for C.u.macqueeni. Tenebrionids were

important for C.u.unduiata and C.u.macqueeni, but were rarely recorded for

C.u.fuertaventurae (citation indices of 3.0, 3.3 and 0.7 respectively). However, this

was reversed for Scarabaeidae which had a citation index of 3.5 for

C.u.fuertaventurae, compared with 1.2 for C.u.unduiata and 1.4 for C.u.macqueeni.

Only C.u.fuertaventurae had a high citation index for molluscs (5.6) based on snails,

although more recent work has not confirmed that houbara eat snails (Collins 1984).

There may be differences in the food preferences of the subspecies, influenced by

an impoverished fauna and flora for the island-dwelling C.u.fuertaventurae

compared with mainland dwelling houbara (MacArthur & Wilson 1967). For

example, dung-beetles are more likely to reach the Canaries than apterous

tenebrionids. Ants were also frequently cited for the three subspecies

{C.u.fuertaventurae 1.4, C.u.unduiata 3.6 and C.u.macqueeni 1.2), and the citation

66

indices for Orthoptera were fairly consistent across the range {C.u.fuertaventurae

2.1, C.u.unduiata 1.8 and C.u.macqueeni2.^).

2.3.3 Seasonal trends in the houbara’s diet

Several authors have commented on the seasonal consumption of food types but

their evidence is often based on an interpretation of what they supposed were

abundant foods at the time. VVork by Collins (1984,1993) and Gubin & Mukhina (in

prep.) is more detailed, although their results were biased towards male birds.

Seasonal consumption of plant foods

Collins (1984,1993) states that C.u.fuertaventurae tavouxed Lycium sp. berries in

April. Faeces from one bird consisted almost entirely of Lycium sp. and the bird had

apparently ignored other abundant foods, such as herbaceous plants. Gillett (1988)

suggested that fresh plant growth, seedlings, fruits and flowers were selected by

C.u.unduiata following rain in the winter and spring.

Other work has suggested that the consumption of plants by houbara is

opportunistic. Roberts (1991) mentioned that C.u.macqueeni gizzards contained

perennials in the early winter and herbs in spring. Birds in semi-natural conditions

were also thought to respond to seasonal changes in vegetation (Launay 1989c;

Anegay 1992; Symens 1987) and to consume the vegetative parts of shrubs during

the winter but new growth of annual plants in the spring.

Gubin & Mukhina (in prep.) related the remains of food in faeces to qualitative

descriptions of plant phenology in Kazakhstan. Grasses, Saisoia sp. and tulips

made up much of the spring diet, but by the end of March the amount of plant

material in faeces decreased. At the end of May and the start of summer, seeds

were eaten but the mean proportion of vegetative plant material dropped to about

10%. By June Erodium sp. seeds constituted up to 10% of the volume of some

samples, and by the end of June most ephemeral plants had dried up and there

were more seeds than vegetative plant parts in the faeces. In September, only a

small amount of seeds and vegetation was present in faeces.

67

Seasonal consumption of animal foods

Invertebrates are frequently said to be seasonally important in the diet.

C.u.fuertaventurae appeared to eat tenebrionids in preference to ants, because

while ants were available all year round they were only consumed in the summer

when tenebrionids were rare (Collins 1984,1993). Mirza’s (1971) account of

C.u.macqueenig\zzards suggested an increase in invertebrate consumption

between early and late winter, when houbara may have selected high protein foods

prior to the breeding season. Consumption of insects by houbara in semi-natural

conditions was thought to reflect seasonal abundance (although this was not

measured) with more insects eaten in the winter than in the spring (Launay 1989c,

Symens 1987). Insects were said to be very important for young chicks (Launay &

Paillat 1990) and the hatching of chicks in Kazakhstan may be related to an

increase in invertebrate abundance (F. Launay pers. comm.). Houbara gizzards

from Mahazat as-Sayd suggest a shift towards invertebrate foods in the autumn and

plant foods in the spring (Combreau & Rambaud 1995).

Gubin & Mukhina (in prep.) related a description of the seasonal abundance of

animals to prey remains in faeces. Animals were scarce in early spring but small

amounts of ants, beetles (Tenebrionidae, Curculionidae; Carabidae and

Scarabaeidae), woodlice, Myriapoda and spiders were found in faeces. By the end

of March, the volume of animal remains in faeces and gizzards (n=5) increased to

20% with Curculionidae and Tenebrionidae making-up 12% of the volume of faeces.

Termites, ants, Elateridae and Cicindelidae were also eaten. At the beginning of

May, the volume of animal matter in the faeces continued to increase and 40% with

of the volume of faeces consisted of tenebrionid and buprestid remains.

Curculionidae, Scarabaeidae, Meloidae and Solifugidae were also eaten, but

although Meloidae were very abundant they rarely occurred in faeces probably

because of their high toxicity. By the end of May and the start of June, tenebrionid

and buprestid remains formed up to 70% of the volume of faeces. From mid-June

Solifugidae occurred in 70% of samples and made up 10% of the volume of faeces,

and would have formed a high volume of gizzard contents. Orthoptera were found in

faeces from June onwards and lizards occurred in 9.2% of samples. Woodlice were

said to have been present at all times but were only found faeces in September

when other prey were scarce. Beetles, Solifugidae and a single lizard and mouse

were also eaten at this time.

68

Reports of faeces and gizzards dominated by a single invertebrate species are

common, particularly ants (Goriup & Norton 1992; Glutz von Blotzheim etal. 1973)

and locusts or grasshoppers (see Table 2.5), and Symens’ (1988a) observations in

Saudi Arabia suggest that houbara actively respond to locust swarms. In Central

Asia, Kostin (1956) mentioned gizzards that only contained tenebrionid beetles,

while Salikhbaev & Ostapenko (1967) reported gizzards containing 400-500

termites. Social insects, such as ants and termites, provide an abundant prey for

houbara especially during the dispersal phase of their reproductive castes, and also

if their foraging trails or nests are exploited.

2.3.4 Implications for the management of habitat and captive birds

Evidence to date suggests that the houbara is an omnivore, consuming a wide

variety of prey. The most frequently cited foods were invertebrates, especially

tenebrionid beetles, Orthoptera and ants, and green plants including native species

and cultivated crops. There were few records of vertebrate prey. Differences

between the subspecies probably reflect the local availability of food in their ranges.

Some data suggested preferences for particular food types and seasonal changes

in food consumption with animal foods becoming more important prior to the

breeding season. However, apart from Collins (1984, 1993), no attempts were made

to measure food availability.

There remains much basic information to be learnt about the houbara. However,

current attempts to release captive-bred birds into the wild (Bailey & Hornby 1994;

Biquand etal. 1992) cannot succeed unless suitable habitats are available. It may

be important to try to manage reserves so that sufficient food is available to cover

seasonal trends and stressful times of year, such as extreme dry, hot or cold

periods, which occur in many parts of the houbara's range. Crops such as chick

peas, beans, alfalfa, sorghum and brassicas provide an easily grown source of

cover in open areas with little natural vegetation, and are a source of plant and

animal food. In the Canary Islands, a reward scheme operates for farmers which

ensures that alfalfa is cultivated for the benefit of wild houbara (F. Dominguez

Casanova pers. comm.). Alfalfa is also planted in aviaries and at NARC houbara

often hunt grasshoppers in alfalfa plots (A. Owen pers. comm.). Naturally occurring

foods such as favoured plants should be encouraged, since good quality vegetation

69

will also aid invertebrate and small vertebrate populations. The control of grazing by

domestic stock may be an important factor (Oatham 1996). At Harrat Al-Harrah, the

native Capparis spinosa is thought to be very attractive to houbara (P. Seddon pers.

comm.) and attempts to grow this plant, such as seeding suitable habitat, could

improve the quality of over-wintering areas for wild houbara. It could also be grown

in aviaries and on protected release sites for captive bred birds. It does not occur in

UAE, and an analysis of wild houbara diet in UAE will help to identify other locally

occurring food plants that could be used in similar manner.

Ants are a frequent component of the diet and scavenging species are attracted into

aviaries. Rather than being seen as a threat to captive houbara, they are either

innocuous or a possible alternative food for the birds, and chemical control of ants is

not normally necessary.

2.4 Conclusion

Much of the information on the diet of the houbara is observational and there is a

need for a standardised technique based on faecal analysis to study the diet across

the range (see Chapter 5). The relative importance of foods must be assessed in a

non-subjective method and information is needed on the differential digestion of

prey and passage time in order to interpret samples. In addition, studies of the diet

should incorporate a measure of food availability (see Cooper & Whitmore 1990).

70

C h a p t e r 3

P il o t s t u d ie s f o r m o n it o r in g d e s e r t in v e r t e b r a t e s


This chapter assesses various sampling methods for examining the distribution,

abundance and diversity of desert invertebrates (to be used in Chapter 4). Both

aerial insects and ground-dwelling arthropods were sampled, although emphasis

was placed on the taxa most likely to occur in Abu Dhabi (see Chapter 1 ; Tigar

1996a; Appendix 1.1) and to be potential food for houbara. Therefore the

Tenebrionidae, Formicidae and Orthoptera were of particular interest as suggested

in Chapter 2. The aim was not to test the absolute sampling powers of the

techniques, but to identify methods that were reliable and practical within a desert

terrain.

71

3.1 General introduction

Invertebrates can be sampled by a variety of methods from casual observation to

more accurate quantified approaches using complex trapping apparatus

(Southwood 1978; Upton 1991). Composition and size of trap catches are

determined by the biology and behaviour of the taxa being sampled, trap design and

local environmental conditions (see Dent & Walton 1997; Muirhead-Thompson

1991). The best techniques achieve a reliable and representative sample which can

be used as a relative measure for comparison between samples obtained in a

similar fashion. Catches are not usually considered absolute measures of

abundance but rather indices of abundance and activity of the population. For

vertebrate predators, like the houbara, such methods can give an idea of prey

availability (Cooper & Whitmore 1990; Wolda 1990). Studies of avian food supply

must be accurate, as well as appropriate to behaviour of the bird (Hutto 1990).

The severe climate and difficult terrain pose a challenge to biological surveys in

UAE (see Chapter 1). In addition, the areas frequented by houbara are used by

herdsmen, livestock, military personnel and for general recreation. Therefore

equipment should be unobtrusive, robust and only left unattended for a short time.

3.2 Pitfall trapping

3.2.1 Introduction to pitfall trials

Knowledge of Abu Dhabi's invertebrates is biased towards relatively mesic

environments (see Tigar 1996a & b; Appendices 1.1 & 1.2) and surface-active,

desert arthropods have largely been ignored. However, in many arid zones they

form a major proportion of the fauna and the bulk of animal biomass (Crawford

1991; Ghabbour & Shakir 1980; Thomas 1979). Pitfall traps catch ground-dwelling

invertebrates and have been used extensively to compare faunal assemblages,

including those of deserts (e.g. Ahearn 1971; Aldryhim etal. 1992; Ayal & MerkI

1994; Faragalla & Adam 1985; Wharton & Seely 1981).

In November 1992, two separate lines of 30 pitfall traps (one pint plastic tumblers)

with ten paces (about 10m) between each trap were set up and left overnight. Upon

collection 75% (± 0.07 S.D.) of traps contained invertebrates, especially ants.

72

silverfish, tenebrionids and spiders (in 70% ± 0.35, 7% ± <0.01, 15% ±0.12 and 5%

± 0.02 of traps respectively). This indicated that pitfall traps were a useful technique

for sampling invertebrates in UAE.

In order to standardise the trapping procedure, several trial transects were set-up.

These examined the effect of the length of the transect and the time of trapping on

the number and diversity of arthropods captured. To reduce the chance of escapees

and to improve pitfall trap efficiency a dry film of Polytetraethylene-fluoride (“fluon”

manufactured by ICI PLC) was painted around the rim of pitfall cups to create a

non-stick barrier.

3.2.2 Methods

The trapping-time trial

Three transects were sited about 1km from each other across uniform sandy desert

in the Public Hunting Triangle to examine how the number of species (a measure of

diversity) and total number of arthropods captured by pitfall traps varied with time.

Each transect consisted of 30 pitfall traps, spaced ten paces apart and left in place

for 14, 24 or 36 hours from the start time (16.30 hrs). Catches were recorded to

taxonomic order.

The transect length trial

To estimate the optimum number of traps to use in a transect, three separate lines

of 60 pitfall traps were set up across uniform sandy desert and left overnight (16 hr

± 0.5 S.D.). Sixty traps represented the maximum number that could practically be

used in field studies. A Monte Carlo method was used to simulate the effect of using

fewer than 60 traps; n traps (where 0<n<60) were selected at random with

replacement on 50 occasions and the average and standard deviation of the catch

were calculated. Catches were examined in terms of the abundance and species

diversity of total arthropods, and of two groups thought to be important foods for the

houbara: Coleoptera and Hymenoptera.

73

3.2.3 Results

The trapping-time trial

The total trap catches at 14 and 24 hours were similar (71 and 69 arthropods

respectively) (see Table 3.1). However, there was a higher catch at 36 hours (216)

because of the increased number of Hymenoptera, especially ants, in the traps.

Taxa Line 1 (14 hrs) Line 2 (24 hrs) Line 3 (32 hrs)Total caught

Coleoptera 2 2 3Hymenoptera 62 60 193Hemiptera 2 0 0Araneae 2 0 1Thysanura 2 3 18Orthoptera 1 4 0Scorplones 0 0 1Total invertebrates 71 69 216

Total caught per hourColeoptera 0.005 0.003 0.003Hymenoptera 0.148 0.083 0.201Hemiptera 0.005 0 0Araneae 0.005 0 0.001Thysanura 0.005 0.004 0.019Orthoptera 0.002 0.006 0Scorplones 0 0 0.001Mean invertebrate capture 5.07 2.88 6

Number of species caughtColeoptera 2 2 3Hymenoptera 23 15 27Hemiptera 2 0 0Araneae 2 0 1Thysanura 2 2 2Orthoptera 1 4 0Scorplones 0 0 1Total invertebrates 32 23 32

Number of species caught per hourColeoptera 0.143 0.083 0.094Hymenoptera 1.643 0.625 0.844Hemiptera 0.143 0.000 0.000Araneae 0.143 0.000 0.031Thysanura 0.143 0.083 0.056Orthoptera 0.071 0.167 0.000Scorplones 0.000 0.000 0.031Total invertebrates 2.286 0.958 0.889

Table 3.1 Numbers of invertebrates and species caught by three pitfall transects in

place for 14, 24 and 32 hours.

74

The mean catch of total arthropods per hour decreased from 5.07 to 2.88 per hour

between 14 and 24 hours, with a slight increase to 6.00 arthropods per hour at 36

hours. Again, the increase in the total invertebrates caught per hour could be

attributed to higher catches of Hymenoptera, although Thysanura also increased.

However, mean catches of Coleoptera, Hemiptera and Orthoptera decreased

between 14 and 32 hours trapping, while scorpions were only caught in traps left in

place for 36 hours.

Results for the number of species caught per hour were mixed. A total of 32 species

were captured following both 14 and 32 hours of trapping, while only 23 species

were caught for the pitfall transect in place for 24 hours (Table 3.1). The mean

number of species caught per hour was higher following 14 hours of trapping (2.3)

than 36 hours (0.9).

The transect length trial

The random simulations of the mean number of total invertebrates, of Coleoptera

and of Hymenoptera caught with increasing number of traps varied between the

three lines and by taxonomic group, although line 1 had a consistently higher catch

(see Figure 3.1). Note that in all cases, the mean catches of fewer than ten traps

were extremely unstable. However, the overall means showed improved stability

between ten and 20 traps, although the estimate for Hymenoptera in line 3

continued to show some instability, even at 60 traps.

The standard deviations calculated during the simulations were not plotted in Figure

3.1 to avoid confusion caused by the considerable overlap between the three lines.

However, a typical example is given in Figure 3.2 for Coleoptera in line 1, showing

the decline in variance with increasing number of traps. Therefore both the means

and standard deviations of total arthropods, Coleoptera and Hymenoptera had a

tendency towards increased stability with at least ten traps.

75

12 T

10 -Sn0)CI 8 - -

oa>nE3CC

ss

A-A'A'A 'A.A'A’A .A ..,A *A i

4 -

2 - -■

200 10 30 40 50 60

— ♦— Line 1

— ■— line 2— A— Line 3

Number of traps

10 20 30 40

Number of traps

— I—

50

— ♦— Line 1

— ■— Line 2

— A— Line 3

60

12 T

« 10o

| sX

0 61I 4 +cc(00) pS

0

■A-A.^-A-A-a .^

10 20 30 40

Number of traps

50

— ♦— Line 1

— ■— Line 2— A— Line 3

■■IH60

Figure 3.1 Overall mean catch of total invertebrates, Coleoptera and Hymenoptera

caught against number of traps, following 50 random simulations of trap catch.

76

3.5

I 2.5

0 ^1 1.5

I '5 0.50)S n

-0.50 10 20 30 40 50 60

Number of traps

Figure 3.2 The overall mean catch of beetles for line 1 against number of traps.

Error bars are standard deviation about the mean.

Species-effort curve

The cumulative number of species caught for each of the three lines was plotted

and fitted with a logarithmic trend-line to examine the effect of increasing effort (i.e.

number of pitfall traps) on the number of species captured (Figure 3.3). Line 1

captured the highest number of species (24), while lines 2 and 3 both contained 16

species. However, all three lines showed a similar trend, with a decreasing rate of

return for new species typical of species-effort curves.

To investigate the effect further, the angle of inflection was drawn onto each of the

fitted curves by eye (Figure 3.3). This suggested that the rate of return, or the

chance of capturing new species, declined rapidly with more than nine or 12 pitfall

traps. Although new species were still encountered, the proportion of effort required

to encounter new species was much greater.

77

Line 1

« 20 - -

0 10 20 30 40 50 60

Number of traps

Line 2

« 18 T

w 14 --

° 12 - -

■■■■

0 10 20 30 40 50 60

Number of traps

Line 3

« 16 T

% 14 --

12 - -

20 50 600 10 30 40

Number of traps

Figure 3.3 The cumulative number of species caught along three lines of 60 pitfall

traps. The thin solid lines are fitted logarithmic trends. The dashed lines indicate

the point of inflection of the curve and its intersection with the x axis.

78

3.2.4 Discussion

The total number of arthropods caught in the pitfall transects increased between 14

and 36 hours. However, the taxa of most relevance to the houbara, particularly the

large Coleoptera, did not increase during this time, nor did they increase between

14 and 24 hours. The increased catch was the result of an increased abundance of

ants, which are social insects and communicate via a complex system of

pheromones (Holldobler & Wilson 1990), making it is difficult to interpret their trap

catches. These insects generally find food along communal foraging trails, so if a

foraging trail was intersected by a pitfall transect there would be a high probability of

catching high numbers of ants. In addition, some ants are predators and general

scavengers on other arthropods, and would be attracted to contents of the traps,

particularly dead or dying insects. If a trap is left in place for a long time, especially

during the heat of the day, it would contain a higher proportion of dead to live

insects than a trap in place for a shorter time, and would therefore attract more

scavengers.

In general, an increase in sampling time (effort) would be expected to capture more

individuals and more species, but results suggested that this did not occur in the

short-term (i.e. within a few days) (Table 3.1). Rarer species are less likely to be

captured simply because they are less abundant. However, they are also less likely

to be encountered and eaten by a bird, such as the houbara. Therefore for the

current study, an overnight “snap-shot”, obtained using dusk till dawn trapping

would provide a standardised and practical sampling method, and give a relative

measure of arthropod abundance and diversity for comparison across sites. In

addition, it will sample the time periods when houbara are most likely to be foraging

(Anegay 1994; Combreau & Launay 1996).

Sixty traps were used as an experimental maximum. However, the simulation

suggested that while the use of fewer than ten traps gave an unstable impression of

the catch, the total trap catch became stabilised around 20 traps (Figures 3.1 &

3.2). There was still some instability in the number of Hymenoptera (mainly ants)

caught in line three reflecting the colonial biology and foraging behaviour of ants.

Other factors, such as differences in micro-climate between the sites, as well as ant

colony size and species identity may also have affected the number of ants caught

(see MacKay 1991).

79

The species-effort curve (Figure 3.3) suggested that the rate of return of finding

new species declined markedly after 12 pitfall traps. If 20 traps were used, the most

abundant ground-dwelling arthropods would be sampled, although rarer species

might occasionally be missed. However, the use of temporal and spatial replication

would reduce biases and inconsistencies.

Few scorpions were caught in pitfall traps probably because and some species

detect and avoid traps (Polis 1990b). The scorpions caught in pitfall traps are more

likely to be juveniles or smaller species, which have a higher probability of being

captured and a lower probability of escaping than larger individuals. A short-

wavelength UV light could also be used at night to give an estimate of scorpion

population density (Polis 1990a).

Climate and micro-climate are also likely to influence the size and composition of

pitfall trap catches (see Ahearn 1971). These factors cannot be controlled during

the trapping, but can be monitored using a datalogger.

Other factors to be considered when using live pitfall trapping are losses due to

escapees and predation. However, these would occur with equal probability at all

trap sites. One solution is to use liquid preservatives or killing agents in pitfall traps,

although these have attractant or repellent effects upon certain taxa (see Luff 1968,

1975; Wagge 1985). Preserving fluids are usually used if traps are in situ ior a long

time, while initial tests in UAE suggested that overnight, unbaited traps captured

many ground-dwelling invertebrates. Difficulties in transporting liquids over rough

terrain, combined with evaporation and wind-blown sand filling the traps made the

use of a preservative a less viable option. In addition, it might be difficult to relocate

traps on sandy substrates after a long period of time judging from the poor recovery

of the much larger boards (see Section 3.3). In Saudi Arabia, Combreau &

Rambaud (1995) used dilute picric acid in monthly pitfall traps and their catches

included gerbils and muscarid fly larvae. The latter were presumably breeding on

the decaying trap contents, and are not relevant to the present study.

Another advantage of live trapping is that common and easily identified species can

be released, thereby reducing the effect of removing them from their environment.

Furthermore, the pilot trials revealed the most westerly record for the gecko

80

Teratoscincus scincus (Osborne 1993). Reptiles are also recorded as being preyed

upon by the houbara, and it is useful to have an idea of their distribution.

3.3 The use of refuge boards

3.3.1 Introduction

Some ground-dwelling arthropods, including beetles, scorpions, solifugids and

spiders, seek refuge under pieces of debris and wood in the desert (Muma 1980).

The use of standard-sized, artificial refuges might provide a way of sampling these

invertebrates.

3.3.2 Methods

To test the viability of refuges and the effect of their size on capture, 40 rectangular

wooden boards were made with the following dimensions: 30 x 30 cm (n=20), 30 x

60 cm (n=10) and 60 x 60 cm (n=10). Boards were distributed at random and at

least 250m apart across a sandy habitat, dominated by two grasses: Pennisetum

divisum and Panicum turgidum. The boards were located on 16* May 1993 and

their position was recorded using a Magellan GPS (Global Positioning System) unit

(accurate to 100m) which was used to relocate them 28 days later.

3.3.3 Results

Only 57% of the boards were recovered and 35% of those found harboured a small

number of invertebrates, including termites, spiders and thysanurans (Table 3.2). A

few tracks of larger tenebrionids and reptiles were seen under the boards, but the

individuals responsible for the tracks were not present. The largest boards were

easier to find than the smaller boards, and also acted as better refuges or were

colonised more quickly. However, the effect of size could not be tested statistically

because of the low recovery rate.

81

30 X 30 cm (n=20)

Size of board30 X 60 cm

(n=10)60 X 60 cm

(n=10)Mean value

Recovered and used as refuge (%) 5 20 40 22

Recovered but unoccupied (%) 45 40 20 35

Missing (%) 50 40 40 43

Table 3.2 Percentage recovery of refuge boards after 28 days in the desert.

3.3.4 Discussion

Just over half the boards were recovered and those that were harboured few

invertebrates, which represented taxa caught in higher numbers by pitfall traps.

Perhaps refuges need to be present for a long time before they are suitable for

colonisation, and require changes caused by weathering and the activity of termites

and other detritivores which alter soil chemistry and structure (Nutting etal. 1987).

A factor influencing the low recovery rate of boards was the difficulty in driving

slowly on soft sand. This made it difficult to use the navigational function of the

GPS, which relies on changes in position for accurate route determination.

Searching on foot helped to locate some boards, many of which were partially

hidden by sand suggesting that others may have been buried.

The overall performance of the boards was disappointing and there appeared to be

little potential in developing a quantified method based upon their use. However,

similar wooden boards and other man-made debris are often found in Abu Dhabi

especially near old bedu encampments, and could provide a further source of

invertebrate and vertebrate records.

3.4 Sweep-netting and beating trays

3.4.1 Introduction and methods

Sweep-nets and beating trays remove invertebrates from vegetation. Primarily

herbivorous insects and nectar or pollen feeders are caught, but their predators

including spiders, mantids and wasps, and even scorpions may also occur (T.

82

Benton, pars. comm.). Sweep-netting is probably the most widely-used method of

measuring invertebrate availability for avian predators, mainly because it is easy

and cheap, although it is biased towards sedentary invertebrates and is sensitive to

changes in vegetation structure, and climatic conditions when sampling (Cooper &

Whitmore 1990). It can be used semi-quantitatively by sweeping or beating for a

specified distance, number of passes of the net, distance or time (e.g. Savory 1974:

Green 1984; Rebel etal. 1995).

In September 1993 sweep-netting was attempted at two locations which had

Zygophyiium sp. - Haloxylon salicornicum plant associations (see definition in

Roshier etal. 1996). The net was passed ten times across the vegetation wherever

it occurred, once every ten paces (approximately 10m), along a 200m line. A total of

12 lines were sampled. All insects captured were removed from the net using a

pooter and recorded. The beating tray was used along 12 transects, which were

parallel to and 20m away from the sweep-net transects. Ten sharp taps to the

vegetation were executed with a thick bamboo cane to loosen any insects.

3.4.2 Results

Very few invertebrates of limited taxa were caught in the sweep-nets (Table 3.3).

Numbers caught were variable (note that standard deviation was twice the mean

value per transect). No insects were captured using the beating trays.

Site Replicate Taxa Number caughtPHT 1 0PHT 2 Hemiptera 3PHT 3 0PHT 4 0PHT 5 0PHT 6 0

B 1 0B 2 0B 3 0B 4 Tentyrina palmeri (Tenebrionidae) 1B 5 0B 6 Crematogaster antaris (Formicidae) 2

Total insects caughtMean insects per transect (±SD)

60.5 (±1.0)

Table 3.3 Number of invertebrates and taxa caught along twelve 200 m Sweep-net

transects. (PHT = Public Hunting Triangle, B = Baynunah).

83

3.4.3 Discussion

Very few insects were caught by sweep-netting and none was caught by the beating

tray. Both methods were difficult to carry out because the vegetation was sparse

(typically <5% cover; Roshier et al. 1996) and consisted of characteristic desert

plants with spiny or twiggy growth. The net frequently became entangled in the

vegetation, and gusty winds made it difficult to control the net and to remove the

catch. Most shrubs were too low and spiny to accommodate the beating tray.

Automated sampling methods, such as D-vacs or suction traps, might be useful.

However, these methods, as well as sweep-netting and beating, are sensitive to the

daily temperature variations that typically occur in Abu Dhabi (see Chapter 1), which

affect insect activity and hence capture rate. In addition, heavy equipment would be

difficult to handle on the sandy, uneven terrain, and suction or vacuum apparatus

would probably fill up and be damaged by dust and sand.

Beating trays and sweep-nets could be used to collect specimens after the rainy

season, but they cannot be recommended as methods for regular sampling.

However, herbivorous insects would be better sampled as winged adults using a

light trap (see Heath trap below), although some apterous insects, like certain

weevil species, may remain difficult to sample.

3.5 Walking transects for Orthoptera


In September 1993 Line and band transects are used to assess the abundance of

locusts and other Orthoptera (M. Richie pers. comm.). Twelve transects were

attempted by walking in a straight line for approximately 200m, and recording any

Orthoptera along a 5m wide band.

3.5.2 Results

No Orthoptera were encountered along any of the transects.

84

3.5.3 Discussion

Again, the low vegetation cover meant that this technique is not normally applicable

in Abu Dhabi. However, such transects may be of value when Orthoptera are

seasonally abundant, e.g. following the rains, although identification to species level

may be difficult in the field. Some Orthoptera could be captured using a light trap

(see Section 3.7).

3.6 Flight Interception traps


Flight interception traps were considered as a sampling method for flying insects

(see for example Owen 1993). A Malaise trap was positioned on a sandy site at

Sweihan Research Station to look at the types and numbers of flying insects

caught. The reservoir of the trap was filled with 70% ethanol and left in place for 28

days.

3.6.2 Results

The Malaise trap caught a total of 288 insects. However, most were houseflies

(>51%) or small Hymenoptera (38%) with fewer Coleoptera (5%), Lepidoptera

(4.9%) and Neuroptera (<0.2%) (Table 3.4). The average daily catch was 10.3

insects. Some taxa were difficult to identify owing to the lack of taxonomic keys for

the region.

3.6.3 Discussion

The Malaise trap captured flying insects which were not captured in the pitfall traps.

However, daily trap catches were low, about ten to 100 times less than a single

night's catch from a Heath light trap in the same area (see Section 3.7 below).

Houseflies and small Hymenoptera dominated the Malaise trap catch, although

these traps typically capture large Hymenoptera, adult Lepidoptera and only some

Diptera (Cooper & Whitmore 1990). The Abu Dhabi catch contained few likely food

sources for houbara (see Chapter 2).

85

Order Family Species Number caught

Coleoptera Buprestldae Chrysobothhs parvipunctata 1

Bostrlchldae Sinoxylon sengalensis Karsh 1

Elaterldae Heteroderes sp. 4

Tenebrionidae Cyphostethe nr saharensis Chob. 9

Hymenoptera Formicidae unknown 9

Sphecldae Bembix sp. 1

Sphecldae unknown 3

Scollldae Campsomeriella thoracica Fab. 2

Scollldae unknown 2

Mutlllldae unknown 3

Sphecldae unknown 90

Lepidoptera Noctuldae unknown 14

Neuroptera Myrmeleonldae unknown 1

Diptera Muscldae Musca domestica Linnaeus 148

Total insects 288

Mean daily catch of insects 10.29

Mean daily catch of M. domestica 5.2

Table 3.4 Insects caught by a Malaise trap at Sweihan Research Station.

(Determinations by J. Boorman, Natural History Museum, London.)

Malaise traps are usually sited in a permanent position, and used to give a monthly

or weekly catch. It would be difficult to find any suitably protected sites (away from

the disturbance of humans or camels) in UAE and Sweihan is not close to areas

where houbara over-winter. However, when sited in a well-vegetated aviary at AI Ain

Zoo, the same trap caught over a million insects of spectacular diversity (especially

Hymenoptera and Diptera) during 30 days (Warren, S. & Tigar, B. unpublished

data). This suggests that flying insects are scarce in desert areas, probably

because of their patchy and stochastic nature, combined with low plant cover. For

practical reasons, the Malaise trap also presented problems because it was highly

conspicuous and difficult to erect on soft sand, making it relatively unstable. Its

ability to sample appropriate taxa for houbara prey appears doubtful, and the

insects sampled are caught in higher numbers by a Heath trap.

86

3.7 The use of light traps for the capture of nocturnal insects.

A Heath trap (supplied by Watkins and Doncaster) was tested during September

1993 at Sweihan. Initially it was filled with egg boxes to act as landing/roosting

places for flying insects attracted into the trap at the night. However, the next

morning the trap quickly heated up and most of the catch, consisting of over several

hundred insects, escaped. Therefore, a jar of ethanol was placed under the funnel,

to kill any insects entering the trap, but it also removed lepidopteran scales making

these insects hard to identify. Instead, a large jar lined with plaster of Paris was

placed under the funnel, and 15 ml of ethylene dichloride was dispensed into the

plaster when setting up the trap. Ethylene dichloride is a killing agent with a low

vapour pressure, and therefore a relatively slow evaporation rate. Upon collection

the next day about 5 ml of ethyl acetate was added to the jar to ensure that all the

material died rapidly. A final refinement was a photoelectric sensor which

automatically switched the trap on or off according to the light level, helping to

conserve battery power.

The light trap caught many flying insects not sampled by pitfall traps, including

Lepidoptera, Coleoptera (especially Scarabaeoidea), Orthoptera, Diptera,

Myrmeleonidae and Hemiptera. Only a single Heath trap was available. Ideally traps

should be replicated to give a measure of variance, but a single trap could be used

to give an indication of the relative abundance of flying insects at each site each

month.

3.8 General discussion and recommendations for trapping methods

No single method can be expected to sample the entire arthropod fauna, since each

trap is designed to exploit particular traits of its intended catch. The pitfall traps

proved an efficient method for sampling ground-dwelling invertebrates in UAE,

particularly the Tenebrionidae which are frequently cited in as a food item for

houbara (see Chapter 2). Herbivorous insects, such as grasshoppers and locusts

(Orthoptera), weevils (ColeopteraiCurculionidae) and lepidopteran larvae are

unlikely to be captured in pitfalls. However, the Heath light trap captured some of

these taxa, including Orthoptera, apterous weevils and adult Lepidoptera.

Therefore, the combination of pitfall traps and a Heath trap can be used to sample

the available ground-dwelling and flying invertebrates (Chapter 4).

87

The other methods tested (refuge boards, sweep-nets, beating trays, grasshopper

transects, and a Malaise trap) either yielded little information or were impracticable.

However, along with hand-searching on vegetation and under rocks, they could be

used to provide additional information on invertebrate diversity and abundance

following seasonal rains.

88

C h a p t e r 4

T h e d iv e r s it y a n d a b u n d a n c e o f in v e r t e b r a t e s in A b u D h a b i's d e s e r t s


There is scant information on invertebrates in Abu Dhabi (see Tigar 1996a & b;

Collingwood etal. 1997; Chapter 1 & Chapter 3). Therefore base-line data on desert

invertebrates were gathered and examined for general patterns of abundance and

diversity. These aims were achieved through a two-year monitoring programme

using methods evaluated through pilot studies (Chapter 3). Ground-dwelling

invertebrates were sampled with overnight pitfall traps and flying insects with a

Heath light trap. The effect of climate, micro-climate, substrate and the phase of the

moon on trap catch were investigated.

The study established a database and a reference collection of invertebrates for the

UAE, in collaboration with a network of international taxonomists. These resources

facilitated the identification of houbara prey in Chapter 5 and will aid further

entomological and biogeographical research. A list of animals encountered during

the study is given in Appendix 4.1, including 196 new invertebrate records for Abu

Dhabi and ten new species (Collingwood & Agosti 1996).

89

4.1 Patterns of abundance and diversity of ground dwelling arthropods

(Section 4.1 has been published as: Tigar, B. J. & Osborne, P. E. (1997). Patterns

of arthropod abundance and diversity in an Arabian desert. Ecography 20\ 550-

558.)

4.1.1 Introduction

Biodiversity is probably spatially heterogeneous in most ecosystems (Gaston &

Williams 1996). Although desert landscapes appear monotonous and uniform, they

can exhibit patchiness at scales from a few centimetres through to whole continents

due to differences in microclimate, habitat and geography (e.g., Crawford 1988).

Temporal variability may also be marked, occurring on a daily, seasonal, yearly or

historical basis (Crawford 1991) and environmental factors affecting deserts are

also conspicuously stochastic. For example, rainfall is sporadic and variable, and

the total annual precipitation can fall in a single event (e.g. Bottomley 1996 for Abu

Dhabi). Understanding the abiotic and biotic processes that affect species

composition in space and time is an important aspect of community ecology of

deserts (Polis 1991a).

Large-scale studies of biodiversity are scarce, especially outside North America,

Australia and Africa (Gaston & Williams 1996). For deserts, they are even scarcer

and, in Arabia, ecological studies are relatively recent (Osborne 1996c) and basic

knowledge of species' occurrences is poor. Satchell (1978) was among the first to

describe the ecology of the United Arab Emirates and to list some of its

invertebrates (since updated by Tigar 1996a). Faragalla & Adam (1985) and

Aldryhim etal. (1992) have studied the Coleoptera in neighbouring Saudi Arabia.

Ayal & MerkI (1994) studied tenebrionid beetles in the Negev Desert of Israel but

this has a Mediterranean rather than an Arabian influence.

This chapter explores the spatial and temporal patterns in arthropod taxonomic

diversity resulting from a two year monitoring programme. The results show

seasonal (cyclical) changes in numbers and differences between sites related to

climatic factors. In particular, arthropods at near-coastal sites appeared to benefit

from high humidity, allowing a larger number of taxa to occur and to remain active

through the oppressive heat of summer.

90

4.1.2 Methods

Trapping sites

Five sites were established for monitoring invertebrates in separate geographic

areas where houbara or their tracks had been recently recorded (Osborne 1992):

Baynunah, Medinet Zayed, Public Hunting Triangle, Um Az Zimul and Khatam (see

Plates 4.1-4.5, Figure 1.1 & Table 4.1). These areas consisted of mobile sand

dunes intersected by compacted gravel plains with low vegetation cover (<5%)

dominated by low-growing, xerophytic shrubs (Osborne 1992; Oatham 1996;

Roshier etal. 1996). Two sites were coastal, two inland and a fifth intermediate from

the coast. The closest locations were about 100 km apart and the furthest 350 km.

All sites were accessible by 4WD vehicle but were remote from major centres of

human population. A GPS was used to map and locate each sampling point.

Pitfall Trapping

Invertebrates were sampled at the five trapping locations in Abu Dhabi (see Figure

1.1). Table 4.1 shows the site characteristics and summary statistics for the

arthropod communities, with total plant species counts from Osborne (1992) and

cover values from quadrat data in Roshier etal. (1996). Pitfall trapping was used to

assess ground-dwelling invertebrate occurrence and abundance. For many desert

invertebrates, closely spaced pitfall traps yield pseudo-replicates of numbers that

are not spatially independent with respect to the movements of individual animals.

Therefore, to obtain a replicated design for statistical analysis, a line of traps was

used as the unit of replication, pooling the data from individual pitfalls along the line.

At each of the five study sites, three lines of 20 traps were placed on mobile sand

and a further three on compacted inter-dune plains (termed gravel here for brevity),

spacing lines at least 500m apart. Individual pitfalls were 750ml polypropylene

beakers (pint "Rollers"), 83mm diameter and 138mm deep, placed in the ground

with their rims flush with the soil surface.

91

Plate 4.2 Baynunah Plate 4.3 Medinet Zayed

Plate 4.4 Public Hunting Triangle

ui >■ -

Plate 4.5 Khatam Plate 4.6 Um Az Zimul

Baynunah Medinet Zayed Public Hunting Triangle

Khatam Um Az Zimul

Approx. location (latitude, longitude) 24°00‘, 52°36' 23°46', 54°06' 24°45', 55°00* 23°18‘, 55°18' 22°54‘, 55°12'Distance to coast (km) 17 32 27 102 162

Elevation of site (m) 30 80 70 160 100

Total no. plant species (spring 1992) 42 18 46 26 17

Mean ± SD (n) % perennial cover 4.1±2.10(8) 3.2±2.15(4) 4.2±2.78 (4) 3.4±2.10(11) 1.7±2.92(11)

Annual average min. soil temp. °C 23.0 23.9 24.1 25.9 26.3

Annual average max. night % humidity 79.9 75.8 84.6 64.5 53.9Arthropod diversity (Shannon-Wiener H\ base 2) 1.57 2.29 2.79 2.01 1.86

No. of equally common arthropod taxa ( 2 " ) 3.00 4.90 6.90 4.04 3.63

No. arthropods caught 15090 9881 5449 11038 11938

No. arthropod taxa caught 32 32 33 28 25

Table 4.1. Site characteristics and summary statistics for the arthropod communities. The total plant species counts are taken from Osborne (1992) and the cover values from quadrat data analysed by Roshier et al. (1996).

CDro

93

Traps were set for one night (approximately two hours before dusk to two hours

after dawn) within a period three days either side of the new moon once every 28

days. Few arthropods are active during daylight hours and the trapping regime

sampled the main periods of arthropod activity.

Trapping was carried out 24 times from 12 October 1993 to 29 August 1995 (i.e. for

about two years) using the same study sites but not the same positions for lines

which were randomly chosen within a block of about lOkm^. The data therefore

consist of three replicated random samples per substrate per site, repeated on 24

occasions, that are independent in both space and time (based on a total of 14,400

individual pitfall traps).

Climatic data

Soil temperature, air temperature and relative humidity were recorded at one

randomly chosen sand pitfall line at each site each month. The severe operating

conditions sometimes caused the data-logger to malfunction and the data set is

unfortunately incomplete. Where data were available, two robust measures from the

logged data (minimum soil temperature and maximum humidity) were used for the

analysis. The mean monthly minimum air temperatures and total rainfall from a

reputable climatic station were also incorporated into the analyses. These data were

averages from the years 1982 to 1992 for Abu Dhabi International Airport

(Bottomley 1996).

Data analvsis

All captured animals were identified to the finest taxonomic level possible, but it was

not always possible to determine to species level. Table 4.2 lists the taxa caught

during the study, excluding those where fewer than 20 individuals were caught over

two years. For reliability and ease of analysis, only the more robust taxonomic

determinations are explored. Differences between sites, substrates and trapping

periods were assessed using ANOVA on log transformed data (to improve

normality). The percentage similarity of the sand and gravel communities at the five

sites was calculated, based on 35 taxa and clustered using an Unweighted Pair-

Group Method using simple Averages (UPGMA) without standardising or

transforming the data (Krebs 1989).

94

Class Order Superfamily/Family

Genus/Species

Arachnida 2.63%

Insecta 97.34%

Crustacea 0.02% Scolopendrida 0.01%

Araneae 1.51% Scorpiones 1.06%

Solifugae 0.06%

Coleoptera 8.35%

Hymenoptera 76.37%

Isoptera 0.07% Diptera 0.16% Orthoptera 0.16% Mantodea 0.06%

Neuroptera 0.01% Hemiptera 0.12% Lepidoptera 0.10% Thysanura 11.95% Isopoda 0.02% Scoiopendromorpha 0.01%

Buthidae 1.06%

Carabidae 0.21%

Curcuiionidae 0.06% Histeridae 0.14% Scarabaeoidea 0.34%

Tenebrionidae 7.54%

Others 0.06% Formicidae 75.36%

Mutiiiidae/Bradybaenidae 0.98% Others 0.03%

Sphaeroceridae 0.16% Tettigoniidae 0.16% Eremiaphiiidae 0.05% Others 0.01% Myrmeieontidae 0.01 %

Lepidoptera 0.10% Lepismatidae 11.95% Porceiiionidae 0.02%

Buthacus yotvatensis nigroaculeatus 0.60% Vachoniolusminipectenibus/globimanus0.26%Compsobuthus arabicus 0.10%Apistobuthus pterygocercus 0.04%nr Galeodes arabs 0.06%

Scarites guineensis 0.08% Anthia duodecimguttata 0.12%

nr Saprinus chalcites 0.14% Scarabaeus cristatus 0.11% Aphodius spp. 0.20% Apentanodes/Arthrodibius 0.70%Akis elevata 0.08%Blaps kollari 0.52%Erodius spp. 0.30%Mesostena puncticollis 3.50% Tentyrina palmeri 0.38% Ocnera/Trachyderma philistlna 0.08%Prionotheca coronata 1.22% Pimelia arabica 0.18% Phaeotribon/Pachycera sp. 0.38%Prochoma sp. 0.05% Sceiosodis besnardi 0.08%

Catagiyphis spp. 0.50% Cardiocondyla gallagheri 0.13%Camponotus spp. 0.36% Crematogaster spp. 8.81% Messor spp. 2.66% Monomorium spp. 62.66% Lepisiota nigrescens 0.17%

Psammotermes spp. 0.07%

Piatycleis sp. 0.16% Eremiaphiia gene 0.05%

Scoiopendra mirabilis 0.01%

Table 4.2. Composition of the 53,396 arthropods caught by pitfall-trapping over two years in Abu Dhabi, nr = near. Genera and species are only listed where more than 20 individuals were captured.

95

Species diversity was calculated using the Shannon-Wiener index, /-/'and its

transposition 2"' (Peet 1974), which is the number of equally common taxa that

would produce the same diversity as /-/’ (Krebs 1989).

4.1.3 Results

The arthropod communitv

Around 53,400 invertebrates were captured over 24 months, of which 97.3% were

insects and 2.6% arachnids (Table 4.2). The dominant insect orders were

Hymenoptera (76.4% of which 75.4% were ants), Thysanura (12%) and Coleoptera

(8.4%). The Araneae comprised 57.4% of the arachnids, the remainder being

scorpions (40.3%) and solifugids (2.3%).

Temporal variation in total catch

Arthropod numbers generally differed significantly over time, among the five sites

and between the two substrates, often with significant interaction (Table 4.3). The

catch of total arthropods closely matched the annual temperature cycle measured

both by the soil probe and the annual average (Figure 4.1). The average catch

doubled with every 6-7°C rise in minimum soil temperature. The total catch also

reached a peak after the average timing of the annual winter rains (Figure 4.1).

The interaction between site and time is well-illustrated by the differences between

the abundance patterns in relation to temperature (Figure 4.1). Simplifying these to

the correlation between log catch and minimum soil temperature showed a

difference in the strength of the relationship between Baynunah, Medinet Zayed and

the Public Hunting Triangle as against Um Az Zimul and Khatam (Table 4.4). Taking

these groups of three and two sites respectively, there was no curvilinear

component in a regression of log catch on temperature for the first group

(temperature: t=2.62, p=0.009; temperature^: t=-0.56, p=0.58; n=396, adj.

r^=35.5%), but a significant quadratic component for the second (temperature:

t=3.23, p=0.001; temperature^: t=-2.57, p=0.011; n=246, adj. r^=12.4%). Plots of the

data (Figure 4.1) showed that arthropod numbers in the second group (inland sites)

rose with increasing temperature until about 28°C but then reached a plateau. For

the other sites, however, numbers rose with temperature to the maximum 37°C

recorded.

Source of variation DF Arthropods Arachnids Insects Buthids Tenebrionids Ants

Site 4 17.00 18.80 17.12 22.89 18.90 11.08

Sampling period 23 26.53 9.79 25.77 8.96 26.44 15.20

Substrate 1 104.86 15.09 109.84 0.14 n.s. 24.46 64.77

Site*sampling period* substrate 92 1.59 1.13 n.s. 1.55** 1.21 n.s. 1.80 1.92

Site*sampling period 92 4.66 2.56 4.47 1.80 4.11 4.25

Site*substrate 4 5.26 3.71** 5.07 7.30 12.38 7.28

Sampling period*substrate 23 4.46 2.35 4.22 1.76* 3.09 4.35

Error sum of squares 480 57.476 27.07 61.97 17.31 38.54 116.17

Table 4.3. ANOVA F statistics for differences in the log catch of various arthropod taxa at different sites, on different substrates and for

different sampling periods. All values are significant at p<0.001 unless otherwise marked.

(OOÎ

97

Sample number Sample number

40

j 3 0

I 20 P

10

All

I0 0

40 3

p 30

« 20

0

40 3

p 30I

« 20

« 10

Dec June1994

Dec June1995

2040

---/

40 3

20

40 3

30

Dec Dec June1995

June1994

Figure 4.1. Relationships between the average catches at the sites and climatic

conditions. For all figures the dashed line is the minimum soil temperature and the

solid line the averaged catch, drawn by distance-weighted least squares (DWLS)

smoothing through the original data points. The top left figure for all sites also shows

the DWLS smoothed minimum air temperature (dotted line) and bar charts for average

annual rainfall at Abu Dhabi International Airport. Note that these data were

interpolated to convert monthly values to 4-weekly averages, explaining the slight

differences between years. Sampling periods were exactly four weeks apart. The sites

were: B - Baynunah, M - Medinet Zayed, P - Public Hunting Triangle, K - Khatam and

U - Um Az Zimul.

98

Baynunah MedinetZayed

PublicHuntingTriangle

Um Az Zimul

Khatam

Arthropoda 0. 66 0. 61 0. 63 0. 37 0. 28*

Arachnida 0. 26 n.s. 0. 48 0. 35 0. 11 n.s. 0. 36Insecta 0. 65 0. 60 0. 63 0. 38 0. 27 n.s.Buthidae 0. 45 0. 54 0. 17 n.s. 0. 16 n.s. 0. 43Tenebrionidae 0. 34 0. 71 0. 33** 0. 27** 0. 25 n.sFormicidae 0. 62 0. 41 0. 54 0. 22 n.s. 0. 13 n.s.

Sample size 132 132 132 126 120

Table 4.4. Pearson correlations between the minimum soil temperature and log catch

of various arthropod groups at five desert sites. All correlations are Bonferroni

corrected and significant at p < 0.001 unless indicated by n.s. (not

significant),*(p<0.05) or ** (p<0.01).

Spatial variation in total catch

Differences among sites were dependent on taxa (Figure 4.2). Taking all arthropods

(or the Insecta), Khatam had the highest average log catch and Public Hunting

Triangle, the lowest. In contrast, the arachnids were most abundant at Medinet Zayed

and least numerous at Um Az Zimul. This difference was due to spiders; when

scorpions (Buthidae) were considered alone, the pattern differed from that of the

insects only in the reversal of Baynunah and Um Az Zimul. The Formicidae showed

similar differences to the Buthidae with Khatam once again being the dominant site.

Tenebrionids, however, were most abundant at Baynunah.

As Table 4.1 shows, the total catch of arthropods was, in fact, highest at Baynunah in

contrast to the test using Fisher's Least Significant Difference (LSD) in Figure 4.2.

While a few catches were very high at Baynunah, they were consistently high at

Khatam and therefore, on average, higher when log transformed. The coefficients of

variation of the log transformed catches were 1.33%, 1.85%, 2.10%, 3.60% and 3.91%

at Khatam, Um Az Zimul, Public Hunting Triangle, Baynunah and Medinet Zayed

respectively, showing greater variation between catches at Baynunah than at Khatam.

Taxon Sites

Arthropods or Insecta K M U B PI------------- 1h

I--------- 1

Arachnida M B K P U

Formicidae K M B U

Buthidae K M B U P

I 1

Tenebrionidae B M K U PI----------------------------- 1

H

99

Figure 4.2 Differences in log catch at the five sites (Fisher's LSD test). Lines link sites

that were significantly different (p<0.05). Sites are ordered by abundance from left

(highest) to right (lowest). The sites were: B - Baynunah, M - Medinet Zayed, P - Public

Hunting Triangle, K - Khatam and U - Um Az Zimul.

100

Spatial variation in taxonomie diversity

Biodiversity statistics and environmental characteristics for the five sites are

summarised in Table 4.1. Of the possible 35 taxa in the analysis, the best site (Public

Hunting Triangle) had 33 whereas Um Az Zimul had only 25 taxa. Although Baynunah

and Medinet Zayed both had 32 taxa, the diversity as measured by the Shannon-

Wiener index was lower at Baynunah than even at Um Az Zimul. Baynunah showed a

highly skewed distribution of abundance and hence the evenness component of

diversity down-weighted the overall index value.

The number of arthropod taxa at a site was linearly related to relative humidity (r=0.99,

p=0.002) and distance to coast (r=-0.99, p=0.002), a surrogate for humidity amongst

other factors (Table 4.1). The non-significant relationship with number of plant species

appeared good except at Medinet Zayed where the number of arthropod taxa was

higher than expected for the number of plant species.

While all the taxa in Table 4.3 (except Buthidae) differed significantly in abundance

between substrates with higher catches on sand, the gravel communities were more

diverse at four out of five sites (Table 4.5). The exception was Khatam where the

gravel community was particularly poor with a diversity equivalent to only 3.04 equally

common taxa. The richest habitat was the gravel at the Public Hunting Triangle with

9.24 equally common taxa (30 taxa overall). The Public Hunting Triangle also had the

richest sand community with 5.45 equally common taxa.

Using cluster analysis, the least similar communities were separated by site rather than

substrate, suggesting that the greatest differences occurred at the geographic rather

than the local scale (Figure 4.3). Note the separate cluster for the rather impoverished

communities at the Public Hunting Triangle. The strong similarity between the sand

and gravel communities at Baynunah (89.8%) is apparent in Table 4.6, simplified to 14

taxa for ease of interpretation. However, at Medinet Zayed, Um Az Zimul and Khatam,

clustering of substrates and sites was mixed. In particular, the communities at Khatam

resulted in mixed clusters. Khatam's sand community was more similar to that at Um

Az Zimul than the sand and gravel communities were at Um Az Zimul itself. Similarly,

the Khatam gravel community split the adjacent clustering of Medinet Zayed's

communities. Percentage similarities ranged from 43.9% to 89.8%.

101

Site Substrate Shannon-Wiener diversity H’ (base 2)

No. of equally common taxa

No. taxa

Baynunah Gravel 1.75 3.37 31Khatam 1.60 3.04 25Medinet Zayed 2.33 5.04 29Public Hunting Triangle 3.21 9.24 30

Um Az Zimul 1.99 3.98 21

All sites 2.23 4.69 35

Baynunah Sand 1.46 2.76 30Khatam 2.22 4.65 26Medinet Zayed 2.12 4.34 31Public Hunting Triangle 2.45 5.45 29Um Az Zimul 1.77 3.40 24All sites 2.05 4.14 34

Table 4.5 Arthropod community statistics for the five desert sites split by substrate, (based on 35 taxa). The number of equally common taxa = 2 " .

Site P P U K U M K M B BSubstrate Sand Gravel Gravel Sand Sand Sand Gravel Gravel Sand Gravel

Figure 4.3 Cluster analysis of the sand and gravel communities at five desert sites.

The distance-metric used was proportional similarity and clustering was by UPGMA.

The sites were: B - Baynunah, M - Medinet Zayed, P - Public Hunting Triangle, K -

Khatam and U - Um Az Zimul.

102

Percentage composition of the sand and gravel communities is illustrated in Table 4.6.

Both Baynunah and the Public Hunting Triangle had 13 taxa on sand and 14 on gravel,

and Medinet Zayed had 13 on both sand and gravel. The two inland sites, however,

had fewer taxa, Um Az Zimul having only ten taxa on sand and eight on gravel. The

missing taxa were the Carabidae, Tettigoniidae and Isoptera; the latter two were also

absent from Khatam. In contrast, the Thysanura were both proportionally and

numerically more abundant at these inland sites than elsewhere. Termites and ground

mantids, Eremiaphila gene Febv., were always more common on gravel than sand.

4.1.4 Discussion

Communitv composition

The total catch of around 53,400 arthropods was dominated by ants (Formicidae),

thysanurans, tenebrionids and arachnids. Very few studies have examined entire

desert arthropod assemblages, making comparisons among deserts difficult. Pitfall

traps in Saudi Arabia (Combreau & Rambaud 1995) caught slightly more insects

(98.10%) and fewer arachnids (1.76%) than in this study, and 0.15% crustaceans

compared with only 0.02% from Abu Dhabi. In both areas, by far the most numerous

animals captured were Hymenoptera, particularly ants, with one genus {Monomorium)

making up 62.7% of all invertebrates in UAE. Social insects such as ants and termites

are abundant in all terrestrial ecosystems but, in deserts, may contribute up to an order

of magnitude greater biomass than herbivorous mammals (MacKay 1991). The

diversity of tenebrionids, scorpions and solifugids is greater in deserts than most other

terrestrial ecosystems (Polis 1991b; Polis & Yamashita 1991) and tenebrionids were

well-represented in Abu Dhabi, although solifugids comprised only 0.06% of the catch,

possibly because large adults could escape from the dry pitfall traps.

Gravel Sand

Baynunah Khatam MedinetZayed

PublicHunting

Triangle

Um Az

Zimul

Baynunah Khatam Medinet

Zayed

Public

HuntingTriangle

Um Az

Zimul

Formicidae 82.67 78.51 73.45 55.12 54.22 87.21 69.42 76.77 72.12 72.34Tenebrionidae 7.75 5.47 14.58 10.11 11.65 6.45 7.82 8.08 6.23 4.87Lepismatidae 2.49 11.84 4.88 21.70 32.02 1.79 18.50 8.76 14.44 20.28Araneae 2.12 1.15 1.60 4.19 0.78 0.84 1.24 2.81 2.06 1.10Buthidae 1.67 1.44 2.92 0.74 0.67 0.67 1.22 0.97 0.98 0.36Scarabaeoidea 1.00 0.18 0.10 2.96 0.00 0.27 0.06 0.60 0.32 0.03Wasps 0.52 1.26 1.15 2.65 0.32 0.49 1.30 1.11 1.69 0.88Isoptera 0.45 0.00 0.05 0.62 0.00 0.04 0.00 0.02 0.00 0.00Tettigoniidae 0.45 0.00 0.74 0.68 0.00 0.12 0.00 0.18 0.03 0.00Histeridae 0.25 0.00 0.00 0.18 0.00 0.18 0.09 0.02 0.71 0.08Diptera 0.22 0.02 0.05 0.06 0.00 1.55 0.14 0.25 1.03 0.02Carabidae 0.20 0.09 0.31 0.37 0.00 0.35 0.17 0.34 0.34 0.00Eremiaphilidae 0.12 0.02 0.12 0.25 0.18 0.01 0.00 0.00 0.03 0.03Galeodes 0.10 0.02 0.05 0.37 0.18 0.04 0.05 0.11 0.03 0.00

Table 4.6. Percentage composition (number of taxon x 100/total captured) of the sand and gravel communities at the five sites, reduced to 14

taxa for simplicity. See Table 4.2 for a breakdown of the taxa.ow

104

Temporal variation

Arthropod catches varied temporally and trends closely matched the yearly cycle in

minimum air or soil temperature. (The slight decrease in catches around peak

temperatures (Figure 4.1) resulted from combining abundance curves from different

taxa.) As the various measures of temperature (minimum, maximum, mean etc.) show

the same seasonal pattern in Abu Dhabi (Bottomley 1996) it is not wise to be more

specific than to regard catches as correlated with temperature. Ahearn (1971),

however, suggested that minimum temperature was one of two factors (with rainfall)

determining the tenebrionid beetle catch in an Arizona desert. Rainfall in Abu Dhabi

coincides with low winter temperatures and it is not possible in this study to separate

their effects.

Several abiotic and biotic factors could account for this overall pattern, always recalling

that pitfall traps measure abundance and activity rather than population size (e.g. Crist

& Wiens 1995). The simplest explanation is that increasing temperature causes a rise

in arthropod abundance through breeding, increased activity or both (Ahearn 1971). An

explanation involving both abiotic and behavioural factors is that some arthropods alter

their daily cycle of activity depending on temperature (Holm & Edney 1973; Ayal &

Merk11994). In the summer, these arthropods become nocturnal as opposed to diurnal

and so might be caught at night only in this season. In the sandy desert of Abu Dhabi,

there are few day-active arthropods at any time of year, in contrast to the rocky

mountain areas of the country (personal observation). However, the predominantly

diurnal genus Erodius (Tenebrionidae) contributed 0.3% to the overall catch (and was

only caught in the months from December to May) confirming that the sampling regime

could detect diurnal species. A purely biotic explanation is that predation is higher

during the winter when non-resident migrants such the houbara are present. For

example, Ayal & MerkI (1994) believe that white storks {Ciconia ciconia) may

significantly affect tenebrionid abundance in Israel.

Spatial-temporal interaction

The differences in temporal changes among sites may be explained by climate.

Although good climatic data are few, inland sites in Abu Dhabi tend to have higher

summer and lower winter temperatures than coastal sites (Bottomley 1996).

Furthermore, while the maximum relative humidity near the coast rarely drops below

105

85% over the year, inland sites drop to 70% and below from April to September.

Minimum humidity inland is extremely low (10%). Radiation fog is also common,

especially just inland from the coast, although it is less frequent in summer than winter

(Bottomley 1996). At dawn, condensation forms on desert plants with water literally

soaking the sand beneath large shrubs such as Haloxylon persicum. It appears that

desert arthropods can tolerate the high temperatures and remain active near the Abu

Dhabi coast in summer because water is available from the humid air (see also Seely

1979). Even if severely desiccated, tenebrionid beetles exhibit a remarkable ability to

recover if water becomes available (e.g. Naidu & Hattingh 1988). The inland desert

sites were both hotter and drier in summer, resulting in arthropods either avoiding

thermal stress by taking refuge in burrows (Louw & Seely 1982) or dying from

dehydration when prolonged dry periods prevent rehydration.

If this argument is correct, then a general decline in summer catches with distance into

the Empty Quarter it to be expected, along with a general decrease in arthropod

biodiversity as arid intolerant species are eliminated. Winter catches are probably also

lower in the interior as desert temperatures may reach freezing point in December and

January in the Central Region of Saudi Arabia (Faragalla & Adam 1985). The Abu

Dhabi data (Table 4.6) clearly showed fewer Isoptera and tettigoniids at the inland

sites. Overall, inland sites held fewer taxa and fewer individuals than coastal sites. The

exception was at the Public Hunting Triangle. This site held 33 taxa but only 42% of

the individuals found at other near-coast sites (true for both substrates), and did not

appear impoverished in its plant species number, composition or density (Table 4.1).

However, the level of grazing by goats and camels in the Public Hunting Triangle is

higher than at any other site and the lower arthropod numbers may be due to

excessive grazing and disturbance by livestock and animal herders. Ayal & MerkI

(1994) studied non-grazed enclosures and concluded that grazing affected the relative

abundance of tenebrionids species rather than species composition.

Spatial variation

In general, there were greater differences in the arthropod communities between

geographic locations than among habitats. Several studies of community differences

according to substrate show soil type to be important for habitat segregation (Thomas

1983; Sheldon & Rogers 1984; Crawford 1988; Ayal & Merk11994). In Abu Dhabi,

gravel sites always held fewer individuals (from 31% of the sand community at Um Az

106

Zimul to 74% at Medinet Zayed) but the number of taxa and diversity did not differ

consistently by substrate. Crawford (1988) suggests that sands are more suitable

habitats than compacted substrates for desert arthropods, especially when conditions

are extreme. Sand is a poor heat conductor, its porosity allows water to accumulate at

depths below the evaporation zone, and it is easily burrowed. Compacted substrates

resist burrowing activities except by specially adapted animals. However, we know little

of the dispersal abilities of desert arthropods which could be considerable for larger

animals such as the arachnids, and they may simply be caught in pitfalls on gravel

while foraging away from their burrows or retreats elsewhere.

The absence of carabids from the site furthest inland is consistent with their preference

for more mesic habitats and they are generally replaced by the physiologically adapted

nocturnal tenebrionids in extreme hot deserts (Ahearn 1971). Carabids have high

respiratory water loss which must be replaced by feeding on animal prey with a

relatively high water content, while tenebrionids have low rates of water loss and are

predominantly detritivores (Zachariassen etal. 1987). Thysanurans, which were also

more common at inland sites, have very low rates of water loss per unit area and can

survive extremely arid conditions (Edney 1971).

Conclusion

Much of the literature relating to desert invertebrates is based on studies carried out in

regions with less extreme climates and with a higher percentage cover of vegetation.

In Abu Dhabi, the climate is arid or hyper-arid (Bottomley 1996) and perennial

vegetation cover is less than 5% on average (Roshier etal. 1996), only boosted for

short periods by ephemerals following heavy rains. Productivity levels would therefore

be expected to be low in Arabia with fewer arthropods and lower diversity than deserts

with more benign climates. Within Abu Dhabi's deserts (and perhaps Arabian deserts

in general), spatial variation is probably driven by water availability and the extra

humidity near the coast benefits the vegetation and supports a higher taxonomic

diversity of arthropods than further inland.

107

4.2 Does the phase of the moon influence invertebrate trap catch?

4.2.1 Introduction

Moonlight is most apparent in open habitats such as deserts, and the phase of the

moon influences the behaviour of many vertebrates and invertebrates (Beasley &

Adams 1994). In general, predators are thought to be more active at full moon

because they take advantage of the greater light levels when seeking prey (Clarke et

al. 1996; Kirby 1997). Conversely, prey species may be less active, with reduced

foraging effort, because of an increase risk of predation especially from vertebrates

(Clarke etal. 1996; Vasquez 1994; Skutelsky 1996). The effect of moonlight on pitfall

trap catch has not previously been investigated.

The hypothesis that the abundance and diversity of ground-dwelling invertebrates

captured in pitfall traps would differ between new and full moons was tested.

Differences would result from changes in the risk of predation, the ease of

encountering prey and the visual awareness of invertebrates to pitfall traps (although

these hypotheses could not be separated in this study). These factors would tend to

increase predator and decrease prey abundance at the full moon.

4.2.2 Methods

Invertebrate trapping

Ground-dwelling invertebrates were sampled using overnight pitfall traps at the Public

Hunting Triangle, with three replicate lines of 20 trap, pitfall-transects on two

substrates (see Section 4.1.1). Six samples were obtained at the full and new moons,

once every 14 days from 1®* October 1993 until 1S‘ March 1994 (a total of 1440 pitfall

traps). Cloud cover was minimal and it was assumed that full and new moons

represented maximum and minimum moonlight levels, although light levels were not

measured. Temperature and relative humidity were recorded using a datalogger (see

Section 4.1.1).

Data Analvsis

Data were log-transformed to ensure normality and all analyses were carried out using

Systat (Wilkinson 1993). Trends in total capture and taxonomic diversity were

examined, and data were divided into four groups applicable to desert invertebrate

108

communities (Polis 1991c), which were likely to respond differently to moonlight:

predaceous arthropods, macroarthropod detritivores, herbivorous insects and social

insects. Predaceous arthropods exhibit trophic and taxonomic diversity, but are strict

predators, parasites or parasitoids (Polis & Yamashita 1991), Macroarthropod

detritivores are omnivorous, ground-dwelling invertebrates consuming mainly dead and

some living matter, but are not obligate predators (Crawford 1991). Coprophages and

suspected detritivores, such as anthicid beetles which are associated with stones and

debris in sandy areas in North America (Dillon & Dillon 1972), were also included in

this group. Herbivorous insects rely on their host plants for food, which in turn are

dependent upon abiotic factors, such as rainfall that are often limiting in deserts

(Wisdom 1991). Most desert social insects are ground-dwelling ants and termites,

which are characteristically colonial and high in number and biomass (MacKay 1991).

However, they are trophically diverse and include granivores, detritivores, herbivores,

general scavengers and predators.

Recent advances in taxonomy gave greater confidence to the determinations

especially for ants (see Collingwood & Agosti 1996), and it was possible to examine

diversity at a higher taxonomic level than in Section 4.1. However, spiders and

thysanurans remain poorly known and were only recorded by order.

The number of invertebrates captured in pitfall traps is dependent upon date and has

an annual cycle, following a declining curve with ambient temperature during the winter

(see Figure 4.1; Tigar & Osborne 1997). Clearly, invertebrates could not be sampled

from full and new moons on the same date, although the analyses needed to control

for the effect of date. Exploratory regression analysis suggested that sample period

(i.e. date) and its square could adequately describe the general decline in numbers

during the winter. Therefore GLMs (General Linear Models) were used to test whether

the total number of invertebrates or number of taxa caught in pitfall traps were affected

by phase of the moon (new or full), substrate (sand or gravel) and their interaction,

while using sample period (two week increment) and its square as covariates to control

for the effect of sampling at different times. Community composition, according to the

phase of the moon and substrate, was examined using Principal Components Analysis

(RCA) (Gauch 1982).

109

4.2.3 Results

The arthropod communitv

A total of 58 taxa were recorded, and there appeared to be differences in the species

composition between both phases of the moons and substrates, summarised by name

and number of taxa in Tables 4.7 & 4.8 respectively.

A wide variety of predaceous arthropods were caught, with 17 taxa representing nine

orders and at least 11 families, including scorpions, mantids, spiders, solifugids, ticks,

carabids, histerids, mutillids, tiphiids and scolopendrids. There were 16

macroarthropod detritivore taxa, with many thysanurans and tenebrionids, of which 12

species were recorded. Ants (Formicidae) were the only family of social insects

captured showing high diversity (21 species from 5 genera). Herbivorous insects

usually occur on their host plant and pitfall trapping caught only five examples from

three orders: Lepidoptera, Coleoptera and Hemiptera.

TotalCapture

Number of Taxa by GroupPredaceous Macro- Herbivorous Arthropods arthropod Insects

detritivores

SocialInsects

Total taxa 58 17 16 4 21

At both full and new moon 28 7 9 1 11Only at full moon 8 1 2 2 3Only at new moon 22 9 5 1 7

On both sand and gravel 26 9 7 1 9Only on gravel 18 2 6 1 9Only on sand 14 6 3 2 3

Table 4.7 Summary of the number of arthropod taxa captured in pitfall traps, grouped

by phase of the moon (full, new or both) and by substrate (sand, gravel or both).

Group Order Family Species Name MoonPredaceous Arthropods Scorpiones Buthidae Androctonus crassicauda FN

Apistobuthus pterygocercus NButhacus yotvatensis FNCompsobuthus arabicus NVachoniolus globimanus N

Mantodea Eremiaphildae Eremiaphila gene FNAraneae Indeterminate indeterminate FNSoiifugae Galeodidae Gaieodes arabs N

Galeodes sp. NAcarina Ixodidae Hyaiomma sp. NColeoptera Carabidae Anthia duodecimguttata FN

Scarities guineensis NHisteridae nr Saprinus chalcites FN

Hymenoptera Mutiiiidae Indeterminate FTiphiidae indeterminate N

Neuroptera Myrmeieontidae Larva (ant lion) FNScolopendromorpha Scolopendridae Scolopendrida mirabilis N

Macroarthropod Detritivores Coleoptera Tenebrionidae Adesmia sp. FNAkis eievata NArthrodibius cicatrix NSlaps koiiari FNMesostena puncticoilis FNPhaeotribon/Pachycera FPimelia arabica FNPrionotheca coronata FNProchoma nr. ciypeaiis NSceiosodis besnardi FTentyrina paimeri FNZophosis migneauxi N

Group Order Family Species Name MoonMacroarthropod Detritivores Coleoptera Anthicidae Mecynotarsus nr semicinctus FNcontinued Scarabaeidae Scarabaeus christatus N

Melolonthinae (Indeterminate) FNThysanura Lepismatidae Thermobia sp. FN

Herbivorous Insects Coleoptera Curcuiionidae Eiasmobaris ?aiboguttata FOcladius sp. F

Hemiptera Miridae indeterminate NLepidoptera indeterminate Adult micro-moth FN

Social Insects Hymenoptera Formicidae Camponotus fellah NCamponotus oasium NCamponotus thoracicus FNCamponotus xerxes FNCataglyphis albicans FNCatagiyphis txombycinus FCataglyphis cinnamomeus NCatagiyphis fiavobrunneus NCataglyphis lividus FNCatagiyphis minimus NCatagiyphis sabuiosus FNCrematogaster antaris FNCrematogaster sp B FMessor ebeninus FNMessor foreli FNMessor meridionaiis NMessor sp A FNMonomorium fezzanense FMonomorium New sp. NMonomorium tumaire FNMonomorium wahibiense FN

Table 4.8 Total list of taxa caught in pitfall traps around full (F) and new (N) moons, shown according to four biological groups.

111

Variation in arthropod abundance

The GLM predicting log number of invertebrates caught while controlling for the effect

of time, showed highly significant differences between the number of predaceous

arthropods caught at new and full moons (Table 4.9). However, moon phase had no

significant effect on the number of total invertebrates, macroarthropod detritivores,

herbivorous or social insects caught in pitfall traps. In addition, there were significant

differences between catches of total arthropods and macroarthropod detritivores

according to substrate. There was a significant interaction between phase of the moon

and substrate only for the social insects.

Source of variation

TotalLog number of arthropods caught in pitfall traps

Predaceous Macroarthropod Herbivorous Social Arthropods Detritivores Insects Insects

FACTORS

Moon Phase 1.30 n.s 13.04 1.67 n.s 0.40 n.s 0.66 n.s.

Substrate 10.24 ** 6.21 * 46.07 *** 0.05 n.s <0.01 n.s.

Moon Phase * Substrate

3.59 n.s. 0,03 n.s. 0.43 n.s. 0.05 n.s 6.92 *

C o v a r ia t e s

Sample Period Sample Period ^

19.24

10.36 ***

30.34 ***

25.41 ***

17.73 ***

11.17***

2.26 n.s

1.87 n.s

5 .1 6 *

1.34 n.s.

DF 1,354 1,66 1,66 1 ,66 1 ,6 6

Table 4.9 F statistics for differences in log total invertebrates, predaceous arthropods,

macroarthropod detritivores, herbivorous insects and social insects captured in pitfall

traps at different phases of the moon, substrates and their interaction, with sample

period and its square as covariates. Significance levels are indicated by *** (p <0.001),

** (p <0.01), * (p <0.05) or n.s (no significant difference.)

Variation in taxonomic diversitv

The results of the GLMs predicting the number of taxa caught in pitfall traps were

similar to those for the number of arthropods caught (Table 4.10). There were highly

significant differences between catches of predaceous arthropod taxa at full and new

moons, but not for other groups or total taxa. Trapping substrate had a significant

effect on the total number of taxa, and on the number of macroarthropod detritivore

112

taxa caught. There were also significant differences for the interaction between phase

of the moon and substrate for social insects. There were no other significant effects.

Log number of taxa caught in pitfall trapsSource of variation

Total PredaceousArthropods

MacroarthropodDetritivores

HerbivorousInsects

SocialInsects

FACTORS

Moon Phase 3.64 n.s 12.32 *** 1.37 n.s 0.40 n.s 0.40 n.s.

Substrate 6 .45* 3.70 n.s. 11.70 *** 0.05 n.s <0.01 n.s.

Moon Phase * Substrate

3.16 n.s. <0.01 n.s. 1.66 n.s. 0.05 n.s 6.95 **

C o v a r ia t e s

Sample Period 18.05 *** 17.67 *** 13.40 *** 2.26 n.s 2.21 n.s.

Sample Period ^ 12.88 *** 13.79 *** 9.51 ** 1.87 n.s 0.99 n.s.

DF 1,354 1,66 1, 66 1, 66 1 ,66

Table 4.10 F statistics for differences in log number of taxa for total invertebrates,

predaceous arthropods, macroarthropod detritivores, herbivorous insects and social

insects captured in pitfall traps between phases of the moon, substrates and their

interaction, with sample period and its square as covariates. Significance levels are

indicated by *** (p <0.001), ** (p <0.01), * (p <0.05) or n.s (no significant difference.)

Figure 4.4 illustrates graphically the result for the number of species of predaceous

arthropods and phase of the moon. The curve shows the trend in catch with time,

described by the covariates sample and sample squared. Note that all the full moon

means of the log number of taxa caught lie below the curve, while apart from samples

4 and 8, the new moon means are on or above the curve. Minimum values for the

relationship occurred at the 8th sample (13 January 1994), corresponding with the

minimum soil temperature recorded (10.6°C). Therefore, on average, more

predaceous arthropod taxa were caught around new moons than full moons. The

number of individuals caught showed a similar trend, indicating that both high numbers

and diversity of predaceous arthropods occur around the new moon.

113

<

2ü_

SCO

2.0

1.5

1.0

0.5

0.02 3 4 5 6 7 8 9 10 11 121

Sample no. (2 week intervals)

Figure 4.4 The relationship between log number of taxa of predaceous arthropods vs

sample number (solid line), with means and standard errors for catches at full

(triangles) and new moons (diamonds). Sample number indicates the two week

sampling interval from 1®' October 1993.

Species composition according to the phase of the moon and substrate

PCA identified two factors which together explained 50.2% of variation in species

composition among catches (Table 4.11; Figure 4.5). Factor 1 represents a trend

towards greater numbers of two macroarthropod detritivores: Lepismatidae and

Sceiosodis besnardi, and two social insects: Messor sp. A and Monomorium tumaire

(Table 4.11). Factor 2 represents a trend towards greater numbers of the social insects

Crematogaster antaris and Messor ebeninus. In addition, both factors were positively

influenced by increases in the social insect Monomorium wahibiense.

114

Species or family name Factor 1 Factor 2Adesmia sp. -0.046 -0.031Akis eievata 0.045 0.039Androctonus crassicauda 0.014 0.108Anthia duodecimguttata 0.467 0.047Apistobuthus pterygocercus -0.027 -0.009Arthrodibius cicatrix -0.031 0.015Blaps koiiari -0.093 0.042Buthacus yotvatensis 0.223 0.001Camponotus fellah -0.009 -0.029Camponotus oasium -0.031 0.015Camponotus thoracicus -0.060 -0.001Camponotus xerxes -0.031 -0.003Cataglyphis albicans 0.095 0.113Catagiyphis bombycinus 0.148 0.008Cataglyphis cinnamomeus -0.027 -0.024Cataglyphis fiavobrunneus -0.072 0.073Cataglyphis lividus -0.032 0.008Catagiyphis minimus 0.045 0.039Cataglyphis sabuiosus -0.073 -0.002Compsobuthus arabicus 0.062 0.024Crematogaster antaris 0.467 0.511Crematogaster sp. B 0.053 -0.003Eiasmobaris ?aiboguttata 0.093 0.005Eremiaphila gene 0.056 0.145Gaieodes arabs 0.013 -0.031Galeodes sp. 0.013 -0.031Hemiptera 0.090 0.079Hyaiomma sp. -0.066 0.036Lepidoptera 0.008 -0.014Mecynotarsus nr semicinctus 0.188 -0.029Melolonthinae 0.002 -0.075Mesostena puncticoilis 0.175 0.292Messor ebeninus -0.180 1.631Messor foreii -0.047 0.247Messor meridionaiis -0.108 0.054Messor sp. A 0.572 0.160Monomorium fezzanense 0.004 0.034Monomorium New sp. 0.021 -0.048Monomorium tumaire 1.116 0.163Monomorium wahibiense 1.483 0.504Mutiiiidae 0.391 0.005Myrmeleonidae Ant lion larva -0.053 -0.120nr Saprinus chalcites 0.149 -0.016Ocladius sp. 0.093 0.005Phaeotribon/Pachycera -0.040 -0.021Pimelia arabica 0.165 -0.008Prionotheca coronata 0.219 0.044Prochoma nr. ciypeaiis -0.034 -0.030Scarabaeus christatus 0.001 -0.024Scarites guineensis 0.006 -0.126Sceiosodis besnardi 0.662 0.277Scolopendrida mirabilis 0.001 -0.024Spiders (Araneae) 0.183 -0.152Tentyrina paimeri 0.515 -0.185Thermobia sp. 0.802 0.113Tiphiidae 0.188 -0.029Vachoniolus globimanus 0.052 -0.062Zophosis migneauxi -0.049 0.025

Eigenvalue

Percent of variance expiained

6.126

31.5

3.646

18.8

Table 4.11 Varimax rotated component loadings from the PCA, calculated from the

covariance matrix (n=24). Numbers in bold contributed 5% or more to the explained

variance for that factor.

2 -

CNJ

2 % 1 u_

0 -

-1

-2

-2

GF1

SF3□ SF2

GFi

SN5

F1

-1Factor 1

Figure 4.5 PCA ordination of the invertebrate communities grouped by substrate and phase of the moon. Shaded ellipses are new moon and

non-shaded are full moon groupings. Data points are labelled as follows: 8= sand (symbol = □), G= gravel (symbol = ♦), F= full moon, N=

new moon and 1 - 6 signify sample number.

116

Figure 4.5 suggests that the community composition varies according to substrate. In

general catches on gravel had higher values for factor 2, with lower values for factor 1,

apart from GN1. In contrast, most catches on sand had higher values for factor 1, with

lower values for factor 2. Differences in the two factors between phases of the moon

were less distinct. New moon catches on sand were tightly grouped, with low values for

both factors, while full moon catches were more widely spaced. Differences between

full and new moon catches on gravel were both widely spaced with no consistent

pattern.

There also appears to be a trend with sample number (1 to 6), a proxy value for date,

within the groupings by substrate. Earlier samples, 1 and 2, were more widely spaced

with higher values for both factors, while later samples, 5 and 6, were more closely

grouped and had lower values for both factors (Figure 4.5).

4.2.3 Discussion

Higher numbers of more diverse predaceous arthropods were caught at new moons

than full moons, confirming the hypothesis that pitfall trap catches differ according to

the phase of the moon. Predaceous arthropods are intermediate level predators that

must both capture prey and avoid predation (Polis & Yamashita 1991) and a probable

explanation for their reduced activity around full moons is to avoid vertebrate predators

which take advantage of higher light levels when searching for prey. The increased risk

of vertebrate predation to other intermediate predators, including scorpions and

rattlesnakes, has been implicated in reducing their foraging activity at full moons

compared with new moons (Skutelsky 1996; Clarke et a i 1996).

In addition, those predaceous arthropods with well-developed sight may be more

aware of pitfall traps at a full moon and be able to avoid capture. For example the

large-eyed carabid Scarites guineensis was only caught during new moons. However,

scorpions and solifugids generally detect their prey via vibrations rather than visual

cues (Polis 1990b; Cloudsley Thompson 1977). Adult Buthus occitanus Israelis

scorpions showed reduced activity on simulated moonlight nights compared with dark

nights, and those that were active ambushed their prey under bushes rather than in the

open; although juveniles did not alter their activity in relation to light levels (Skutelsky

1996). These behavioural differences were thought to be based on illumination levels,

which were used to evaluate the risk of predation and availability of food. However, an

117

introduced population of Euscorpius sp. in UK also shows reduced activity during full

moons (T. Benton, pers. comm.), even though artificial lighting maintains permanently

high light-levels. Perhaps scorpions perceive moonlight through other means, such as

variations in the gravitational pull of the sun and moon upon the earth. In UAE, nine of

the 16 predaceous arthropods taxa recorded, including three scorpions {Apistobuthus

pterygocercus, Vachoniolus globimanus and Compsobuthus arabicus) were never

captured at a full moon (Table 4.7). As well as vertebrate predation, small species or

juvenile predaceous arthropods will be subjected to intra-guild predation (Polis &

Yamashita 1991). While the size of the arthropods captured in UAE was not recorded,

adult C. arabicus never exceeded 3 cm in body length and are much smaller than other

scorpions. For example, Androctonus crassicauda can measure over 9 cm (Vachon

1979) and was present at both full and new moons.

Other studies from the Negev desert where B. o. Israelis occurs, suggest that

vertebrates such as white storks Ciconia ciconia and stone curlews Burhinus

oedicnemus reduce the activity and abundance of arthropods, especially tenebrionids

(Ayal & Merk11994). In Arabia, houbara often forage at night (Anegay 1994),

particularly on nights with bright moon light, and this is thought to give them a visual

advantage when hunting nocturnal animals (Combreau & Launay 1996).

Preliminary data also suggested that the phase of the moon affected the

activity/abundance of other invertebrates (Tables 4.7 & 4.8), but these effects were not

significant. Some taxa may have been placed in the wrong biological group for the

analysis, e. g. predatory ants could be placed with the predaceous arthropods.

However, the lack of knowledge of the biology of the Arabian fauna makes it difficult to

determine guilds and trophic levels, and is compounded by the complexity of desert

food webs where omnivory and trophic diversity interact, and animals do not always

remain within one trophic level (Polis 1991b). For example, some granivorous ants

deviate from the characteristic trophic level of their genus (MacKay 1991) and will also

feed upon arthropods in order to increase their dietary protein and water levels. In

terms of numbers captured in UAE, ants were dominated by granivores {Messorsp.)

and general foragers associated with aphids and their exudates {Crematogastersp.).

The PCA ordination suggested that changes in the abundance of six species of ants

and three macroarthropod detritivores made a significant contribution to the two factors

which explained about half the variation in the capture of arthropod taxa. PCA also

118

indicated that there was a strong effect of substrate on community composition,

agreeing with the findings of a larger data set (Tigar & Osborne 1997; Section 4.1).

The strong influence of substrate on the numbers and diversity of arthropods captured

in the pitfall trap may have reduced the effect of the phase of the moon, and there was

a significant interaction for these two terms in the social insects.

The experiment was designed around the lunar calendar and although cloud cover is

rare in Abu Dhabi, it is more frequent during winter months (Bottomley 1996). Rather

than using the categorical variables full and new moon, a numerical axis, related to the

number of hours and brightness of moonlight during the trapping period, might explain

more of the variance in the trap catch data. Unfortunately, no suitable equipment to

measure moonlight was available during the experiments. While moonlight was shown

to affect the catch of predators, no effects were found for other arthropods, which may

be more sensitive to absolute levels of moonlight.

119

4.3 Patterns of available biomass and diversity of flying Insects

4.3.1 Introduction

While houbara generally eat ground-dwelling insects (see Chapter 2), some taxa that

are unlikely to be sampled by pitfall traps have also been recorded as prey, for

example Orthoptera, Curcuiionidae and Lepidoptera (see Gavrin 1962; Fox 1988;

Collins 1984). Therefore a light trap was used to sample flying insects and to indicate

their seasonal abundance and biomass in Abu Dhabi.

4.3.2 Methods

The light trap

A Heath light trap (as described in Chapter 3) was placed overnight at a sandy location

once every 28 days for two years at five trapping sites (Section 4.1). Traps were

operated on the same dates as pitfall traps, and air temperature and relative humidity

were recorded (see Section 4.1). The invertebrates captured were sorted to order, and

in a few cases to family, and counted. Most of the catch was not identified further, but

a few representative samples were retained for taxonomic reference and are listed in

Appendix 4.1. In addition, the dung beetle Scarabaeus cristatus was recorded to

species level. The catch was oven-dried to constant weight at 60°C to indicate

available biomass of flying insects. However, if examples had been removed for

taxonomic purposes their dry weights were estimated from the remaining data.

Data Analvsis

Trap catch was log-transformed and was found to conform to a normal distribution

using Lilliefors' test. GLM on Systat (Wilkinson 1993) was used to test for differences

in trap catch between the five sites, between months of the year and for the effect of

minimum air temperature on catch. The catch across the five sites was used to give a

monthly mean catch with standard error. However, analyses are limited because there

is only one trap catch per site per month.

1 2 0

Since samples were not identified to species level, two crude measures of insect

diversity were used to test for differences between the sites using GLM: the total

number of insect orders; and the number of coleopteran families recorded per month.

Note that for grouping purposes, the Scarabaeoidea were counted as a coleopteran

family rather than a superfamily.

4.3.3 Results

About 90 000 invertebrates were caught during 24 trapping periods, producing a total

dry weight of about 653g (Table 4.12 and Figure 4.6). Lepidoptera were the most

abundant insects captured and contributed 56.4% by number and 37.4% by dry weight.

Coleoptera were the next most numerous taxa, contributing 19.1% by number and the

highest biomass of any insect order (45.5%). The superfamily Scarabaeoidea were the

most abundant colepterans (13.3%) contributing 42.6% to the total biomass, including

33.7% from S.cristatus a\or\e. Other taxa, such as Diptera, Hemiptera, Neuroptera,

Odonata, Dermaptera, Mantidae, Orthoptera and Araneae, were less numerous,

although larger individuals made significant contributions to the biomass, e.g.

Orthoptera and Hymenoptera. No insects were caught on 1®* March 1995, 29** May

1995 and 27' July 1995 when strong winds overturned the trap.

Figure 4.6 Summary of invertebrates caught in the Heath trap by order. Error bars are

standard errors about the mean for the five sites.

121

Order Family or Superfamily No.caught

% no. Dry weight(g)

% wt

Lepidoptera 50 775 56.4 244.52 37.4Diptera 4 696 5.2 4.86 0.74Hemiptera 8 248 9.2 7.31 1.10Neuroptera Myrmeleonidae 1 552 1.7 17.85 2.30Hymenoptera 7 294 8.1 56.37 8.60Coleoptera Total Coleoptera 17 161 19.1 297.47 45.5

Total Scarabaeoidea* 11 991 13.3 278.46 42.6S. christatus* 388 <0.01 220.20 33.7Curcuiionidae* 22 <0.01 0.35 0.05Cantharidae* 254 <0.01 0.18 0.03Dytiscidae* 4 <0.01 0.18 0.03Histeridae* 55 <0.01 0.53 0.08Bostrichidae* 35 <0.01 0.24 0.03Elateridae* 2 244 0.03 5.98 0.92Other Coleoptera* 2 556 0.03 11.56 1.76

Odonata 6 <0.01 0.72 0.11Dermaptera 26 <0.01 0.84 0.12Mantodea Mantidae 9 <0.01 0.28 0.43Orthoptera Total Orthoptera 194 <0.01 21.21 3.20

Acrididae* 166 <0.01 18.45 2.80Gryllotalpidae* 28 <0.01 2.76 0.42

Araneae 40 <0.01 2.12 0.32

Total capture 90 001 653.55

Table 4.12 Summary of total light trap catch by number and biomass (g dry weight)

over two years. Note that taxa identified by *, are repeated at more than one taxonomic

level, e.g. S. cristatus is listed by order, family and species.

Variations in the number of fivinq insects

The mean number of invertebrates caught in the light trap across the five sites and the

two years showed an annual cycle. Catches were lowest in the winter suggesting a

relationship between the number caught and minimum air temperature, particularly

between November and May (Figure 4.7). Mean summer catches were higher and also

showed greater variance, although the highest mean catch occurred in May, two

months before the warmest time of year.

122

8.5

7.6

6.7

5.8

4.9

4.0

50

40

30

20

10

1 2 3 4 5 6 7 8 9 10 11 12

Month of the year (January=1)

Figure 4.7 Annual cycle of the mean trap catch per calendar month across all sites

(solid line) from two years of trapping, and the mean minimum air temperature (°C)

(dashed line) per calendar month. Error bars are standard errors about the mean.

The GLM for log total catch from the light trap showed significant differences between

catches among different trapping sites and for differences in minimum air temperature

(Table 4.13). However, when calendar month was included in the model there were

significant differences between catches among different trapping sites and months, but

the effect of temperature was no longer significant. This suggests that calendar month

has a stronger effect and can account for more of the variations in light trap catch than

minimum air temperature.

Differences in the size of the light trap capture can be seen in Figure 4.8. The site with

the highest mean catch of invertebrates was Khatam, followed by Medinet Zayed

(Figure 4.8). There were similar mean catches from Baynunah and the Public Hunting

Triangle, while the lowest mean catch was at Um Az Zimul.

123

Source of variation DF F statistic p value

Site 4 7.03 <0.001

Minimum temperature 1 12.03 0.001

Site 4 7.18 <0.001

Calendar month 11 2.24 <0.05

Minimum temperature 1 0.06 n.s

Table 4.13 F statistics for differences in log total invertebrates caught in a light trap at

different sites and at different minimum air temperatures (°C) (n.s. = no significant

difference). Then testing at different sites, different months and for the effect of

minimum air temperatures on catch. Calendar month equals the month in which

trapping took place, from two years of trapping.

8

I 6

5

B P UK M

Trapping Sites

Figure 4.8 Plot of mean and standard error of light trap catch at the five trapping sites

over 24 sampling periods. Sites are K - Khatam, M - Medinet Zayed, B - Baynunah, P -

Public Hunting Triangle, U - Um Az Zimul.

A Fisher’s LSD test was used to examine differences in catches between sites (Figure

4.9). It indicated that there were significant differences between catches at Um Az

Zimul and Khatam, between the Public Hunting Triangle, Khatam and Medinet Zayed,

and between Baynunah and Khatam.

124

U P B M K

Figure 4.9 Differences in log catch at the five sites (post hoc test by Fisher's LSD

paired comparisons). Sites are ordered by abundance (smallest from left to right) and

the ends of each line joins sites that are significantly different at p<0.05 or better. K -

Khatam, M - Medinet Zayed, B - Baynunah, P - Public Hunting Triangle, U - Um Az

Zimul.

Variations in insect diversitv between sites

There were significant differences between both the number of orders of flying insects

and the number of coleopteran families caught between sites (Table 4.14). Calendar

month and minimum air temperature were used as covariates, since they were likely to

influence the number of invertebrates caught in the light trap (Table 4.13).

A post hoc comparison using Fisher’s LSD paired test showed that the number of

orders of flying insects caught at Khatam was significantly different from all other sites

(p< 0.05). This was due to a consistently higher mean catch of insect orders at Khatam

(Figure 4.10). For the number of coleopteran families caught, Fisher’s LSD showed

that Um Az Zimul was significantly different from Medinet Zayed, the Public Hunting

Triangle and Khatam (p< 0.05) (Figure 4.11). The number of coleopteran families

caught at Baynunah was also significantly different from Khatam and the Public

Hunting Triangle (p<0.01). These differences result from consistently low mean

catches in the number of coleopteran families at Um Az Zimul and Baynunah (Figure 4.12).

125

No. of insect orders


Fa c t o r : Site 4 3.72 <0.005

C o va r ia tes



No. of coleopteran families


Fa c t o r : Site 4 5.50 0.001

C o va r ia tes



Table 4.14 F statistics for differences in number of orders of insects and the number of

coleopteran families caught in a light trap at different sites, with trapping date and

minimum air temperate as covariates (n.s. = no significant difference.).

P U M

Trapping Sites

Figure 4.10 Plot of mean value for the number of insect orders recorded by site. Error

bars are standard errors. Sites are K - Khatam, M - Medinet Zayed, B - Baynunah, P -

Public Hunting Triangle, U - Um Az Zimul.

126

U B M K

Figure 4.11 Differences in number of coleopteran families caught at the five sites, with

sites ordered by abundance (smallest from left to right). The end of each line joins

sites that are significantly different at p<0.05 (from Fisher’s LSD test). Sites are K -

Khatam, M - Medinet Zayed, B - Baynunah, P - Public Hunting Triangle, U - Um Az

Zimul.

3.0

I 2,5

1 §K 2,0

f01

u B M K P

Trapping Sites

Figure 4.12 Plot of mean value for the number of coleopteran families recorded by

site. Error bars are standard errors. Sites are K - Khatam, M - Medinet Zayed, B -

Baynunah, P - Public Hunting Triangle, U - Um Az Zimul.

4.3.4 Discussion

Many insects were caught in the light trap over two years. Lepidoptera and Coleoptera

were especially numerous, with the latter contributing a large amount of the biomass

(>46%). There were significant differences in trap catch between months suggesting

an annual cycle, with lower catches in the cooler winter months, similar to the pattern

for ground-dwelling invertebrates (Figure 4.1; Tigar & Osborne 1997).

The highest mean and the maximum light trap catch occurred in May, followed by a

decline in flying insects during the hottest months of the year, although there was

127

considerable variance (Figure 4.7). The catches contained many herbivores, such as

Lepidoptera, Orthoptera and some Hemiptera and Coleoptera, which may have

reduced activity linked with the limited availability of plant foods during the heat of

summer. Insects are poïkilothermie and usually have a body temperature close to that

of their environment (Mordue et al. 1980). However, active metabolic processes,

including flight, generate heat and in warm climates large insects may require rest

periods to avoid overheating (Wigglesworth 1972). The reduction in catch size

between June and October suggests that some insect were trapped less frequently

because they flew for a shorter duration to avoid heat-stress and dehydration. The

highest value for the minimum air temperature recorded during light-trapping in Abu

Dhabi was 34.7°C (August 1995), but maximum daily temperatures for this period

would exceed 50°C (Bottomley 1996). Therefore, during sustained flight large insects

soon reach a lethal body temperature (e.g. 45°C for locusts; Wigglesworth 1972).

The variation in catches between the five sites probably reduced the effect of

temperature on trap catch in the analysis (Table 4.13). The relative abundance and

diversity of invertebrates in light trap catches across sites showed some similarities to

pitfall trap catches (Section 4.1.3). Khatam had the highest mean light trap catch and

the highest measures of diversity of flying insects; while the lowest mean light trap

catch came from Um Az Zimul, the furthest inland and most arid site (Figure 4.7) which

also showed reduced diversity for flying Coleoptera (Figure 4.12). There were

consistently high catches of ground-dwelling invertebrates at Khatam (Section 4.1.3),

although the highest log catch came from Baynunah. The light trap at the Public

Hunting Triangle caught the most coleopteran families, although this result was not

significantly different from Khatam or Medinet Zayed. However, the Public Hunting

Triangle was the most species-rich site for ground-dwelling invertebrates (Section

4.2.3; Tigar & Osborne 1997)

Aerial insects disperse greater distances than ground-dwelling invertebrates, therefore

light traps are likely to sample insects from a greater range than pitfall traps. This may

explain differences between the relative size and diversity of light trap and pitfall

catches at one trapping site. In addition, some of the insects captured in the light trap

are not normally part of the desert community. For example migratory insects, such as

Orthoptera, Lepidoptera, Odonata and Coleoptera, travel thousands of kilometres

across the Arabian Peninsula (Popov 1980; Wiltshire 1990; Walker & Pittaway 1987).

128

Holometabolous insects with aquatic immature stages, such as Odonata and

Dytiscidae, were captured far from any standing water.

A small proportion of the invertebrates in the light trap were predatory (Araneae,

Mantidae and some Hymenoptera), and probably entered the trap in search of prey.

Although ballooning is a well-known method of aerial dispersal in spiders (Wise 1993),

most of the spiders captured were too large to have dispersed in this manner and had

probably climbed into the trap.

One of the aims of this chapter was to look at available prey for houbara. While flying

insects were abundant throughout the year the majority were minute, with a mean dry

weight of <0.01 g, and of little value as food for a bird the size of a houbara. Larger

prey were comparatively rare and only 166 acridid grasshoppers were caught over two

years. Outbreaks of the locusts Schistocera gregaria and Locusta migratoria have

been recorded in the region, but such occurrences are sporadic (Popov 1980).

However, they may be more common in other parts of the houbara’s range such as

Central Asia, where locusts are an important prey (Gavrin 1962). The large dung

beetle S. cr/sfafus frequently occurred in the light trap, but there is evidence to suggest

that even when similar beetles are abundant that they are not eaten by houbara,

although the reason for ignoring such large prey is not clear (Gubin & Mukhina in

prep.). The role of invertebrates in the diet of the houbara is discussed in detail in

Chapter 5.

129

4.4 General Discussion on Abu Dhabi’s Invertebrates

The invertebrate communitv

Previous accounts of invertebrates from Abu Dhabi and UAE have emphasised taxa

from mesic and man-altered habitats (see reviews in Chapter 1; Tigar 1996a & b;

Appendices 1.1 & 1.2). However, desert arthropods are locally abundant and a

frequent component of Abu Dhabi's deserts. Currently, there are 508 records from this

region, of which 303 were found during this study and include 196 new records for the

UAE (Appendix 4.1). Some have yet to be identified to species level, and many more

are undoubtedly awaiting discovery, particularly microfauna (see Zak & Freckman

1991) which were not included in my study.

Large detritivorous tenebrionids formed a major part of the invertebrate community and

49 species or subspecies were recorded (Appendix 4.1). As in other deserts (Holm &

Scholtz 1980; Crawford & Seely 1987) these beetles contributed about one third of the

total desert species in Abu Dhabi (Table 4.7). Tenebrionids, thysanurans and other

omnivores are particularly important in deserts because they recycle energy from

detritus, making it available to organisms higher up the food chain (Seely & Louw

1980). As in other deserts they also contributed much of the biomass (see Crawford

1991).

Predaceous arthropods are another abundant and diverse component of desert

ecosystems, and are more numerous in arid than mesic environments (Polis &

Yamashita 1991). The combination of their physiology, particularly a low metabolic rate

and plasticity of prey choice, allows them to survive conditions of unpredictable and low

food supply typical of deserts (Polls 1991b). In UAE they formed slightly less than a

third of the desert species (Table 4.7), but the taxonomy of some orders, particularly

the Araneae, Mutillidae and other parasitoids, is poorly known and their diversity was

underestimated. The largest arachnids may also have been under-recorded because

they escaped from or avoided capture in the pitfall traps.

Knowledge of Arabian ants continues to improve (Collingwood 1985; Collingwood &

Agosti 1996) and 65 species have been recorded in UAE (Collingwood etal. 1997;

Appendix 4.1). These include 12 species of the genus Cataglyphis\Nh\ch are

structurally adapted for digging in loose sand and are able to survive surface

130

temperatures of 50°C (Delye 1968). However, outside desert locations, Introduced or

tramp species form a high proportion of UAE's ants (about 20%; see Collingwood etal.

1997) and include Solenopsis geminata which is well-known for its deleterious effect

on endemic insects in USA (Williams 1994). Other desert social insects are poorly

known, although there are at least two species of termites (Appendix 4.1). Most ants

and termites live in large colonies and form a high proportion of the desert biomass

(MacKay 1991). They are trophically diverse, although many are detritivores or general

scavengers. In Abu Dhabi ants were the most numerous animals in the pitfall traps.

Aerial insects were plentiful, and included many herbivores especially Lepidoptera, as

well as some predators and omnivores. Studies from North American deserts suggest

that desert-adapted trees and shrubs support a wide variety of invertebrates. For

example, mesquite Prosopis glandulosa has a resident fauna of over 200 arthropod

species which depend either directly or indirectly on the tree for food and shelter

(Simpson 1977; Ward etal. 1977). Each tree acts as a separate habitat patch, and by

moving between different patches herbivorous insects remain persistent at regional

levels in arid environments (Wiens 1976), although at local levels they show

considerable temporal and spatial variation in numbers and community composition

(Wisdom 1991). While native trees are relatively scarce in Abu Dhabi, both trees and

shrubs of Prosopis cinerla and Acacia tortills occur, and are probably used by many of

the aerial insects captured in the light trap for at least part of their life cycle.

Underground herbivory on roots and tubers is another important trophic level in

deserts, where above-ground green plants are scarce and infrequent (Ludwig 1977).

The immature forms of the Cicadidae, Scarabaeoidea, Elateridae and Tenebrionidae

caught in the light trap, are likely to include root and tuber feeders.

Temporal patterns

Both ground-dwelling and aerial insects showed similar patterns of seasonal

abundance (Figures 4.1 and 4.7). Fewer insects were trapped in the colder winter

months, coinciding with the period when rainfall is most likely to occur, although

temperature and rainfall could not be separated in the analysis. Climate-induced

seasonal variations in invertebrate abundance occur in many deserts (Ahearn 1971;

Ayal & Merk11994; Holm & Edney 1973; Seely 1991; Wisdom 1988), and most desert

animals and plants respond rapidly to environmental changes (Polls 1991a).

131

Temporal segregation, whereby different species forage at different times of day, is

thought to allow more species to coexist on the limited food available in deserts. This

has been demonstrated for omnivores, including ants (MacKay 1991) and tenebrionids

(Crawford 1991), and predatory arthropods (Polis & Yamashita 1991).

Spatial patterns

There were differences in the number and diversity of invertebrates at the five trapping

sites. Khatam appeared to have consistently high numbers of invertebrates and the

Public Hunting Triangle was particularly rich in terms of both ground-dwelling and flying

invertebrates, although the reasons for this are not clear. Both biotic and abiotic factors

influence faunal abundance and diversity, and the intensity of grazing is probably an

important factor in Abu Dhabi.

In the Namib Desert, Seely (1991) found that the species richness of ground-dwelling

arthropods on sand depended upon the height of dunes, the ratio of vegetated to non

vegetated surface area, the quantity of detritus and the distance from the coast. The

latter determined the amount of fog, which is the major source of water in this area

with very low rainfall. There were also differences in the faunal composition of

compacted inter-dunes and sand dunes, with similar effects in Abu Dhabi for substrate

(mobile sand or compacted gravel plains). The ever-increasing presence of irrigated

farms and plantations in UAE provides an additional food supply for herbivorous

insects, and may result in many local faunal changes. Invertebrate diversity is also a

consequence of the region's biogeography, with the southern parts of UAE bordering

on Oman containing more elements of the African flora than northern, coastal areas

(Mandaville 1990), which are likely to have their own associated arthropod fauna. Two

sites, Um Az Zimul and Khatam are within 20km of the Omani border, while Baynunah

and Medinet Zayed are coastal and the Public Hunting Triangle is intermediate to both

the coast and the Omani border.

Implications for biodiversitv studies

Biodiversity studies should consider the effect of annual and daily cycles, temperature,

phase of the moon and spatial variation when carrying out surveys. In particular, the

local and regional variation of patchy environments such as deserts demands

132

rigorously designed, randomly-stratified sampling techniques (see Osborne 1991,

1992).

Natural historians often centre their observations in atypical habitats, including wadis,

parks, gardens, irrigated farms, man-made dams and sewage works, where water is

no longer a limiting factor to fauna and flora. While such environments may be useful

for international migrants, particularly birds, the effects of the increasing amount of

mesic areas in UAE on endemic or desert-adapted wildlife are less clear. However, the

ranges of non-desert birds including feral pigeons Columba livia, collared doves

Streptopelia decaocto and house sparrows Passer domesticus have recently expanded

along the tracts of irrigated plantations and by following water transported deep into

the desert for livestock (Osborne etal. 1996). The high proportion of introduced ant

species in UAE (Collingwood etal. 1997), highlights the ease with which small, non

native arthropods can establish themselves. Such minor changes often go unnoticed,

but there are numerous global examples of the devastation to wildlife and agriculture

caused by an accidental or intentional introduction of non-native species (see Mooney

& Drake 1986; Godfrey & Crawley 1998).

UAE is beginning to recognise and value its own fauna and flora (Osborne etal. 1996)

with animals such as the houbara (Bailey & Hornby 1994) and Arabian leopard (Hellyer

1996) acting as flagship species. However, further efforts to understand the natural

history and ecology of the desert should be encouraged. In particular the less

charismatic, arthropod element has largely been ignored and yet forms a greater total

biomass than vertebrates (MacKay 1991 ) and plays a critical role in the cycling of

elements and energy-flow throughout the desert ecosystem.

133

C h a p t e r 5

T h e d ie t o f t h e h o u b a r a b u s t a r d in A b u D h a b i


This Chapter presents information on the diet of the houbara in Abu Dhabi based on

the examination of faeces and gizzard contents. In addition, access to captive birds

enabled calibration trials to be carried out, so that counts of prey remains in faeces

could be adjusted for differential digestion. While emphasis was on animal foods, plant

remains were identified wherever possible and further refinements for dietary studies

are suggested. The reconstructed diet was used to estimate houbara energy

consumption and compared with the actual consumption of an artificial diet by captive

birds .

134

5.1 General Introduction

Our understanding of the diet and feeding ecology of houbara in Abu Dhabi is poor

(see Chapter 2). More precise information will help habitat management in terms of

food availability for over-wintering and captive-bred, released houbara, and may

explain the seasonal distribution of these nomadic migrants across their range. A full

understanding of the diet of wild birds will indicate how the composition of captive diets

can be improved, including the relative proportions of appropriate food types and

nutrient balance. Better enclosures for houbara could incorporate features that attract

or encourage natural foods, thereby increasing available food and providing a more

stimulating environment.

5.2 Quantifying the diet via faecal analysis

5.2.1 Introduction

Houbara eat a variety of animal and plant food, and invertebrates are frequently cited

as important prey (Cramp & Simmons 1980; Johnsgard 1991). The birds feed

throughout the day but are generally crepuscular (Hinz & Heiss 1989) or nocturnal

(Anegay 1994), which combined with their cryptic coloration and extreme wariness

makes observations of foraging difficult to obtain. Most descriptions of the diet are

reports of gizzard contents or chance observations of feeding (see Chapter 2). Only

Collins (1984, 1993) and Gubin & Mukhina (in prep.) have quantified the diet from food

remains in faeces, but neither assessed the destruction of prey during digestion. As

Green & Tyler (1989) point out, avian dietary studies based on faecal analysis must

account for differential digestion or their conclusions may be invalid.

Houbara faeces contain much finely ground material that is difficult to identify and

quantify. To simplify the examination of faeces prey were categorised into functional

groups, which were more relevant to foraging birds than taxonomy (Cooper etal.

1990), and diagnostic fragments were selected for each group (see Ralph etal. 1985;

Moreby 1988). Feeding trails with captive houbara examined the recovery rates of prey

fragments in faeces, and consistent “key fragments" were identified which enabled the

correction of differential digestion and calculation of initial invertebrate consumption.

Basic accounts of plant foods and calculated estimates of houbara energy

requirements were also included. Finally, estimated invertebrate consumption was

135

compared with prey abundance as measured by pitfall traps (in Chapter 4), to try to

address the question of whether houbara are food limited in UAE.

5.2.2 Methods

Calibration experiments with animal prey

Potential prey were identified from the literature (see Chapter 2) and by qualitative

examination of wild houbara faeces and compared to an invertebrate reference

collection. Prey were classified into 16 groups according to their size, daily activity

rhythm, habit, speed and type of locomotion (Table 5.1). Live prey were available for all

trials apart from adult mice which were used as models for desert rodents.

Wild-caught adult houbara that had been in captivity for about 6 years were used in the

trials. Birds only had access to the experimental diet and were kept separately in

rooms which received natural light and were air-conditioned to about 24°C. The birds

were allowed to settle for two weeks before experiments began, and each received

75g of dry food pellets and free access to water daily. Feeding with pellets stopped 12

hours prior to each experimental meal. On the first day of each trial, birds were given a

known number of a single prey group (Table 5.1) together with pellets to a total weight

of 75g. Any uneaten prey were removed after three hours and counted.

On each subsequent day, birds were returned to a diet of 75g pellets. Faeces were

collected every 12 hours for one week and examined for prey remains. A different prey

type was given at the start of each consecutive experiment so that remains from

previous trials could be distinguished. Where possible trials were replicated for each

prey group on 4-5 birds, although lack of available prey meant that not all prey types

could be tested on every bird (Appendix 5.1).

Preliminary work indicated a rapid passage time through the gut (about 4 days, see

Appendix 5.2) and it was assumed that prey fragments not recovered within 14 days

were digested or crushed beyond recognition. Prey remains were removed from the

faeces and their recovery rate was calculated as the ratio of the number recovered to

the number consumed. Means and standard errors (between trials) were calculated

using the formulae for ratios described by Snedecor & Cochran (1967).

Preygroup

Size (cm) Activity regime Habit ' Speed Type of Movement

Taxonomic groups Examples from UAE

1 <0.5 Nocturnal Terrestrial & arboreal

Slow Walk Hymenoptera: Formicidae. Ants Camponotus xerxes

2 <0.5 Diurnal Terrestrial & arboreal

Slow Walk HymenopteraiFormicidae. Ants Cataglyphis spp., Crematogaster spp., Messor spp.

3 0.5-1.5 Nocturnal Arboreal Slow Walk or crawl Coleoptera:Curculionidae, Lepidoptera (larvae)

eg Bothyrideres anxius Ocladius sp., Ammocleonus sp. (Phytophagous insects)

4 0.5-1.5 Nocturnal Terrestrial Slow Walk ColeopteraiT enebrionidae Small ground-dwelling tenebrionids

Mesostena puncticollis

5 0.5-1.5 Nocturnal Terrestrial and arboreal

Slow Walk ColeopteraiT enebrionidae Small arboreal tenebrionids

Tentyrina palmeri

6 1.5-5 Nocturnal Terrestrial Slow Walk ColeopteraiT enebrionidae Large tenebrionids

Blaps kollari, Prionotheca coronata, Pimelia arabica, Ocnera philistina, Akis elevator.

7 1.5-5 Nocturnal Terrestrial Fast Walk Coleoptera: Carabidae Anthia duodecimguttata, Scarifies guineensis8 1.5-5 Diurnal Terrestrial,

arboreal & aerialFast Walk, jump and

flyOrthoptera:Acridida. Sfiort horned grasshoppers and locusts

Schistocerca gregaria, Pyrgomorpha conica, Truxalis procera, Heteracris littoralis.

9 1.5-5 Nocturnal Terrestrial Fast Run Solifugae. Camel spiders Galeodes sp.10 1.5-5 Nocturnal Terrestrial Slow Walk Scorpionae: Scorpions Buthicus yotvatensis nigroaculeatus,

Vachoniolus spp.11 >5 Diurnal Terrestrial Fast Walk Reptilia. Day active lizards Acanthodactylus spp.12 >5 Nocturnal Terrestrial Fast Walk Reptilia. Gekkos and lizards Bunopus tuberculatus, Stenodactylus spp.13 >5 Nocturnal Terrestrial Fast Walk and jump Rodentia: Small mammals gerbil,

and gerboasGerbillus cheesmani

14 >0.05-4 Nocturnal/diurnal

Terrestrial & arboreal

Fast Walk and run Aranea: Spiders (very diverse) Gnaphosidae, Salticidae, Lycosidae, Sparassidae (indeterminate species)

15 2.0-5 Diurnal & Nocturnal

Aerial and terrestrial

Slow - Fast

Fly or walk Flying insects eg Buprestidae, Scarabaeiodea, Lepidoptera

Julodius spp., Julodella spp. Scarabaeus christatus

16 1.5-4.0 Mainly diurnal Terrestrial Slow - medium

Walk, run or “sand swim”

Surface dwelling, diurnal tenebrionids

Erodius spp., Adesmia spp.

Table 5.1. Functional groups of potential animal prey of houbara bustards in UAE. The term terrestrial implies a predominantly ground-dwelling animal, arboreal indicates one that climbs or lives on plants (usually a herbivore), and aerial indicates an active, free-flying insect.

wO i

137

Faecal sample collection from wild birds

Houbara are the largest of three species of three-toed birds in UAE (the others are

the stone curlew and the cream coloured courser) and have a characteristic

footprint. Wintering houbara occur at low densities in Abu Dhabi (Osborne 1996a)

and unlike resident or breeding birds, they do not have regular roost or display sites

(e.g. Collins 1984; Van Heezik & Seddon, in press). Instead houbara move singly

through the desert and faeces were found by walking along bird tracks, which

remain visible for several days on sandy substrates. Faeces were placed in plastic

bags and kept cool until they could be frozen at -5°C.

Faecal analvsis

Defrosted faecal samples were softened in water and teased apart using a glass

rod over a 200 pm sieve to separate out the prey fragments. Irrigated samples were

transferred to a white ceramic crucible and illuminated under short wave UV light,

which causes scorpions to fluoresce (Polis 1990a). Invertebrate fragments were

removed under a binocular microscope, then dried and counted. They were

identified using a reference collection of whole specimens, body fragments and

photos. Descriptions and photos of fragments are given in Appendices 5.3 and 5.4.

Initially, an attempt was made to measure the volume and dry weight of the animal,

plant and inorganic components per faeces, but manual separation proved

incomplete. Then, a rapid, objective and repeatable index for the relative

proportions of food types in faeces using image analysis was considered (Banks

1990; Chesmore & Monkman 1994). However, poor discrimination between the

components combined with high refraction and reflection of light hampered the

technique. Therefore, a visual estimate of the volume of invertebrate as opposed to

plant material in the faeces was used comprising five categories; <5%, 25%, 50%,

75% and >95% invertebrate material. While limited, such methods are widely used

for birds (see e.g. Savory 1989). The identity of plant remains, including leaves,

flowers or seeds, was noted when possible. In addition, a reference collection of

plant epidermes from UAE was assembled, and as a pilot study slide preparations

were made from captive houbara faeces using the technique of Storr (1961).

Although epidermes and hairs were visible, it was not possible to quantify plant

138

remains because animal fragments in the diet obscured many characteristic plant

microstructures (Norton 1995).

Dietary calculations

When calculating a typical houbara diet from faecal remains, it was desirable to

include a measure of the variation of recovery rates between birds. While standard

errors of ratios provide an indication of variation (Snedecor & Cochran 1967), those

based on small samples are often skewed and may be unreliable (Krebs 1989).

Therefore, a Monte Carlo method was used to estimate a confidence interval for the

overall diet. Firstly, the number of key fragments found per prey group from the total

number of faeces (n=161) was averaged. Then, prey intake per prey group was

calculated by multiplying the average number of key fragments by the reciprocals of

the recovery rates. The recovery rates were chosen at random from the actual

values calculated for each trial bird. This process was repeated 1000 times to yield

1000 estimates of the numbers of each prey group eaten depending on variations in

recovery rates. The number of prey eaten was converted to biomass, using mean

weight per taxon, and then to dry weight, amount of fat and protein from published

data on similar taxa (Redford & Dorea 1984; Robel etal. 1995). Calorific values

were calculated assuming 5.306 kcal/g for insects and 5.480 kcal/g for arachnids in

the absence of more specific data (Robel et al. 1995) and corrected for

metabolizable energy (71.2%; Bell 1990). Results from the 1000 simulations were

ranked to identify the median, and upper and lower 95% confidence limits.

Since there was no information on the houbara’s metabolic rate. Resting Metabolic

Rate (RMR) and Active Metabolic Rate (AMR) were calculated using the following

general equations (Bennett & Harvey 1987):

In (RMR) = 0.68 In (body weight) - 0.28

In (AMR) = 0.61 In (body weight) + 1.18

Energy requirements were also calculated from the weight of food pellets consumed

by captive birds between experiments and the metabolizable energy content of the

pellets (2800 cals/g).

139

A typical diet for the houbara was estimated using the number of each food type

that must be eaten to yield daily energy needs (AMR) assuming an intake

proportional to their relative abundance in the faecal samples. As a crude estimate

of how dietary requirements may determine foraging behaviour, the distance that a

houbara must travel to obtain sufficient invertebrate food was calculated by

assuming that houbara encounter food at similar rate to pitfall traps (Chapter 4).

Pitfall capture from the winter months in Baynunah was used to indicate prey

abundance, since over 92.5% of houbara faeces were collected from this region.

5.2.3 Results

Calibration experiments with animal foods

Key fragments were selected for low variance in the recovery rate between birds

and are shown in bold in Table 5.2. Recovery rates for key fragments ranged from

0.21 ± 0.08 to 0.86 ± 0.11 indicating substantial differences between taxa, although

for some prey groups there was little difference between the recovery rate of

several fragments.

Figure 5.1 and Table 5.3 illustrate how key fragments were chosen, using group 6

as an example. Recovery rates for the 13 recognisable fragments ranged from 0.02

(sternites) to 0.51 (tibia). While tibia had the highest recovery rate they also had a

high variance. The next highest recovery rates were for femora and jaws and both

had lower variance than tibia. In this case the larger and more easily recognisable

femora were chosen in preference to the smaller jaws.

0.90 j 0.80 - 0.70 0.60 + 0.50 0.40 - 0.30 - 0.20 0.10

0.00 - 0.10

Î I - , 11 ITarsus Trochanter Elytra Scutellum Sternites Prostemum Labrum Mentum

Figure 5.1 : Mean ratio of recovery rates (filled squares) for fragments from group 6.

The length of the error bars indicate the upper and lower confidence limits.

Preygroup

Genera used in the trails

No. of trials

Head Thorax Femur Tibia Mandible(mouthparts)

Elytra Pincer (pedipalp) (only in (only in arachnids)

coleoptera)

RecoveryRate

SE RecoveryRate

SE RecoveryRate

SE Recoveryrate

SE RecoveryRate

SE Recovery SE Recovery SE Rate Rate

2 Messor 3 0.66 0.119 0.04 0.031 * * *

3 Ocladius 3 0.45 0.187 0.32 0.192 0.56 0.073 0.45 0.76 * 0.21 0.198

4 Mesotena 6 0.63 0.108 0.38 0.156 0.76 0.043 0.71 0.043 0.72 0.098 0.43 0.125

5 Tentyrina 3 0.47 0.257 0.28 0.255 0.63 0.115 0.45 0.128 0.62 0.187 0.29 0.103

6 Akis,Ocnera,Pimeiia

7 0.35 0.081 0.04 0.026 0.38 0.080 0.51 0.136 0.39 0.088 0.10 0.056

7 Anthia 4 0.33 0.125 0.22 0.052 0.81 0.094 0.80 0.098 0.86 0.109 0.22 0.169

8 Orthoptera 5 * * 0.16 0.043 0.12 0.043 0.67 0.178

10 Vachcnicius 5 * * * • 0.04 0.035 0.21 0.07

16 Erodius 3 0.43 0.147 0.04 0.076 0.76 0.126 0.63 0.005 0.72 0.141 *

Table 5.2. Mean and standard error (SE) of the recovery rate for prey remains in faeces with key fragments in bold. Empty cells indicate that the fragment was not applicable to the prey group and * indicates a recovery rate <0.01%. Fragments occasionally found are excluded, e.g. labrum, mentum, scutellum, trochanter, sternum, sternite and tarsus. Vertebrate prey (groups 12 and 13) are excluded because no fragments could be quantified.

Thorax was represented by the propodeum for group 2, and the thoracic disc for groups 3, 4, 5, 6 and 7

Body part Head Femur Jaws Tibia Tarsus Trochanter Elytra Scutellum Sternites Prosternum Disc Labrum Mentum

Correction Factor 2.85 2.63 2.55 1.96 12.33 3.29 9.87 6.17 49.33 14.80 24.67 2.96 5.69Upper CF 1.84 1.75 1.67 1.20 7.40 1.75 4.26 2.46 17.68 5.44 9.90 1.91 3.39Lower CF 6.28 5.24 5.43 5.30 37.01 27.81 -31.35 -12.29 -62.47 -20.49 -50.22 6.61 17.77Mean ratio 0.35 0.38 0.39 0.51 0.08 0.30 0.10 0.16 0.02 0.07 0.04 0.34 0.18SE of ratio 0.08 0.08 0.09 0.14 0.02 0.11 0.06 0.10 0.02 0.05 0.03 0.08 0.0595% upper 0.54 0.57 0.60 0.83 0.14 0.57 0.23 0.41 0.06 0.18 0.10 0.52 0.3095% lower 0.16 0.19 0.18 0.19 0.03 0.04 -0.03 -0.08 -0.02 -0.05 -0.02 0.15 0.06

Table 5.3 The correction factor and recovery rate (mean ratio) for fragments recovered for group 6 (large nocturnal tenebrionids). Mean ratios were calculated according to Snedecor & Cochran (1967). Variance is shown as the calculated upper and lower correction factors (OF), SE = Standard Error about the mean recovery rate, and 95% upper and lower are the confidence limits of the recovery rate.

142

Faecal analvsis

A total of 161 faeces were collected from 52 separate houbara tracks between 18

March 1993 and 3 September 1995 (Appendix 5.5). The mean number of faeces

per track was 3.23 (± 3.22 SD). It was assumed that the faeces originated from a

maximum of 52 birds, but the minimum is not known since birds may have left more

than one track. For comparative purposes dietary composition was calculated for

both number of faeces and tracks.

All faeces contained invertebrate material, and over 72% of samples contained a

volume of at least 50% or more invertebrate remains following digestion (Table 5.4).

About 12% of faeces contained less than 5% invertebrates, although this figure was

inflated by multiple samples from a single houbara track.

Percentage invertebrate material

<5% 25% 50% 75% >95%

Percentage of faeces 11.8% 16.2% 32.3% 36.7% 3.1%

Table 5.4 Estimated percentage of invertebrate matter of houbara faeces from Abu

Dhabi (n=161).

Dipterygium glaucum and a grass were the most frequently eaten plants, with their

leaves occurring in faeces along 24.5% and 18.9% of tracks respectively (Table

5.5). Other desert plants, including shrubs and forbs, were eaten less frequently.

The percentage frequency of prey per faeces was slightly lower than the

percentage frequency by tracks except for group 16, where a single bird inflated the

totals and reversed the trend (Table 5.6). The most frequent prey from the 52 tracks

were group 6 (94.3%), group 5 (92.5%), group 2 (60.4%) and group 4 (32%) which

are predominantly terrestrial, nocturnal invertebrates representing the

ColeopteraiTenebrionidae and Hymenoptera:Formicidae.

143

Plant family Plant name Structurepresent

Percentage frequency By faeces By track (n=161) (n=52)

Capparaceae Dipterygium glaucum flowers 1.2 1.9Dipterygium glaucum leaves 16.1 24.5Dipterygium glaucum fruits 7.5 9.4

Chenopodiaceae Anabasis sp. leaves 1.2 3.8Chenopodiaceae Haloxylon salicornicum leaves 1.9 5.7Cruciferae Farsettia styiosa flowers 6.8 3.8

Farsettia styiosa leaves 6.8 3.8Zygophyllaceae Zygophyllum sp. fruits 0.6 1.9Zygophyllaceae Fagonia sp. fruits 1.9 1.9Rhamnaceae Zyzyphus sp. fruits 0.6 1.9Leguminosae Legume 1 tendril 3.7 7.5

Legume 1 leaves 0.6 1.9Gramineae Grass leaves 16.8 18.9Gramineae Lanceolate leaf leaves 1.9 1.9Unknown 1 Small ovate leaf leaves 0.6 1.9Unknown 2 Unknown fruits 0.6 1.9

Table 5.5 Plant remains identified from wild houbara faeces, listed as percentage

frequency by faeces (n=161) and by track (n=52).

Tiny particles of scorpions were detected by UV fluorescence in faeces (58.5% of

tracks), but no key fragments were recovered and the role of scorpions could not be

investigated further. No mammalian fur or vertebrate bones were present, but

fragments thought to be reptilian scales occurred in one faecal sample. Two

samples contained silken cocoon-like structures, possibly spider egg-cases, and a

single faeces contained fragments of an unidentified hymenopteran and an insect

larva.

The three methods used to describe the amount of each prey group and estimates

of their percentage contribution to biomass, fat and protein are presented in Table

5.7. The percentage frequency of prey in the 161 faeces calculated without

correction for differential digestion was dominated by ants groups 1 and 2 (70.67%),

followed by groups 5 (small plant-climbing beetles, 12.55%), 6 (large, nocturnal

tenebrionids 9.94%) and 16 (diurnal tenebrionids 5.8%) with minor amounts of other

prey.

144

Preygroup

Percentage frequency By faeces By track

Prey name Percentage frequency By faeces By track

1 8.7 13.2 Camponotus spp. 8.7 13.22 52.8 60.4 Messor spp. 51.6 58.5

Cataglyphis spp. 1.2 1.93 10.6 11.3 Bothyrideres anxius 9.3 9.4

Ocladius sp. 0.6 1.9Indet. weevil 1.9 5.7

4 28.0 32.1 Mesostena puncticoiis 4.3 7.5Gonocephalum sp. 1.2 3.8Oxycara sp. 1.2 1.9Indet. tenebrionid (sp1) 1.9 3.8Apentanodes sp. 19.9 24.5Arthrodibius sp. 0.6 1.9Prochoma spp. 4.3 3.8

5 78.3 92.5 Tentyrina paimeri 78.3 92.56 85.7 94.3 Akis eievator 32.9 52.8

Prionotheca coronata 1.9 5.7Pimelia arabica 77.0 90.6Blaps kollari 10.6 28.3Indet. tenebrionid (sp2) 1.2 3.8Paraplatyope popovi 5.0 3.8Ocnera hisplda 1.9 5.7

7 0.6 1.9 Anthia duodecimgutatta 0.6 1.99 0.6 1.9 Solifugid 0.6 1.9

*10 41.6 58.5 Scorpion 41.6 58.511/12? 0.6 1.9 Reptile scales? 0.6 1.9

14? 1.2 3.8 Spider egg-case? 1.2 3.815 13.7 15.1 Buprestid 13.0 13.2

Scarabaeus cristatus 0.6 1.916 28.6 24.5 Adesmia spp. 13.7 13.2

Erodius spp. 14.3 13.2

Table 5.6 Percentage frequency of each prey group by faeces (n=161) and by track

(n=52) with prey identity where known. "Scorpions were detected using UV light and

? indicates probable prey group.

Applying the recovery rates to these figures produced a similar percentage for

group 5 (12.5%), while values were higher for group 6 (15.01%) and lower for group

2 (66.62%). However, both the corrected and uncorrected estimates of prey

numbers differed substantially from the impression of importance given by the

presence/absence (Table 5.6), which were re-scaled to 100 for comparison (Table

5.7). Using this crude estimate of dietary contribution, group 2 was underestimated

(17.17%) whereas groups 5 and 6 were over-emphasised.

J• J

Preygroup

Relative importance in diet based on

presence/absence in faeces

Percentage frequency based on key

fragments

Percentage frequency based on key

fragments and their recovery rates.

Percentage contribution to biomass

Percentage contribution to fat

Percentage contribution to protein

1 2.83 0.23 0.22 0.04 0.02 0.04

2 17.17 70.44 66.62 3.23 1.71 3.11

3 3.47 0.13 0.15 0.12 0.03 0.11

4 9.10 0.84 0.69 0.65 0.66 0.65

5 25.46 12.55 12.50 8.91 9.06 8.91

6 27.86 9.94 15.01 73.61 74.88 73.67

7 0.19 0.02 0.01 0.05 0.05 0.05

9 0.19 0.02 0.01 0.01 <0.01 0.01

15 4.45 0.03 0.03 0.07 0.04 0.12

16 9.27 5.80 4.76 13.54 13.54 13.32

Table 5.7 Comparison of three methods of faecal analysis, with estimates of the percentage contribution to biomass, fat and protein using data from Robel etal. (1995). No remains of groups 8 and 10 were recovered from the faeces, although scorpions (group 10) were detected by UV light.

cn

146

By contrast, the contribution of prey groups to the biomass, fat and protein intake

gives an alternative view. Group 2 (ants) contributed only 3.23% of the biomass,

while groups 6 (large tenebrionids) and 16 (diurnal tenebrionids) made up 73.61%

and 13.54% of the invertebrate biomass respectively. Fat and protein gave similar

results, probably because few taxa-specific values were available to alter the

balance between groups.

Using the calibrated figures for number of prey consumed and published energetic

values. Table 5.8 gives Monte Carlo estimates of the calorific value of the

invertebrate food eaten that resulted in an average faecal sample. The median

estimate was 24.6 Kcal but note that the data were bimodal with upper and lower

peaks at about 24.2 Kcal and 15.0 Kcal respectively.

Kcal

Median 24.640

Lower 95% confidence limit 13.119

Upper 95% confidence limit 28.071

Upper peak c. 24.208

Lower peak c. 14.952

Table 5.8. Calorific value of invertebrate diet corrected for metabolizable energy

content per average faecal sample for wild houbara over-wintering in Abu Dhabi.

Lower and upper 95% confidence limits were obtained from 1000 estimates using a

Monte Carlo method. Note that the data are bimodal hence the upper and lower

peaks occurred more frequently than the median value.

Applying Bennett & Harvey's (1987) formula, the daily energy needs for the RMR of

experimental birds was 99.1 Kcal/day, which compares favourably with 104.7 Kcal,

based on their mean daily consumption of food pellets (37.4 ±13.4g). The calculated

AMR for houbara was 258.2 Kcal/day and based on the median energy value of

prey consumed per faeces (Table 5.8), an average houbara would be expected to

produce 10.48 (9.20-19.68) faeces/day to meet its AMR. Assuming prey

composition in proportion to their occurrence in the 161 faeces the figures suggest

that an average houbara bustard can meet its daily AMR by consuming a mixture of

147

about 671 typical desert invertebrates. This excludes the contribution of plant foods

which is more difficult to estimate. However, a calculation based on the mean visual

estimate of the volume of plant and mean weight of faeces suggests that on

average plant foods provide 1.41 to 3.06 Kcals per faeces (using metabolizable

energy values from Savory 1989). This increases the total energy per bird per day

by between 5.4 and 11 %, but does not take into account the metabolic costs of

digestion or differences in the plant structures consumed.

The percentage contribution of each prey group to the total winter pitfall trap catch

(78 lines of 20 traps spaced 20m apart, excluding taxa that do not appear in the

faeces) is shown in Table 5.9 column three. Comparison with the calibrated

percentage frequency in faeces showed good rank agreement (rg =0.93, p=0.001,

n=7) although the typical diet contained more prey from group 2 and fewer from

group 6 than expected by chance encounters.

Preygroup

Typical daily diet (number of prey)

Percentage frequency of prey in pitfall traps

Estimated foraging distance (km)

2 445 51.94 123 1 0.18 84 8 4.14 35 84 6.84 176 101 33.84 47 <1 0.90 <0.116 20 2.16 36

Table 5.9. On the basis of the recovery rates the typical daily diet has been

calculated as the number of each prey group required to meet energetic needs.

Prey availability was assessed by pitfall trapping and the foraging distance is how

far the bird would need to search to find this amount of prey, assuming it

encounters prey at random.

Finally, the average length of pitfall trap line needed to catch the number of each

prey group required by the bird per day was estimated (Table 5.9). The highest

value (36km) provides an upper estimate of the daily foraging distance assuming

random prey encounters, although houbara are likely to encounter other prey along

the same route. Figure 5.2 shows the seasonal variation in prey abundance (group

148

2, group 6 and total prey) and the relative effort needed to catch that amount of

prey. The latter is scaled to one for the average distance values in Table 5.9. Note

that in February, when prey were least abundant, the effort needed to catch

sufficient invertebrates would be expected to rise by up to 11 times the average

value.

12.0

35(AQ.2

10.0

raQ.° 20 6.0

VQ.&

£1E3Z

4.0

2.0

0.0Oct Nov Dec Jan Feb Mar

Group 2— O- - - Group 6- - - A- • • Total — ■— Bfort

Figure 5.2. Available invertebrate prey (groups 2 and 6 and total invertebrates) and

relative effort required to catch them during the winter months in Abu Dhabi.

5.2.4 Discussion

The relative merits of different dietarv calculations and indices

The percentage frequency of faeces containing a particular prey item based on

presence/absence is the simplest way to describe diets, but gives no indication of

the amount of each food consumed. Counting remains of prey in faeces gives a

measure of the relative abundance of prey in the diet, especially when corrected for

differential digestion. Corrected faecal analysis for houbara in UAE indicated that

they mainly consumed group 2, especially ants of the genus Messor, group 6, large,

ground-dwelling insects such as Pimelia spp. (Tenebrionidae); and group 5, small

plant-climbing insects represented by T. pa/mer/(Tenebrionidae).

149

Uncorrected faecal analysis underestimated group 2 and overestimated groups 6 and

16.

However, diet descriptions based on number do not take into account differences in

size of prey. While over 66% of invertebrates eaten were ants, they contributed only

3.2% biomass, 1.7% fat and 3.1% protein consumed (Table 5.7). By contrast, the

large tenebrionids (group 6) contributed about 73.6% invertebrate biomass. Indeed,

the Tenebrionidae as a whole (in groups 4, 5, 6 and 16) made up 96.7% biomass,

98% fat and 96.5% protein of the invertebrate component of the houbara diet.

The calculated value for RMR was close to the energy value of pellets consumed by

experimental birds, giving confidence to the use of the general formula of Bennett &

Harvey (1987). From AMR an average houbara must consume an average of 671

invertebrates and would produce about ten faeces per day. The estimated number of

prey eaten per day assumes a spread across prey groups in proportion to their

occurrence in the faeces which correlated well with invertebrate relative abundance

along lines of pitfall traps. Apart from an estimated foraging distance of 36km for

group 16, the foraging distances in Table 5.9 are within the daily range for houbara

movements in UAE (Launay etal. 1997; Osborne etal. 1997a & b). The assumption

that a foraging houbara captures prey at the same rate as a passive pitfall trap is

probably an underestimate, although the similarity between the prey frequency in the

faeces and the traps suggest that these birds are generally non-selective. The

exceptions are an under-representation of large tenebrionids, possible due to the

chemical defences of certain species such as Blaps kollari (Walker & Pittaway 1987),

and an over-consumption of ants. This generalist foraging strategy is to be expected

of a large predator in a harsh environment with low prey availability.

Hutto (1990) notes that many studies on food availability are inappropriate because

birds do not perceive prey in the same manner as humans. Houbara are strong flyers

but are generally cursorial and walk great distances unless disturbed (Launay et al.

1997). Therefore a pitfall transect is a fair approximation of how they encounter food

since the probability of capturing invertebrates increases with distance for both

houbara and transects. However, while houbara can choose to remain and feed in an

area where there is a locally abundant prey, such as an ant's nest, pitfall traps may

fail to sample clumped or patchily distributed prey.

150

RMR and AMR have not been measured in bustards, and the metabolic rates of

some avian families deviate from the equation based on body weight in Bennett &

Harvey (1987). This is most noticeable in small passerines, whose metabolic rate is

relatively high for their body weight. The calculated metabolic rates for houbara are

of the same order of magnitude as rates measured in birds with similar body

weights (Bennett & Harvey 1987). Avian AMR also rises in response to the

increased energy needs associated with changes in activity and body condition,

such as growing, moulting, breeding and migration, and during particularly harsh

environmental conditions (see Carey 1996). These factors should be considered if

direct measurements of the houbara’s metabolism are undertaken.

Although the calculations suggest that on an average day a houbara can fulfil its

energy requirements by feeding on invertebrates alone, this is unlikely to be true

throughout the winter. Prey abundance and activity, estimated from pitfall capture,

show marked seasonal variation in Abu Dhabi and are at their lowest in January and

February (see Chapter 4). At this time, the estimated foraging distance for a

houbara to meet daily AMR was about 11 times the average winter distance (Figure

5.2). Translating this figure into the number of birds that an area can support

requires data on renewal rates of prey and prey densities which are unknown.

However, the importance of large tenebrionids as a source of biomass suggests

that their abundance could be a key to the presence of houbara in UAE.

The crude estimate of the energy contribution of plants suggests that on average

they provide a further 5.4 to 11% energy during the winter in UAE. However, exact

nutrient and energy content vary according to plant structure. Herbage is least

nutritious, but new shoots, bulbs, tubers, seedlings and seeds contain up to one-

third of the metabolizable energy of animal prey (Karasov 1990). Therefore birds

must consume larger volumes of plants to get the same energy value from animal

prey. This lower nutrient content is compounded by increased costs of digestion,

including the breakdown of cellulose and the detoxification of secondary plant

compounds (Karasov 1990). Foods that are difficult to digest will also contribute a

higher volume to faeces and gizzard contents, and without calibration the initial

amount of plant material consumed cannot be estimated.

151

Identification of key fragments

Various prey fragments were recovered from faeces and the inherently strong,

chitinous and sclerotized structures survived digestion well. The femur was the most

frequently chosen key fragment, and could usually be assigned to a prey group. For

larger beetles it was better to count femoral joints rather than fragments of femur.

Several authors suggest using mandibles for estimating intake of prey especially

beetles (Moreby 1988; Ralph et al. 1985). For the houbara, mandibles were

applicable for large active prey of groups 7 and 8, while for smaller prey (social

insects like ants) head capsules were better because mandibles tended to remain

inside the head, reducing their recovery rate. Collins (1984, 1993) calculated

houbara prey intake on Fuerteventura on the basis of invertebrate fragments in

faeces, but other than ants these differed from my key fragments. Without trials on

captive birds it is difficult to judge which fragments are reliable and as fragment

recovery rates tend to zero, the differences between corrected and uncorrected

faecal analysis become more apparent.

Problems remain in estimating the role of larger more digestible prey, including

arachnids and vertebrates, because few key fragments could be identified.

Solifugae and Araneae (groups 9 and 14) were not available in sufficient numbers

for the trials, but their chelicerae were used by Gubin & Mukhina (in prep.) and

Moreby (1988) to indicate consumption of solifugids and spiders respectively.

Solifugid presence was indicated by single chelicera in single faeces and gizzards

from UAE, and such prey are unlikely to be active during winter months (Cloudsley

Thompson 1987).

During the calibration trials, pedipalps were identified as key fragments for

scorpions but none were recovered in faeces or gizzards from wild birds. A tail

segment and UV fluorescence were detected in faeces, but since no key fragments

were found scorpions were excluded from the energy calculations. The intensity of

the UV fluorescence might indicate how recently scorpions were consumed. In the

five scorpion trials, fluorescence from a single meal lasted for 4 days (± 0.45 SO),

and the intensity decreased with time. The level of UV fluorescence was less

intense in the wild bird faeces.

152

No key fragments were identified for vertebrates (groups 12 and 13), although fur

occurred in faeces from houbara fed on white mice (see Appendix 5.3). A tooth was

recovered from faeces of captive houbara fed on a mixed diet including mice (S. W.

Warren pers. comm.) and Gubin & Mukhina (in prep.) found a mouse tail and

vertebrae in houbara faeces. However, Nazarov (1992) reported that the faeces of

houbara fed on pigeons and sparrows contained no traces of bone or feather.

Perhaps only larger or older vertebrates resist digestion, which combined with low

and inconsistent recovery rates makes them difficult to detect. No mammalian fur

was seen in wild bird faeces or gizzards from UAE, although one faeces contained

two fragments resembling reptile scales. However, there is little evidence for the

frequent consumption of large prey by houbara in UAE during the winter. How to

account for prey which can be detected through means other than key fragments

(e.g. fluorescence, hair or scales) remains a challenge in quantifying the diet.

Weaker fragments, like beetle elytra, were greatly crushed, and their recovery rates

were either too low or too variable for calibration. However, they helped to

distinguish between structurally similar prey which were grouped separately

because of behavioural differences. For example, T. palmeri (group 5) have slightly

longer femora than M.puncticollis (group 4) and their heads, elytra and thoracic

discs are quite distinctive (see Appendices 5.3 and 5.4). Unlike most ground-

dwelling tenebrionids, T. palmeri has a habit of climbing Haloxylon salicornicum

bushes making it easy to find in the field. This may be related to pheromone

production, since beetles rapidly copulate when collected (personal observation). In

the laboratory T. palmeri ate H. salicornicum, and showed signs of being more

phytophagous than other tenebrionids which are generally detritivorous or

omnivorous.

153

5.3 Analysis of houbara gizzards from Abu Dhabi

5.3.1 Introduction

Gizzard contents have been used to describe the diet of birds including the houbara

(see Mirza 1971; Gavrin 1962), but the killing of endangered species for scientific

study is not an acceptable practice. However, the remains of six birds either found

dead in the wild or hunted by Arab falconers were examined. This small sample

may not be totally representative of the normal houbara diet, but is included here for

comparison with gizzard studies from other regions and with the UAE faecal

analysis.

5.3.2 Methods

Fresh or defrosted gizzard contents were placed in a set of analytical sieves (2 mm

and 210 pm), and irrigated with running water. Most invertebrate material floated to

the surface and was removed using forceps, and the rest was filtered off. All food

remains were dried, identified and counted. In most cases digestion was not

complete, but where prey had been crushed by the gizzard the uncalibrated number

of key fragments was used to assess prey intake since the extent of digestion was

unknown. Plant material was identified and the score system for the proportion of

invertebrate material in faeces was applied to gizzard samples.

5.3.3 Results

A list of plants and animals found in the gizzards and faeces is shown in Table 5.10.

In addition, the contribution of animal prey by group was estimated from the number

of prey and their metabolizable energy content (cals/g dry wt) and compared with

faecal estimates (see Table 5.11). Note that the extent of digestion of prey in the

gizzards was unknown.

The most numerous prey in the gizzards were ants (group 2, 48.9%), diurnal

tenebrionids (group 16, 29.3%) and small nocturnal tenebrionids (group 4,17.4%).

The amount of plant material in the gizzards varied (Table 5.11) and seeds, leaves

and shoots of D. glaucum were the most frequent plant remains (Table 5.12).

154

Animal Family Species name (if known) Prey group Gizzards FaecesFormicidae Camponotus spp. 1 X X

Messor spp. 2 X X

Cataglyphis spp. 2 X X

Curculionidae Indeterminate Curculionidae 3 X X

Ocladius sp. 3 X X

Bothyrideres anxius 3 X X

Tenebrionidae Mesostena puncticolis 4 X X

Gonocephalum sp. 4 X

Oxycara sp. 4 X

Indeterminate Tenebrionidae sp1 4 X

Apentanodes sp. 4 X X

Arthrodibius sp. 4 X

Prochoma spp. 4 X

Zophosis sp. 4 X

Tentyrina palmeri 5 X X

Akis elevator 6 X X

Prionotheca coronata 6 X

indeterminate Tenebrionidae sp2 6 X

Slaps kollarl 6 X X

Pimelia arabica 6 X X

Paraplatyope popovi 6 X X

Ocnera hisplda 6 X

Adesmia spp. 16 X X

Erodlus spp. 16 X X

Carabidae Scarites guineensis 7 X

Anthia duodeclmguttata 7 X X

Orthoptera indeterminate Acrididae 8 X

Solifugidae Galeodes sp. 9 X X

Buprestidae Indeterminate Buprestidae sp1 15 X X

Indeterminate Buprestidae sp2 15 X X

Indeterminate Buprestidae sp3 15 X

Hymenoptera (winged) Indeterminate Hymenoptera 15 X X

Scarabaeoidea Scarabaeus christatus 16 X

Plant Family Species name (if known) Plant partCapparaceae Dipterygium glaucum seeds, stems &

leavesX X

Rhamnaceae Zizyphus sp. fruits & seeds X X

Leguminosae Unknown Leguminosae leaves & tendrils X

Chenopodiaceae Haloxylon salicomlcum leaves X

Anabasis sp.? leaves X

Cruciferae Farsetia stylosa flowers & leaves X

Compositae Unknown Compositae flowers X

Zygophyllaceae Zygophyiium sp.

Fagonia spp. fruits & seeds X

Tribulus sp. leaves X

Unknown Unknown dicotyledon seedlings X

Unknown dicotyledon leaves & fruits X

Gramineae Grass 1

Grass 2 leaves X

Table 5.10 List of animal and plant foods from houbara faeces and gizzards. x =

present. Excludes probable prey from Table 5.6.

155

Prey group Frequency of prey Contribution to invertebrate energy (cals/g dry weight)

Gizzards Faeces Gizzards Faeces

1 0.1% 0.2% <0.05% <0.05%2 48.9% 70.4% 1.9% 3.2%3 1.0% 0.1% 0.2% 0.1%4 17.4% 0.84% 11.6% 0.7%5 0.4% 12.6% 0.2% 8.9%6 1.1% 9.9% 5.0% 73.6%7 0.5% <0.05% 1.7% 0.05%8 0.1% * 0.2% *

9 0.1% <0.05% <0.05 <0.05%15 1.0% <0.05% 3.0% <0.05%16 29.3% 5.8% 76.0% 13.9%

Table 5.11 The percentage contribution of animal prey by group from gizzard

samples (n=6) and estimated energy value (cals/g dry weight) (scaled to 100%) with

comparative values for faecal samples (n=161) corrected for differential digestion. *

Orthoptera not recovered from faeces.

Gizzard Date % volume Plant speciesNo. collected invertebrates

(score) Dipterygium Tribulus sp. Zizyphus sp. Dicotyledongiaucum

1 11/03/95 75 leaves seedlings

2 02/03/95 >953 ??/04/95 50 leaves, fruits

& shootsfruits

4 24/03/94 >955 24/03/94 50 seeds, leaves

& shoots6 unknown 25 seeds, leaves

& shoots

Table 5.12 Score for percentage invertebrate material and identity of plant material

present in gizzard contents, with date of collection if known.

5.3.4 Discussion

As with faecal samples, the number of ants consumed was high but they made only

a minor contribution to energy (1.9%) due to their small size, while larger prey like

156

tenebrionid beetles contributed most energy (group 16, 76%, group 4, 11.6% and

group 6, 5.0%).

Gizzard contents suggest that there may be differences between the houbara diet in

different parts of the range. In Pakistan, between November and January, 52

gizzards contained a mixture of plant and invertebrate material, but plant remains

made up the highest volume of samples (Fox 1988). The six gizzards from UAE had

smaller volumes of plant material, and only one had a higher volume of plant than

animal material (Table 5.12).

Boobyer (1989) separated out and measured the volume and dry weight of the plant

and animal components in 15 gizzards of the Karoo korhaan {Eupodotis vigorsii:

Family Otididae). On the basis of volume he suggests that plant foods were more

important than animal foods for this bustard, but notes that social insects,

particularly Isoptera, were underestimated because of their rapid digestion

compared with vegetative structures. This highlights the difficulty of studying diet

once digestion has started when information on the extent and speed of digestion of

different foods are unknown.

The gizzards in UAE came from dead or hunted houbara whose diet may differ from

that of healthy birds, and any bias will be amplified by the small number of samples.

One gizzard contained about 230 Erodius sp. and little else, and inflated the mean

for diurnal beetles (group 16). It also had gut parasites; 349 Centrorhynchus lancea

(Acanthocephala) and 2 Harteria rotunda (Nematoda) (Jones etal. 1996).

Comparative data on the effect of parasite burden on houbara are lacking but the

body condition of the bird suggested it was in good health. Erodius sp. also

occurred in 14.3% of faeces, but this contrasts with the trials on captive houbara

where Erodius sp. was not always readily consumed (Appendix 5.1). Five gizzards

were collected in March or April and Erodius spp. were most abundant in pitfall traps

between February and June (38 records, representing 108 beetles, see Chapter 4).

The collection date of the sixth gizzard is unknown, but it did not contain Erodius

spp.

157

5.4 General discussion of the diet

5.4.1 Description of houbara diet in Abu Dhabi

A wide variety of animal prey were identified and quantified from faecal and gizzard

contents suggesting that houbara are probably non-selective, simply consuming

locally available prey. Data on plant consumption were limited and there was little

evidence of vertebrate prey, but neither appeared to be major contributors to

houbara energy needs in UAE. Most prey were nocturnal, confirming behavioural

studies of houbara which indicate nocturnal foraging (Anegay 1994; Combreau &

Launay 1997), although large diurnal tenebrionids, such as Erodius spp. and

Adesmia spp. (group 16), were also consumed. However, classing tenebrionids by

their daily activity pattern may not strictly reflect their field behaviour because some

species show variations in seasonal activity, probably in response to temperature

(Holm & Edney 1973). Ward (1991) thought that some tenebrionids increase their

nocturnal activity in response to vertebrate predation pressure and Ayal & MerkI

(1994) reported smaller pitfall catches of tenebrionids following white stork

predation, although this is probably both a behavioural and a numerical response.

Most of the plant and animal remains found in houbara faeces and gizzards have

previously been noted as prey, but a few new coleopteran prey were recorded:

Ocladius sp. (Curculionidae), T. palmeri, Gonocephalum spp., Apentatonodes spp.,

Arthrodibius spp., Prochoma spp. (all Tenebrionidae) and Anthia duodeclmguttata

(Carabidae).

Several houbara faeces and gizzards were dominated by single prey, such as

T.palmeri, Messor spp. and Eroof/us spp., and other authors have noted similar

results (Collins 1984; Goriup & Norton 1992). In Abu Dhabi, houbara may develop a

search image (Tinbergen 1960) for T. palmeri, since these black beetles are highly

conspicuous when climbing vegetation and despite their resemblance to M.

puncticollis, outnumber them by about 41:1 (n=161) in faecal samples. This

contrasts with results from pitfall trapping where M. puncticollis and T. palmeri

frequently occur, and contributed 3.6% and 0.35% to trap catches respectively (see

Chapter 4). However, M. puncticollis does not climb vegetation and is therefore

more likely to be caught in pitfall traps than T. palmeri.

158

Fewer houbara visited Abu Dhabi between September 1992 and March 1996 in

comparison with previous years (Osborne 1991,1992), restricting the number of

faeces collected. A study of houbara in an area with higher densities and/or resident

birds would facilitate seasonal comparisons and sample collection. However, birds

should be marked so that analytical techniques such as compositional analysis

(Aebisher etal. 1993) can be applied to account for repeated measures from

individuals. It may also be possible to measure hormone levels in faeces of

unknown birds and to investigate differences between sexes.

5.4.2 Comparison with other studies on houbara diet

The frequency of prey in faeces and gizzards can be compared with uncalibrated

studies of houbara diet. Collins (1984,1993) found that weevils, tenebrionids and

ants, including Messor maurus, were the most numerous prey in the faeces of

C.u.fuertaventurae, with ants being eaten at times when tenebrionids were not

available. However, his data for weevils were biased because most faeces

originated from two birds (Collins 1984, 1993). In UAE houbara ate similar ants,

probably Messor ebeninus, but weevils were rarely eaten. The latter contributed

only 0.06% to pitfall trap catches (see Chapter 4), and hand searching for prey in

the calibration trials suggests that weevils have a clumped distribution in UAE.

Most dietary descriptions for houbara emphasise large tenebrionids (see Chapter 2)

but in UAE smaller beetles were also important, especially T. palmeri. This suggests

either a difference in the local availability of prey or that smaller species were

overlooked in the past. In Pakistan, Fox (1988) reported large nocturnal and diurnal

tenebrionids of similar genera to UAE including Adesmia spp. and Pimelia spp. in

20% of houbara gizzards. Gubin & Mukhina (in prep.) found few Scarabaeus spp.

beetles in over 1000 houbara faeces from Kazakhstan, and while the dung beetle

Scarabaeus cristatus is common in UAE (Chapter 1 & 4), only one fragment was

found in 161 faeces. Perhaps these beetles are distasteful or their spines make

them difficult to eat. Other studies indicate that Orthoptera are important prey

(Dement’ev & Gladkov 1951), but only one occurred in a gizzard from UAE, where

they are scarce because of the low density of vegetation.

In Kazakhstan, Gubin & Mukhina (in prep) suggest that seasonal changes in plant

phenology are followed by invertebrate and vertebrate population changes (see

159

Chapter 2), and are reflected in the remains of food in houbara faeces. These

breeding birds appear to be mainly opportunistic, but Gubin & Mukhina’s (in prep)

evidence is based on field observation with little analysis, and the frequency of prey

in faeces was biased by multiple samples collected from the display sites of

individual houbara.

Van Heezik & Seddon, (in press) found that the quantity of vegetation rather than

invertebrate availability influenced houbara habitat use in Harrat al-Harrah, Saudi

Arabia. Vegetation density was higher in this stony desert, with a maximum cover of

25% compared with 10% in Abu Dhabi (Roshier etal. 1996). In Saudi, houbara

presence in the dry season was correlated with the plant Capparis spinosa and the

birds were said to feed on its nutritious fruits. This plant does not occur in the sandy

deserts of Abu Dhabi, suggesting a difference in habitat and/or available food.

Combreau & Smith (1997) mention that released captive-bred houbara prefer well-

vegetated areas outside their normal breeding range, and that the availability of

green shoots and flowers influences their choice of habitat. In addition, the density

of tenebrionids and spiders as measured by pitfall traps, was also higher in

houbara-preferred habitats than areas selected at random. Desert tenebrionids are

generally associated with areas of denser vegetation (Ahearn 1971 ; Ayal & MerkI

1994), and phytophagous invertebrates would also be expected to be associated

with their food plants.

Some foods were hard to detect in faeces and could not be quantified, e.g.

arachnids, vertebrates and plants. Pitfall trapping in Abu Dhabi suggests that

arachnids are rarer than tenebrionids and ants (see Chapter 4). In Kazakhstan,

Gubin & Mukhina (in prep.) reported an average volume of 25.8% solifugid remains

in houbara faeces (n=108) in June. Solifugids are probably eaten only when they

are abundant in the summer, and they show little activity during the cooler winter.

5.4.3 Measurement of the relative proportions of food types

Absolute quantification for comparison between plant and animal foods for

omnivores such as the houbara remains problematic. Future studies should

integrate the quantification of animal and plant material. The dietary composition of

herbivorous birds can be quantified by microscopic examination of plant epidermal

remains in faeces (e.g. Summers etal. 1993). However, there are difficulties

160

associated with calibrating the amount of plant material eaten by birds, such as the

accuracy of measuring the amount of growing vegetation consumed and of

selective feeding on leaves, seeds or fruit, rather than whole plants (Owen 1975).

5.4.4 Nutritional and energetic implications

Many past descriptions of bustard diets concentrated on foods that were easy to

identify (see Chapter 2). The calibration of faecal remains by key fragments gave an

objective estimate of dietary composition, and facilitated calculations of the energy

contribution of foods. The calibrations for differential digestion could be applied

across the range of the houbara to investigate regional and seasonal differences,

although local food groups may need to be tested if they differ from the prey in

Table 5.1. These calibrations may even be used as a model for rarer bustards,

which cannot be studied in captivity. Better faecal analysis provides a non

destructive way to gather data on dietary needs of wild birds which, combined with

energetic studies such as the doubly-labelled water technique (Nagy 1983), would

improve our understanding of factors limiting threatened species.

The accuracy of calculations could be improved by using the nutritional value of the

local invertebrates rather than published data. However, Bedford & Dorea (1984)

found little variation in the nutritional quality of different species of ants and termites,

but stressed that the amount of nitrogen (used as a proxy value for protein) per

sample is misleading if it includes indigestible chitin. Rebel etal. (1995) found that

the energy values for similar taxa from different sites varied, probably because of

differences in species composition and life stages, and concluded that field studies

of diet must be more detailed if energy requirements are to be fully understood.

There may also be differences in the micro-nutrients, such as vitamins and

minerals, between taxa which could be especially important for breeding birds and

young chicks. There is further scope for developing work on captive birds, for

instance, in carrying out choice experiments and looking at differences between

individuals by age, sex or breeding condition. A key question might be to test

whether birds offered both invertebrates and vegetation exhibit preferences.

This study focused on the invertebrate part of diet and the energy contribution of

plant foods appeared to be low. However, while some plant parts are more

nutritious other factors also influence the selection of food by animals, especially the

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presence of toxins, repellents and digestlblllty-reducing substances (Crawley 1983).

For example, food choice In seven species of sub-arctic ptarmigan, grouse and

capercaillie bore no relation to energy or nutrition but was negatively correlated with

the amount terpenes and phenolic resins (Bryant & Kuropat 1980). These properties

should also be considered when assessing the suitability of particular plants for

houbara. Grazing pressure from livestock In UAE, and In other parts of the range

affect plant community structure, and overgrazing reduces species richness and

Increases the proportion of grazing-adapted plants, which usually contain high

volumes of secondary plant compounds.

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C h a p te r 6

GENERAL DISCUSSION ON THE ROLE OF INVERTEBRATES IN THE DIET OF THE

HOUBARA BUSTARD


This chapter reviews the main findings of the thesis and the extent to which they

have addressed the principal objectives:

1. To assess the seasonal abundance, distribution and diversity of invertebrates in

Abu Dhabi.

2. To develop a calibrated method of faecal analysis for examining houbara diet.

3. To use the calibration technique on faeces from wild houbara in UAE and to

assess the role of invertebrates in the diet.

4. To establish monitoring techniques for the most important invertebrates.

The relevance of the results is discussed with reference to: the ecology of arid zone

invertebrates; desert food webs; the study of houbara and other avian diets;

conservation of houbara and wildlife in UAE; and implications for houbara captive

breeding programmes.

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6.1 The ecology of arid-zone invertebrates

Seasonal abundance of invertebrates

Pitfall and light traps captured 143,397 invertebrates during two years of monitoring

in Abu Dhabi (Sections 4.1 and 4.3). Invertebrate abundance showed significant

spatial and temporal variation, with fewer individuals caught in the winter than

summer months. Invertebrate activity/abundance as measured by the traps was

positively correlated with temperature and there appeared to be an effect of rainfall

(see Section 4.1 ; Tigar & Osborne 1997). Such patterns of abundance have been

noticed in other deserts, reflecting the abiotic and biotic factors which influence their

fauna (Hinds & Rickard 1973; Thomas 1979; Sheldon & Rogers 1984).

Invertebrates survive the extreme climate typical of arid zones through structural

and behavioural adaptations, and the biology of some taxa, such as scorpions and

camel spiders, makes them particularly well-suited to these environments (see

Cloudsley Thompson 1975 & 1983; Crawford 1981; Polis 1991a).

Both light and pitfall traps provided a measure of adult invertebrate abundance, but

apart from antlion larvae, few immature holometabolous insects were captured.

Many surface-active desert insects, including tenebrionids, are long-lived as adults

but their larvae are subterranean feeding on roots (Seely 1991). We know little of

the life history characteristics that govern the susceptibility and response of

invertebrates to favourable and unfavourable conditions, but Crawford (1991)

suggests that desert detritivores show three types of response to changes in

environmental conditions: short-lived with a rapid, opportunistic response (‘r-

selected' species; MacArthur & Wilson 1967) e.g. collembola, thysanurans, mites,

some beetles and Diptera; long-lived with few tight linkages to environment (‘K-

selected' species) e.g. large tenebrionids (and also large predators such as

scorpions); intermediate often with eusociality (some ants and isopods). The role of

root-feeders, such as immature invertebrates, has rarely been assessed in any

natural environment because they generally remain underground, have a long

development time and are difficult to detect (Brown & Gange 1990). Soil moisture is

probably the single most important factor affecting the survival of underground

larvae, which are particularly vulnerable to desiccation and abrasion (Seely 1991).

Attempts to breed tenebrionids in UAE produced copious larvae, fewer pupae but

no adults (Mitchell 1995). The cause of mortality was not known, although

164

insufficient moisture at a critical stage was probably a contributing factor (M. Seely

in litt.).

Distribution of desert invertebrates

In UAE, the spatial differences in diversity suggested a trend towards a more

impoverished entomofauna for the most inland and arid sites. A similar trend in

invertebrate occurrence with distance from coast occurs in the Namib desert, and is

related to the amount of moisture provided by fog, which decreases further inland

(Seely 1991).

Differences in the diversity between sand and gravel substrates were greater than

differences between geographic sites in Abu Dhabi (Section 4.1). Factors

responsible for these differences include microclimate and habitat requirements, as

well as the dispersal abilities of arthropod species. Substrate characteristics are

particularly important to burrowing animals and factors such as the lability of sand

also determine the ease of root penetration by plants. Thomas (1983) noted

differences in the tenebrionid species on sandy or gravelly soil, with six species

occurring exclusively on sand, three on gravel and five on both, which may be

related to their burrowing abilities. Similar trends occur among arachnid species,

and psammophilic (sand-loving) spiders and scorpions can only burrow on sand

(Polls 1990b). Lamoral (1978) suggests that soil hardness governs the distribution

of species of African Opisthophthalmus scorpions, and has led to spéciation with

extant sympatric species separated by their ability and morphology for burrowing in

hard soils. For non-burrowing species, the availability of refuges with suitable

microclimates may be a limiting factor, e.g. pholcid and theridiid spiders rely on

vacant burrows made by other species (Polis & Yamashita 1991).

In terms of dispersal ability, some predators such as large carabids would be

expected to move further than sit-and-wait predators (some scorpions and spiders).

In temperate farmland, Frampton etal. (1995) found that the dispersal of carabids

varied with habitat, and was more rapid through crops than natural grassland.

Causal effects were thought to include prey availability, cover, plant density and

microclimate. Crist & Wiens (1995) studied and modelled tenebrionid movements in

North American arid-grasslands and found that pitfall transects had high probability

of capturing transient individuals from open population structures. Such effects are

165

likely to have influenced the arthropods captured in pitfall traps in Abu Dhabi

(Chapters 2 & 4).

Diversity

The current study increased the records of invertebrates in UAE by over 38% to 508

recognisable species, subspecies or genera (Appendix 4.1; Tigar 1996a). The new

records included many ants and tenebrionids, which were frequently caught in pitfall

traps and had previously been little studied. Base-line data have been published

(see Tigar 1996a & b; Tigar & Osborne 1997; Collingwood etal. 1997) and a

reference collection has been established to facilitate further research.

Deserts are often thought to show poor species diversity (Noy-Meir 1974; Polis

1991a), although certain taxa, particularly ants, tenebrionids and some predatory

arthropods are considered to be more numerous and diverse in deserts than more

mesic environments (see reviews in Cloudsley Thompson 1991 & 1996; MacKay

1991; Crawford 1991; Polls & Yamashita 1991). The comparison of community

composition between deserts is difficult because of the varying amount of effort

(time) and sampling methods used by different authors, and is exacerbated by

confusion over taxonomic resolution. Records for Abu Dhabi suggest that the

Formicidae (Hymenoptera), Sphecoidea (Hymenoptera) and Tenebrionidae

(Coleoptera) are the most diverse taxa, with 65, 115 and 65 species or subspecies

respectively (Appendices 1.1 & 4.1). However, in the case of Hymenoptera in UAE,

this also reflects current enthusiasm among collectors, and much of this information

was collected in surveys for single taxa (see Hamer 1986a & b, 1988; Guichard

1988 a & b, 1989 a & b, 1993; Collingwood 1985,1988; Collingwood & Agosti 1996;

Collingwood etal. 1997).

Nevertheless ants play important and diverse roles, and because of their colonial

nature they contribute a major part of the biomass in deserts (MacKay 1991). This is

also true in Abu Dhabi, where ants were the most numerous taxa caught in the

pitfall traps (Section 4.2) and found in houbara faeces and gizzards. Of the less

well-known Hymenoptera, the Mutillidae were particularly numerous in pitfalls and

light traps, suggesting that these parasitoids exert a heavy mortality on their hosts

(probably other Hymenoptera; Richards & Davies 1980). Other predatory arthropods

are well-represented in deserts compared with more mesic habitats (Polis &

166

Yamashita 1991), and data from other regions suggest that solifugid and spider

diversity were either under-sampled or underestimated in the present study (see

summary in Polis & Yamashita 1991). Many UAE specimens cannot currently be

determined beyond family or genus. However, eight species of scorpion were

identified (Appendix 4.1), which falls within the range for deserts (mean = 7.1 ± 2.5

SD in Polis & Yamashita 1991).

Faunal comparisons and the description of new species provide much of the

impetus for taxonomic studies (see Fauna of Saudi Arabia series). However, a

fauna for which only incomplete taxonomic keys exist, and where within-species

variation and sexual dimorphism are frequent (e.g. Tenebrionidae; Boorman, J. pers

comm.; Hymenoptera and Orthoptera; Richards & Davies 1980), presents a

challenge to the non-specialist. Collaboration between taxonomists and researchers

is vital, and species lists and descriptions must be published. Both Polis (1991c & d)

and MacKay (1991) note that the current unfashionable status of taxonomy

hampers many lines of research on ecological theory in arid zones.

By understanding the characteristics of a species, particularly life history and

autecology, and the heterogeneity of environment it is possible to predict broad

scale patterns of species abundance. Wiens (1976) even suggests that the spatial

and temporal heterogeneity of deserts can result in a higher species abundance

and diversity than in more uniform environments because competing species co

exist in different habitat patches. In addition, differences in adaptation to host-plant

chemistry and plant architecture influence the number of herbivorous species

occupying a plant (Lawton 1983; Strong etal. 1984; Wisdom 1988). Grazing by

livestock has a considerable effect on both the architecture of woody plants and

plant community composition (Thalen 1979; Floret 1981; Oatham 1996).

In North America, there is good knowledge of the invertebrates associated with

particular plants, e.g. Prosop/s trees (Wisdom 1991) but most Arabian studies have

considered either insects or plants in isolation (Oatham 1996; Roshier et ai. 1996;

see also Fauna of Saudi Arabia series). Broader ecological studies linking animal

communities with the underlying distributions of plants will lead to a greater

understanding of general underlying ecological processes. Geographical

Information System (GIS) in combination with robust analytical techniques such

GLM, would provide powerful tools for hypothesis testing. Deserts also provide good

167

places to study and test metapopulation and patch dynamics (see Hanski 1991 ;

Wiens 1976 & 1985), with the relatively stable microhabitats provided by perennial

plants and burrows acting as refuges from physical conditions and poor food

availability, connected to similar habitat patches via dispersal.

Permanent study sites, like the Coachella Valley in California (Polis 1991b & d),

emphasise the value of long data series, where each researcher has added to the

layers of ecological information. Indeed, short-term studies in stochastic

environments may be highly misleading since annual variations in biological and

climatic data are a characteristic of these ecosystems. In Abu Dhabi, Baynunah is

emerging as a potentially useful study site, and baseline data on invertebrates,

houbara and other fauna and flora have been published (Osborne 1996a; Osborne

et al. 1996; Oatham 1996).

6.2 The desert food web

Polis (1991b & d) provides an example of a desert food web (see definition in

Lawton 1989) from Coachella Valley based on a 20-year data set and about 820

publications. This web is complex because of two factors: the diversity of

interactions, and omnivory. Indeed, Polis suggests that many published food webs

are incomplete because of poor taxonomic discrimination and an inadequate

knowledge of trophic interactions, features also recognised by Pimm etal. (1991)

and Cohen etal. (1993).

Apart from the houbara (Chapter 5), the Abu Dhabi study was not designed to

investigate trophic relationships, and taxonomic discrimination was a problem for

some groups. However, a few observations of feeding were noted for arthropods

(Table 6.1), and most are typical of desert interactions although the laboratory and

pitfall observations should be treated with caution. In the absence of better data, it

seems likely that a web for Abu Dhabi would show much of the complexity of the

Coachella web, although the species would be different. Indeed, it is hard to

compete with Polis’s (1991b) observations of 2,000 man-hours in the field for a

single scorpion species.

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Trophic relationship Species (Order or Family)

Food Source Type of observation

Coprophage Scarabaeus cristatus (Scarabaeidae)

Camel dung (provisioning for nest)

Field

Detritivore/Omnivore Mesostena puncticolis (Tenebrionidae)

Lab diet Lab

Pimelia arabica (Tenebrionidae)

Lab diet Lab

Ocnera philistina (Tenebrionidae)

Lab diet Lab

Blaps koiiari (Tenebrionidae)

Lab diet Lab

Herbivore-host plant Tentyrina palmeri (Tenebrionidae)

Haloxylon salicornicum (Chenopodiaceae)

Field & lab

Granivore Messor sjpjp. (Formicidae)

Seeds {Tribulus sp.?) Field

Predator-prey Apistobuthuspterygocercus(Scorpiones)

Scarabaeus cristatus (Scarabaeidae)

Field

Galeodes sp. (Solifuges)

Various Acrididae Field & lab

Mesostena puncticolis (Tenebrionidae)

Isoptera Field (under wood)

Scarites guineensis (Carabidae)

Bunopus tuberculosis (Reptilia)

Pitfall trap

Scarites guineensis (Carabidae)

Erodius spp. (Tenebrionidae)

Pitfall trap

Cannibal Mesostena puncticolis (Tenebrionidae)

Mesostena puncticolis (larva) (Tenebrionidae)

Lab

Cannibal/detritivore Mesostena puncticolis (Tenebrionidae)

Mesostena puncticolis (Tenebrionidae)

Lab



Lab



Lab



Lab

Intra-guild predation Scarites guineensis (Carabidae)

Parabuthus liosoma (Scorpiones)

Pitfall trap

Galeodes sp. Mantidae LabNecrophage Anthia

duodeclmguttata(Carabidae)

Chicken (Aves) Field

Scarabaeus cristatus (Scarabaeidae)

Gerbilus cheesmanii (Rodentia)(provisioning for nest)

Field

Table 6.1 Trophic relationships in Abu Dhabi (excluding houbara). Cannibal/

detritivores may have been scavenging on dead or dying insects rather than

depredating them. Laboratory diet: rolled oats, dates, almonds and carrots.

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Polis’s suggestion that omnivory is a common feature of desert animals is

supported for many vertebrates (Wiens 1991), including the houbara, and

invertebrates (Seely 1991; MacKay 1991; Cloudsley Thompson 1996). Desert

arthropods may be more generalised and opportunistic in prey choice compared

with those of mesic environments, increasing the likelihood of interactions between

species. For example, there are many records of intra-guild predation in deserts

(Polis & Yamashita 1991). Spiders, solifugids, scorpions, mantids and reduviids

conform to this pattern; they are resource generalists and are frequently intolerant

of each other. Parasitism and hyper parasitism also occur, and predatory

arthropods are hosts for many parasitoids, e.g. during winter in the Chihuahuan

desert pompilid wasps consumed up to 65% of the population of the spider

Geolycosa rafaelana, although this dropped to <5% in summer (Conley 1985).

Temporal variations in desert food webs are also apparent and age structure is

particularly important (Polis 1991b & d). Age-dependent mutual predation is a

common occurrence, and while immature scorpions eat different and smaller prey

from adults, they are themselves subjected to intra-guild predation or cannibalism

by larger scorpions. Some authors suggest that loops in food webs, where species

A eats B, B eats C, and C eats either B or A, are unlikely events in the real world

(Pimm 1982). Again this is refuted by numerous examples in Polis (1991c). In Abu

Dhabi, laboratory observations of Galeodes sp. suggested intra-guild predation on a

mantid, and cannibalism of larvae by adult M. puncticolis. Intra-guild predation of a

small scorpion by the large carabid Scarites guineensis was observed in a pitfall

trap, while two tenebrionids, M. puncticolis and T.palmeri, which were assumed to

be detritivorous, showed predatory and herbivorous tendencies (respectively) in the

field.

Other generalisations about food webs, such as short linkages between trophic

levels, do not apply to the Coachella web which generally has long linkages

(between 6 and 11), often lengthened by soil biota interactions. Polis (1991d)

includes all possible linkages, even rare observations, because he argues that

without a thorough understanding of the diet of a species we cannot recognise

unrepresentative foods. Such information is usually lacking and some food webs

may simply be incomplete.

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Certain features of deserts, including relatively high proportions of arachnids and

other predators, significant temporal and spatial stochasticity with pulses of food

and incoming migrant or nomadic animal populations, may result in more flexible

species interactions, with food webs that are more complicated than those of mesic

environments. The question of whether desert webs are unique can only be

resolved by further research, using standardised methods as advocated by Cohen

etal. (1993).

6.3 Studying houbara and other avian diets

The method for faecal analysis developed using captive houbara was successfully

applied to food remains in faeces of wild birds, and provided a calibration for the

differential digestion of prey (Chapter 5). The use of a standard technique based on

key fragments enables faecal analysis to be carried out more quickly and

objectively. However, if novel foods are suspected in different parts of the houbara’s

range further calibration trials should take place to identify appropriate fragments.

When studying the diet or foraging tactics of animals it is important to understand

how they choose prey. The prey groupings based on body size, speed and mode of

locomotion (Table 5.1) worked well on the faecal samples. Some groups were more

taxonomically diverse than others, but such groupings are justified because birds

are unlikely to discriminate on taxonomic features alone (Cooper etal. 1990).

Indeed, prey location and size are more likely to be used by birds to judge the time

needed to capture prey and prey energy content (Maurer 1990). Avian vision is

different from our own and in addition to the human range of vision, birds can see

well in the UV spectrum (Bennett & Cuthill 1994), which they use during mate

choice (Bennett etal. 1996). Birds may also find prey using UV (see raptor foraging;

Viitala etal. 1995), and this may affect food choice in the houbara, although the

most likely candidate prey, scorpions which show UV fluorescence, are active

nocturnally when natural UV light is low.

The role of plant material in the houbara diet should also be investigated further.

The recommended method is the microscopic examination of epidermal layers

across a slide transect (see Summers etal. 1993; Section 5.2), which is less

subjective than examining whole plant remains.

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Faecal analysis is not without its problems (see Section 5.2), but providing it is

calibrated, it is the best technique for studying the diet of wary and endangered

birds including the houbara and other bustards. Gastro-intestinal flushes (Major

1990), emetics and ring-collars have been used to study avian diets (see review by

Rosenberg & Cooper 1990) but are only suitable for smaller and more common

species. The effort and risk in catching bustards is great, and may result in their

death or a non-fatal injury, including capture myopathy (Windingstad etal. 1983).

This is a temporary paralysis affecting long-legged birds, which prevents them from

standing or walking. Any injury caused during catching would render a wild bird

more vulnerable to predators.

The estimate of energy consumption provides a guide to houbara metabolic needs,

but is not a direct measure. Bryant & Tatner (1991) examined variations in energy

expenditure of birds with body masses at least an order of magnitude less than the

houbara (from 9.5 to 143.4g) and suggest that it is unwise to assume the costs of

one species apply to another. They found that different factors were correlated with

energy expenditure in different species, although flight and brood-provisioning were

common causes of increased energy expenditure. However, other authors have

proposed general equations for energy consumption in birds (Kendeigh etal. 1977),

and provide examples for different bird taxa including passerine or non-passerines;

and during different periods or conditions which influence energy expenditure:

migration, reproduction, moulting, extremes of temperature, changes in

photoperiod, wind velocity, insolation, radiation and other environmental factors (see

reviews in Carey 1996). Adaptation to local climate is important, with desert and

tropical species generally having a lower metabolic rate than related birds from

mesic environments (Ricklefs 1996). Ideally, the estimate for the houbara should be

tested using the doubly labelled water technique (Nagy 1983).

Much of the work on energy expenditure centres on critical values for the

reproductive cycle of birds (e.g. Martin 1987; Carey 1996). Nesting and brood-

provisioning are very energy-intensive processes, and altricial birds may desert the

nest if they lack sufficient energy reserves. The breeding strategy of precocial birds,

such as the houbara, avoids this risk since their young feed themselves from a very

early age. However, precocial birds may require more energy prior to the breeding

season, because their eggs are larger and their yolks have a higher calorific value

than those of altricial birds. Therefore, the over-wintering period in Abu Dhabi may

172

be important in preparing houbara for the following breeding season in Central Asia.

Houbara are long-lived birds and may delay breeding or wait until the following year

if their energy reserves are too low. Any work on energy expenditure or food

limitation would do well to examine resident houbara first, before considering the

costs of more complex migratory birds.

Models of foraging theory hâve been applied to many birds, with varying success

(see reviews in Stephens & Krebs 1986; Stephens 1990). The theory assumes that

animals will act economically and choose feeding strategies that yield more food, or

another currency such as energy or protein, in less time. The functional response of

predators to their prey changes as prey abundance increases, and smaller less

profitable prey may only be eaten when sufficiently common, e.g. in a clumped

distribution (Caraco etal. 1980). Such a strategy could occur in the houbara in

response to social insects or locust swarms, which may only be included in the diet

when sufficiently numerous (note the distribution of Messor spp. ant remains in

houbara faecal samples; Chapter 5). Prey selection in omnivores has been largely

ignored or considered as intermediate between carnivores and herbivores, since

omnivores consume both high-quality animal prey and lower-quality plant foods

(Westoby 1978). Carnivores are thought to be constrained by the search and

handling time needed to obtain prey, while herbivores are constrained by their need

for a nutritionally balanced diet (Pyke 1984). Ball (1994) provides an excellent

account of foraging theory for an omnivorous, diving duck (the canvasback Aythya

valisineria) which did not conform to an energy-maximisation model when tested

with four foods. He suggested that size, texture and perhaps taste were more

important in prey choice than energy (some ducks even rejected prey they had

caught by spitting it out!). However, this situation is more complex than foraging in

the houbara, because of the high energetic costs of diving.

6.4 Houbara diet in UAE

Houbara are omnivorous, with invertebrates making up much of the bulk and most

of the energy of UAE birds. The most important prey were ants in terms of number,

and tenebrionid beetles in terms of total biomass and energy contribution. Bustards

are directly exposed to the same environmental stresses of desert life as their

foods, and by eating insects which have a high water content compared with seeds

173

or dried plant-parts, they avoid the need for supplementary water, although they

drink when in captivity on an artificial diet.

The use of different methodologies, each with their own inherent biases, make it

difficult to compare between studies from other parts of the houbara’s geographic

range (see Chapters 2 & 5), although Fox’s (1988) work suggests that more reptiles

are eaten by C.u.undulata in Morocco. Future work should look at the pattern of

foods eaten by houbara, to see whether they respond to differences in locally

abundant foods or consistently choose particular food types across the range.

Why do houbara occur in UAE when their principal food, invertebrates, is least

abundant, indeed most foods are at their least abundant? The answer may lie in

their breeding grounds in Central Asia rather than Abu Dhabi. The former frequently

experience sub-zero temperatures with deep snow-cover (Osborne etal. 1997a & b)

and it may be more profitable in terms of energy gain to migrate to Arabia where the

winters are less extreme and food is available. In addition, the high summer

temperatures experienced in Abu Dhabi may be too stressful for houbara.

An alternative hypothesis is based on the “source-sink” model of den Boer (1968).

Perhaps the resident, breeding, Arabian houbara in Oman and Saudi are source

populations which quickly fill vacant habitat patches where food availability is not

limited. Any excess birds might then become a sink population, occupying sub-

optimal habitat patches, and perhaps becoming nomadic or migratory across

Arabia. Indeed, Seddon & van Heezik (1995) suggest that the houbara population in

the Harrat al-Harrah reserve in Saudi Arabia is boosted by seasonal migrants,

although their origin is not known. The migration route of houbara over-wintering in

UAE to their breeding grounds in Central Asia has only recently been confirmed,

and is based on a few individuals (Osborne etal. 1997a). We know nothing of other

migration routes or whether there is any interchange of genetic material between

houbara populations in the Middle East. Such work would involve satellite-tagging

wild birds and genetic analyses to examine the relatedness of populations, which

would require capturing houbara and therefore carry an inherent risk of mortality

(see Section 6.3).

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6.5 C onservation o f H oubara and w ild life in UAE

The houbara is a useful flagship species for the desert. Planning for its dietary

requirements and need for undisturbed areas with reduced human activity and

grazing pressure would also benefit other wildlife, although long-term habitat

management may benefit from controlled grazing (Oatham 1996). Most of Abu

Dhabi's desert is open-access, apart from urban areas, private estates, oil-fields,

forestry plantations and a few military zones. The need for protected areas has

been recognised but to date, none have been designated (Osborne & Hornby

1995). The successful functioning of protected areas requires strong political will

and financial commitment, and lessons from other areas suggest that grazing and

hunting rights may be a cause for particular concern in the Middle East (Child &

Grainger 1990; Seddon etal. 1995). The potential harmful effects of development

and environmental change have attracted growing recognition in UAE and in 1993

the Federal Environmental Agency was established (Anon 1993b).

Nomadism is often considered a characteristic of desert birds, which move in

response to changes in food availability (Wiens 1991), and the houbara’s long and

short-distance movements are probably responses to local environmental

conditions. Historical records of resident-breeding houbara in UAE may reflect

previous eras when rainfall was more frequent (Thesiger 1959). The mobility of

birds allows them to exploit differences in habitat and micro-habitat patches in all

deserts such as potential food supply, nest sites etc.

In view of the increasing pace of development in UAE (Oatham 1996; Collingwood

etal. 1997), it would be wise to monitor environmental change. Much of the recent

interest in wildlife has centred on houbara and other large vertebrates (Hellyer

1996; Aspinall 1996). However, within the UK, Lawton (1996) noted that while birds

were useful flagship species, they were not good indicators of species-rich sites of

high conservation value for other taxa. Elsewhere, ants have been used as

indicators of habitat quality and biodiversity (Perfecto & Snelling 1995; Bestelmeyer

& Wiens 1996; Majer & Beeston 1996) and would be a useful Arabian group

because they are well known, easy to collect and are speciose with considerable

variations in habitat requirements. Majer & Beeston (1996) noted that ant diversity

in Australia was reduced by road construction, and to a lesser extent by agricultural

175

development, urbanisation and rangeland grazing. In UAE, Collingwood etal.

(1997) noted that 14 of the 65 species of ants collected were tramp species,

including several cosmopolitan pests and a fire ant Solenopsis geminata. The latter

is of particular concern because of its deleterious effect on native fauna and flora

following an accidental introduction into North America (Williams 1994). Similarly,

the distribution of other typical desert arthropods, such as scorpions, camel spiders

and tenebrionids, might provide useful indications of habitat quality once their

biology and taxonomy are better known.

The only note of caution is that the perception of biodiversity varies according to the

taxa being considered (Gaston 1998). Indeed Gaston found little evidence of either

congruence in geographical hot spots among different taxa, or strong correlations in

biodiversity between different groups across multiple areas. While measures of

biodiversity are highly variable, it is often the less popular taxa, such as

invertebrates, that are ignored in conservation plans (Sutherland 1998).

6.6 Implications for captive breeding programmes

Houbara have been successfully reared at Taif, Saudi Arabia, and released into a

protected reserve, Mazhat az-Sayd (Seddon et al. 1995). However, this was not

without high initial mortality, thought to be due to predator-naive birds being taken

by foxes. Other factors may also have influenced predation, including food

availability away from supplementary feed sites and irrigated plots. Naïve houbara

in poor condition would, according to state dependent foraging, feed in areas and at

times with a high risk of predation (see McNamara 1990), and the foxes may have

responded to this. Foxes may also have scavenged from the carcasses of houbara

that had died of other causes, including starvation.

Evidence from this study (Chapter 5) and other authors (Anegay 1994; Combreau &

Launay 1997) suggests that houbara forage nocturnally, particularly around a full

moon. However, captive birds are generally fed in the morning, when bird keepers

in UAE start work. A change in feeding-times to late afternoon would allow houbara

to forage around dusk, in tune with their innate behavioural rhythms. Indeed,

Hermans (1988a) remarked that much of the food given to houbara at Taif was not

eaten, and soon became rancid and unpalatable to the birds. Fresh foods, including

mince, apples and lettuce, are mixed with moistened food pellets and given to

176

houbara in UAE where unless they are eaten Immediately they soon become

spoiled (personal observation). Artificial lighting might also be beneficial to houbara,

particularly during the summer when the birds could feed nocturnally and avoid heat

stress.

The planting of alfalfa in houbara aviaries is already general practice, and is doubly

effective since it provides a source of fresh green material and herbivorous insects,

such as grasshoppers and weevils, which houbara readily hunt (A. Owen pers.

comm.). In addition, a native plant of the UAE Dipterygium giaucum occurred in

both faecal samples and gizzard contents. Attempts to cultivate and encourage this

plant would be beneficial in both aviaries and areas where houbara over-winter, or

for houbara release sites.

6.7 Conclusions

This study has answered its primary objectives as far as possible. It has provided

information on invertebrate diversity, as well as data on general trends in the

abundance of desert invertebrates. The diet of the houbara was determined using a

calibrated faecal analysis and the examination of uncalibrated gizzard contents.

Houbara take a wide variety of food and invertebrates, especially tenebrionid

beetles, make up much of the bulk in Abu Dhabi.

177

Epilogue

Two main themes run through the thesis; variations in the abundance and diversity

of desert arthropods, and the diet of the houbara. However, abiotic factors of the

desert explain much of this variation. In his classic work “Arabian Sands”, the great

explorer Wilfred Thesiger tells of his travels with the bedu of Abu Dhabi and his

respect for their nomadic way of life. On many occasions, the lives of Thesiger and

his companions were dependent upon the bedu's ability to find the scarce grazing

for their camels. I end with a quote in which Thesiger ponders the question of how

life arrives at isolated habitat patches (Thesiger 1959).

“Four hours later we came to large red dunes set close together. There were green

plants growing there as a result of heavy rain which had fallen two years

before \Ne camped In a hollow and loosed our camels to revel among the Juicy

shrubs.

Larks were singing round our camping place. Butterflies flitted from plant to plant.

Lizards scuttled about, and small black beetles walked laboriously across the

sand. still marked where jerboas and other small rodents had scampered about

during the night. I wondered how they got here, how they had located this small

green island. In the enormous emptiness which surrounded it.”

178

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Appendix 1.1

A preliminary assessment of the arthropods of Abu Dhabi

by Tigar, B. J. (1996a).

In: Osborne, P. E. (ed) Desert ecology of Abu Dhabi- a review and recent studies,

pp 172-195. Pisces Publications, Newbury, UK.

RECORDS OF ARTHROPODS occurring in the UAE, particularly Abu Dhabi, are very few, rcHecting the general lack of knowledge of invertebrates in the Middle East. This makes it impossible to compile an authoritative account of the arthopods of Abu Dhabi at the current time. The majority of records that have been published within the last IS years are based on data collected during scientific expeditions to the neighbouring countries of the Kingdom of Saudi Arabia and the Sultanate of Oman. Where no records exist for UAE, these data have been used to suggest which arthropods may occur in Abu Dhabi based on their occurrence in similar habitats elsewhere.

The taxa that occur most frequently in the desert ecosystem and form the highest biomass are from the classes Arachnida and Insecta. The arachnids are mainly represented by the orders Scorpiones, Solifugae and Araneae, and the insects by the orders Colcoptera (especially the Tenebrionidae and Scarabaeidae), Hymenoptcra (family Formicidae) and the Orthoptera. The ability of desert arthropods to survive the harsh climatic conditions prevailing in Abu Dhabi is discussed in general terms but there remain many arthropods that play an important role in the desert ecosystem about which little is known.

206

C H A P T E R 10

A preliminary assessment of

the arthropods of Abu Dhabi

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- 207 -

E n t o m o l o g y in A rab ia

IU irtiker( IVSO) has rc\ icw c il rhe work ol I he pioneering explorers w ho made mention o f the fanna and flora o f the Arabian Peninsula in their aeeoiints. The first o f these was Ihn Battuta, a merchant, scientist and Islamic pilgrim from Tangier, w ho tra\ elled extensi\e ly in the Middle and Far East as well as Russia laetween 1525 and 135.5. H ow e\ er. the most notable from the point o f \ iew o f collecting and recording art hropods were St John Philby. Bertram 'I'homas and W ilfred Thesiger. P iiilby made many expeditions to the Arabian Peninsula from 1917 until 1953 and collected a considerable qnantity o f material that is hon.sed in the Natural H isto iy Museum in London. The material has been poorly w orked. howe\ er. and no com plete lists or articles ha\ e e\ er been ])tiblished from his specimens. Similarly. Thomas collected in,sect material fo r the Natural History Museum mainly during 1931 but this also remains little worked. The famous explorer W ilfred Thesiger tra\ elled extensi\ ely in the reg ion between 19a6 and 1948 and made many o b se rva tions on the flo ra and fauna, in c lu d in g in \ ertebrates (Thesiger 1959). Indeed, his first cro.ssingof the Rufi al Khali was made possible by a request from O.B. Lean, de.sert locust specialist o f the Foocl and A gricu ltu re O rganisation, that he docum ent locust breeding sites in Arabia. Since the 194Os. most o f the entom ological w ork in the M iddle Fast has been o f an applied nature dealing w ith specific pest problems, in particular mosquitoes and related malaria and locust outbreaks, la ir exam ple. Ta lhouk ( 1969) lists the agricultural ; rests o f the G u lf region.

In the late 1970s. \ arious .scientific expeditions were carried out to some relativ ely unknow n regions o f both the K ingdom o f Saudi Arabia and the Sultanate o f Oman (see B iittike r 1980. Shaw Reader’/r//. 1980. O ullon 1988). These have encouraged further .scientific research and have highlighted the interesting fauna and flora that occur in the Arabian I’eninsula and the lack o f know ledge concerning the liio logy o f the region. They also show the potential for uncovering new records and species as yet unknow n to .science. In [xirticular. Prof. W. B iittike r and Michael Gallagher have endeavoured to ensure not only that valuable biological material is collected and recorded but also that it reaches experts who are a file to study and identify it or describe new species in the scientific literature.

Despite the interest in ne ighbouring countries, ver\ little entom ological w ork has been carried out in the UAE. In consequence, this chapter is not an authoritative account o f the arthropods o f Abu Dhabi but rather an in troduction to their occurrence and abundance, ba.sed on the relatively few records that exist. The Emirates Natural H isto iy G roup have provided some o f the more recent and specific records for UAE. although much of

their material has come from the less repre.sentative habitais, such as w adis and gardens, where the availability o f water and exotic vegetation allows many non-de.sert specialists to become numerous. The true de.serts o f Abu Dhabi have, largely, been ignored. The potential fo r the d iscoveiy o f unrecorded species is high, since not only is there a paucity o f records but also LLA.E lies at the meeting point o f three biogeographical zones, i.e. noithern Palaearctic. African and Asian. The National Av ian Research Center ( NARC) in A fiu Dhabi is collecting and identify ing desert arthropods as part o f its research on the feeding ecology o f the houbara bustard Cblaiiiyciotis iin d u la ia {.see Chapters I, 5 and 6). These records w ill make a valuable contribu tion to the entom ological know ledge o f the Emirate. Records in this review that are not a.scribed to a published source are the first results from the w ork o f NARC.

Review of the arthropods occurring in Abu Dhabi

The phylum Arthropoda denotes a major taxonomic d ivision that consists o f invertebrates characterised by having jointed liml.xs and an exoskeleton. In particular, the SLibphyla Chelicerata and Mandibulata are well represented in desert environs such as Abu Dhabi Emirate (see Barnes 1974 for a fu ll cla.ssification of invertebrates). The form er includes many arid-zone .specialists o f the class Arachnida such as the orders Scorpiones (scorpions), Solifugae (solifugids or camel spiders). Araneae (spiders) and Acarina (mites and ticks). The M andibtila ia includes the classes Insecta (insects), Crustacea (crustaceans) and the m yriapodous or m anylegged Chilopoda (centipedes). By far the most diverse and abundant o f these groups is the in.sects which contains more members than any other single animal group w orldw ide. In contrast, the Crustacea are only repre.sented in the deserts o f Abu Dhal.ii by a single order. Isopoda ( (he isopods ). since the majority o f their members have an aquatic lifestyle

S c ih p h y lu m C h e licc fn taCla.s.-s A r a c h n id aO r d e r .S c o r p io n e s ( s c o r p io n s )

Scorpions have existed on the earth for over 4ÜÜ m illion years and present-day scorpions show- both prim itive and advanced features. This com bination gives them an overall plasticity in response to their environm ent that allows them to survive in the most arduous conditions, in c lud in g desert eco.systems. For exam ple, desert scorpions are able to w ithstand tempeiatures .sex'eral degrees higher than most other de.sert arthropods (see Polis I99(.) for a full description o f .scorpion bio logy).

173

\ I ’ K I . l . I M I I N A K ' i A.S.SL.S.SMhIN I < )l - I I 11. A 1< I I I K( ) l ’ < ) D.S O I' A l U I D H A H I

208

Mosl scorpions prey on other arlliropotls, p ;irlie iil;irly insects and arachnids, but some ha\ e been known to k ill and consume \ eilebia les such as li/ards (see account lo r SfeiKxIciclyliis s lc i'i iii in ( ihaptcrb), snakes and rodents. They k ill by means ot neurotoxins injeeled From their sringinti tails. Some ot the.se toxins are potent enough to k ill a human but most are not deadly, although the sting may be painful for several days.

The seorpions are divided into nine families (Sissom 1990) and four o f these (the buthidae, Chactidae, lOiploeentridae and Seorpionidae) are known to exist in the M iddle East and are therefore like ly to occur in Abu Dhabi, although at present only Buthidae have been recorded.

From the family Buthidae, the genera A i u I i x k I o h i i s ,

Apitboh iitb iis . B irulatus. D iitbaciis, D iitbcoliis. Butbotus, C a iiipso bu tb iis , L c iiin is , L io h iilb iis , M tc ro h iilb tis ,

Ckloiiiobiiibiis. Ortbocbmis. Parahiitb iisAnd I acboiiio liis are known to exist in the Arabian Feninsula. There arc- tw o records o f V 'acbo iiio liisg lob inu iiiiis Levy et al. from Bada Haza in Abu Dhabi (Levy c/rt/. 1973. Vachon 1980). This species has also lieen recorded recently by NAKC from Abu Dhabi Emirate, as have B tilbac iis yoti’ateiisis ii liin x ic iilc a tiis le v y et al. ( Plate 10.1 ). Parahutbasliasoim i ( I lem prich and Ehrenberg), and Coinpsohatbasarabicas Levy- et al. (all specimens verified by |. Boorman in litt.). The genera Anclroctoaas, Bntbacns and Leinrns are considered the most medically im portant .scorpions in Arabia according to Simard and Watt (1990), i.e. tho.se whose venom shows a high toxic ity to humans.

The family Chactidae is repre.sented by the single genus Hnscoipins in the M iddle East, w h ile for the family Diplocentridae, there are records o f tw o genera, Nebo and Heteronebo. In the family Seorpionidae, the three

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209

gcnciLi Hcniiscoipiiis. F a iic liiius and Scoipio ha\ e liecn recorck'tl in die M iddle Hast.

O ix lcr SoliFei^nc ( s o l i f u g id s o i c a m e l sp id e r s )

'I'here are ren know n fan iilies o f these fast m oving and extraonlinary-looking arachnids, three o f which probably occur in Abu Dhabi: the G aleodidae, Solpugidae and Khagodidae (C loudsley-Thom pson 1987). A lthough armed w ith powerfu l jaws that are capable o f penetrating the skin, they do not readily attack humans and, despite much controversy in the past, there is no evidence that they are venom ous (C loudsley-Thom pson 1984). They are predatory, m ainly feeding on o ther invertebrates and, in captivity, their preferred prey consists o f members o f the fam ily O rthoptera (C loudsley-Thom pson 1987)

The fam ilies G aleodidae and Solpugidae are s im ilar in appearance w ith very long legs and sandy colon red, ha iry bodies w h ile the Rhagodidae are sm aller and generally black. Several as yet un id en tifie d species o f Galeodidae ( Plate 10.2 ) and Solpugidae occur in isolated desert areas o f Abu Dhab i and Rhagodidae are often seen around Al Ain where they are attracted to the lights at n ight

O r d e r A r a n e a e ( s p id e r s )

There is very little know n about the spiders occurring in Abu Dhabi, the UAE or Arabia as a whole. Desert species are probably represented by families sim ilar to those- found in the Sahara wh ich are better known. These include ground-hunting spiders (Gnaphosidae), giant crab spiders and crab spiders (Sparassidae andThomisidae

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210

iespeL'ti\ ely ). b;u k spiders ( H ersiliiilue ), juni]Dingspiders (Sukicidiie ), w o li spiders ( Lyeosiikie ), sheet-web spiders ( Agelenidue ), e o iiib ib o ii il spiders (Theridiichie ) und orb- weuvers (Tetragnarhidue and Argiop idae) (Cloudslcy- Thonipson 108 i ). i'w ek e species of Sakicidae have been recorded from Saudi Arabia (Proszynski 1993). They are all predatory and feed m ainly on insects and other in \ ertebrates that they catch liy various means according to the ir b io logy and adaptation. For example, Lycosidae and Sakicidae have excellent sight and actively seek out and hunt the ir prey. On the other hand, web-spinners such as Tetragnathidae, Therid iidae and Argiop idae lay their webs as traps to entangle fly ing insects that the spider can then de\ our ( Plate 10.3). Many desert spiders survive the harsh conditions by staying in burrows during the day and on ly emerge at night. Sonic species can also survive long periods w ithou t feeding when prey is scarce.

O r d e r A cn rin ti ( m i ces :ind t ic k s )

The free-li\ ing mites from arid regions have not been studied nor collected to any extent. However, they probably survive in damp microclimates such as the soil at the base o f plants or on some more specialised habitat such as the bodies of larger insects, e.g. beetles. One interesting obser\ ation from Abu Dhabi is a record o f a giant vek et mite, D in o th ro n ih iiin i sp.. from near the Dubai border fo llow ing a burst water pipe that apparently triggered the emergence o f the mite (Plate 10.4). These are ve iy large mites, about 12 mm in length, and as their name suggests they are covered in a thick layer o f dense, scarlet hair. They spend most o f their lives in the soil in . 1 state of diapause and only emerge fo llow ing hea\y rains when they come to the surface to feed on termites ( CloLKlsley-Thompson 1962).

0 \ \ ing to their blood sucking habit and their potential l( ) transmit rlisease and rerluce the condition o f livestock, ixodid ticks ha\e been studied in the Arabian region though not from Abu Dhabi itself. Hoogstraal elcil. ( 1981) ha\'c re\ iewed the argasid and ixodid ticks o f Saudi .Aiabia and Papadoulos el al. (1991) those occurring in Oman, but neither mentions any records for the UAE. Hoogstraal et al. (1981) also give taxonom ic keys and in form ation on the medical and veterinary importance o f these ticks. They identified 37 species and subspecies, many o f w h ich com m only feed on livestock such as camels, goats and sheep. As we ll as causing blood loss, the ticks may induce anaemia, toxic reactions and paralysis and afso transmit agents pathogenic to humans and domestic stock. The most common tick in desert areas is H ya h m m a (hya lo n in ia ) c lrnn iedarii Kock, the camel hyalom mine, a h igh ly adapted desert species that, as ils name suggests, chiefly infests camels. This species undi lubted ly occurs in the deserts o f Abu Dhabi where ii'' m.iin host is abundant. A few rarer species have also

been identified from Saudi Arabia by Hoogstraal (1982), Hoogstraal et al. (1983a), Hoogstraal et al. (1984) and Pegram et al. (1989).

A few species have also been found infesting marine birds and pigeons (see above references and Hoogstraal and Rafort (1982). Hoogstraal et al. (1983b)). A lthough the ir distributions and range o f hosts are probably w ide, there are no records for UAE. Many lizards caught in Abu Dhabi also bear one or more small red miles or ticks but the identity o f these has not been established.

S u b p h y lu m M a n d ib u la ta C la ss E n to g n a th a O r d e r C o llc m b o la

The Collembola or springtails are m inute, wingless arthropods. They derive the ir com m on name from their ab ility to leap in to the air w h ich they do w ith the aid o f a special springing organ know n as the furca A lthough generally thought to be dependent on high humidityy Collem bola have been found in sandy areas o f Abu Dhabi where they probably feed on the roots o f plants or other decaying matter. To date the ir identity is unknow n.

C la ss I n s e c ta ( tr u e in s e c t s )

Insects are the most numerous members o f the animal kingdom . They exhib it a w ide variety o f form and function, enabling them successfully to exp lo it even the most extreme o f habitats. Desert insects use various mechanisms to con.sen e water and sun ive heat stress and the ir small body size allows them to move into com paratively cooler microclimates during the day. For example, many retreat to deep burrows or the ba.se and roots o f plants where moisture le\ els and hum id ity arc h igher and temperatures low er than in exposed areas. They then emerge at night to feed once the tetiip e rature has dropped. However, there are .some in.sects that are active even during the intense heat o f the day. For example, ants o f the genus Cataglyphis can tolerate temperatures up to 30°C for at least one hour (Delye 1968), Conversely, there are also many insects o f tropical orig in in UAE that inhabit agricultural o r urban areas where they can on ly survive on irrigated plants w h ich are often non-native. This chapter m ainly considers the true d e s e rt-d w e llin g and desert-adap ted species. The classification system used is according to CSIRO (1991 ).

O r d e r T h y sa iiu r a

The Thy .sa n Lira are com m only know n as s ike rfish or bristle tails and are small wingle.ss arthropods usually covered in metallic .scales. They are often found in houses but some species also inhabit the desert, includ ing a few that arc commensal w ith ants. A small num ber o f

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A H K Ü U M I N A K ' i A S S r . S S M E N T O T T H E A R T I I R O P O D S O H A B U D H A B I

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cleserr examples have been found and although their identity is uncertain they are probably from the family Lepismatidae, Irish (1991) revised the Thysanura o f the Arabian Peninsula and found 11 species but had no actual records from UAE.

O rclei' O d o n a to

The o rder O donata includes the suborders Zygoptera (dam selflies) and Anisoptera (dragonflies). Both have a fu lly aquatic larval pe riod and are genera lly associated w ith perm anent freshw ater w h ich , in the Emirates, is la rge ly restricted to some w adis and irriga tio n ditches. There fore they cannot no rm a lly com ple te the ir life cycle in the desert. Dam selflies are sm aller than dragonflies and are least lik e ly to be found away from water, but some o f the dragonflies are m igratory and fly across the open desert. F ifty -tw o species ha \e been recorded fo r the A rabian Peninsula and tw e lve o f these were collected in northern UAE (W aterston and Pitta way 1989). AluixpaiibeiiopeSe\yf=,-^\'\d C rocotbeniiseiythm ea (B ru lle ) have been found in desert areas (W alke r and Pitta way 1987) and are recorded from the UAE in Schneider and K rupp (1993). A s im ila r species that inhabits salt marshes is HeiuianaxeJ)hippi}jerBurme\MeT. This may be more w idespread in Abu Dhabi, but to date has on ly been recorded from Q arnein Island (B row n 1989b). Heath ( 1989) has records o f Selysiothemis n ig ra ( V a nder Linden ), A . partbenopc and Pan ta la J la i 'escens (Fabric ius) from Das Island. Schneider and K rupp ( 1993) also list the fo llo w in g as occurring in the UAE but g ive no specific localities: Iscbn n rn e ra ns i M orton. A rah ic in an isca e rn la W aterston, O rtbutrun i cb iys iig ina (B urm e ister). O rlb o lr iin i sab ina (D ru ry ), Diplacodes le fe b rr ii ( Rambur), Tritbem is a n n n ia ta ( Béarnais), T ritbenusa rte riosa (B urm e ister) and P. flaeescens.

O r d e r Rlattc^dea

Cockroaches generally li\'e in association w ith man and the ir o m n i\o ro u s habit and ab ility to transm it disease th rough con tam ina tion o f foodstuffs means that they can be serious pu b lic health pests. Members o f the genus Heterogamodes are true desert species and can to le rate extrem e arid cond itions (Abusham a 1984) but it i.s uncerta in w hethe r any occur in Abu Dhabi. Urban cockroaches, such nsP erip laneta a m e rican a Linnaeus and BJateiia ge rm a n ica Linnaeus are w idespread, cosm opo litan species (W a lke r and P ittaway 1987).

O r d e r T,sc:>ptera

The Isoptera or termites are soft-bodied, social in.sects that live in colonies made up o f many sterile, wingle.ss soldiers and ^'orkers, and a few reproductive forms. The

latter start life w ith the ab ility lo fly but shed their w ings fo llow ing a mass dispersal phase from w hich just a fev.' sun ive to set up new colonies. Dispersal generally coincides w ith rainy periods and the w inged termites pro \ ide an abundant and rich food source for many animals. Desert species know n from th e ,Sahara construct deep subterranean nests and workers are capable of gathering damp sand from the water table at depths o f up to 40 m (Popov.el al. 1984). T w o foraging strategies are adopted in the desert; species are either nocturnal, or they construct protective soil sheeting or tunnels where they are shielded from the heat and desiccating effects o f the sun. Termites feed on plant material that may be liv ing, dead or decaying. Some species are capable of reducing w ooden structures to dust and may cause serious damage to buildings. Twenty species are thought to occur in the Arabian Peninsula (Chhotani and Bose 1983, 1991 ) but the only record for UAE is o f a colony of Heierolennes ae lb iop ic iis (^o s ie d i) infesting a house in A l A in (B oocock 1979). Judg ing from its know n distribution, Anacantbotennes ochracens (Burm eisier) probably also occurs in UAE although it has not been recorded so far. Se\'eral species o f termites ha\ e been collected in the desert environs o f Abu Dhabi but theii identity' is unknow n (Plate 10.3).

O r d e r M a n to d eu

F am ily M an tidaePorly-.six species o f mantids are known from the Arabian Peninsula, but there are no published records from UAE (Kaltenbach 1984, 1991). However, a desert specialist, the common ground mantis Erem iapbila ba iie ri Krass, has recently been collected from the Baynunah area. Like other members o f this family, it is extremely well- camouflaged and is hard to differentiate from the rocky substrate upon w hich it lives. O ther cryptically-coloured species exist in the desert, liv ing hidden among grass ot shrubs w h ile they lie in wait for the ir prey w hich includes other insects and occasionally small lizards (Plate 10.6).

O r d e r O r th o p te r n

The order Orthoptera includes the grasshoppers (Plate 10.7), locusts, bush-crickets and crickets, and contains some im portant desert specialists. Indeed, tw o species that can cause great econom ic loss to crops, the desert locust Scbislocerca gregaris Forskal and the migratory locust Lociisla m ig ra to ria Linnaeus, have been recorded breeding in the deserts o f Abu Dhabi. Studies o f locusts and related Orthoptera have been carried out by the Anti- Locust Research G roup (now Natural Resources Institute, Chatham, UK) because o f the ir importance as agricultural pests (see Uvarov 1952, 1966 and 1977). They lay their eggs follow 'ing the rains in remote sandy areas. The eggs

1 77

\ I * K I - I . 1 M I N A K > A S S K S S M H N I' O l I I 11 A K T H i t O I ' O I J S O H A M U O I I A M I

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hatch into nigiirless hoppers w hich in certain years may become gregarious and join to form large marching i)ands. The hoppers develop into w inged adults that congregate and migrate in huge swarms. The gregarious phases not on ly behave diffe rently from the ir non- gregarious forms, but also d iffe r in their appearance. Most true desert-dwelling grasshoppers do not fly long distances but prefer to hop using their powerfu l, well- developed hind legs. Many afso have the ab ility to produce .sound using special s tridu la to iy organs or scrapers on the wings.

S u p erfa m ily T e tt ig o n io id e a F am ily T e tt ig o n iid a eTettigonids or bush-eriekets are generally associated w ith vegetation such as herbs, bushes or trees and their occurrence in deserts is therefore lim ited to times or places w ith abundant vegetation. O nly tw o species have f)een recorded in the UAE: Trigouocoiypha a iig iis tn ta Uvaro\' from Sharjah and a m inor pest species Platyciois a lh ifrn tis (Fabricius) at Ras Al Khaimah (Popo\- 198J). There are no know n records for Abu Dhabi,

S u p erfam ily G ry llo id ea F am ily Gry llid aeThese are the true crickets o f which two species commonly occur in Aaabia. Firstly, the house cricket/it7)e/r/ domes!ica Linnaeus w hich is associated w ith human habitation, and secondly, the tropical field cricket G)yIIus bim aeula lus de Greer wdiich is found in vegetateLl areas. A minute, nocturnal species has also been found in desert areas but has not been identified

F am ily G r y llo ta lp id a eMole crickets pos.scss pow erfu l front legs which are fossorial, that is, adapted for digging. They spend much o f the ir life underground w'herc they feed on plant roots and small insects. The adults are w inged and are often attracted to lights. There are tw o species, Gry/lotnlpn gry lln ta lpa Linnaeus and the smaller G aj'ricatia . that are common throughout Arabia and probably occur in L?AE. Gorochov ( 1993) has records o f a third species, GiyJlolalpa dehilis Gersaeker. from Al Madam. L'AE.

S u p erfam ily A cr id o id eaThis superfam ily includes the more numerous and familiar grasshoppers and locusts, some o f w h ich are well- studied pest species. Popo\ (1980) gives 69 species as occurring in Eastern Arabia along w ith a \e iy u.seful taxonom ic key and comments on their biology, ecology and biogeography. There are records for 28 species in the UAE and although most o f these specimens were collected from Shtirjah, Ras Al Khaimah and Khor Fakkan ( in a part o f Sharjah on the east coast), it is like ly that they afso occur in Abu Dhabi

A u.seful w ay o f cla.ssifylng Acridoidea is to split them on the basis o f the habitat and terrain in w liich they arc found. Thus terricoles live on the ground and feed on plants w ithou t actually c lim b ing them (Uvarov 1977) and those w liich live in open deserts can be separated as deseriicoles. In turn, these can be either rr/'e/z/co/ccs', liv ing on sand oy saxicoles. liv ing on rocky substrates. In the deserts o f Abu Dhabi, we w ou ld expect to find mainly te r r i-desert I coles, te rr i-a ren i coles a n d te r r i-.sa.xicoles. Therefore, according to Popov (1980), the fo llow ing species are most like ly to be occur:

Tcrri-dcserticolesA liosc irtiis leagneri (K itta ry ). S ph iiigono tns fe m o ra lis Uvarov. S phiiigonotns octo/ascicitiis (Aud'inet Serville), Sphi ngonot I ispredtetshenskyM\s[ehenko. Sphiiigonotns rnbescens (W a lk e r ) , S p h iiig o n o tn s la e a n d n ln s Popov, P sendospb ingonotnsparadoxus ( B e i-B ienko ), Psendosphingonotns dentatns ( Predtetshensky ).

Terri-arenicolesTeiinitaisnsaiignstnsCQlMnch-MxM.Hyalorrhipiscanescens (Saussure), H ya to rrh ip is a ra b ica Uvarov. Acrotylns insnbricns longipes (Charpentier).

Terri-saxicolesScin iharis ia notablis b lanchard iana (Saussure).

O r d e r P h a sm a to c le a

Fam ily P hasm aticlaeThe phasmids or s lick insects are m edium -sized, phytophagous insects that are very d is tinc tive because o f the ir rem arkable resem blance to sticks or the stems o f plants upon w h ich they li\ e. They are not like ly to be \ ery num erous in the desert ecosystem, be ing confined lo the more vegetated areas. Several s lick-like specimens ha\ e been found liv in g on the desert giwssPennisetnm d ir is n n i ( Gm el ) a lthough the ir id en tity is unkno w n at present

O rd er H e m ip te r a

This order covers the true bugs as w ell as lea llioppe rs , cicadas, aphids and scale insects. True bugs e xh ib it d ive rs ity in both form and lifesty le , bu t they are all chtiracterised by having suck ing m outh parts. Most Hem iptera feed on the sap o f plants bu t some are predatory and feed on anim al tissue or b lood . There are three suborders in the H em iptera : the S lernorrhyncha, the A uchenorrhyncha and the Heteroptera. They arc not pa rticu la rly w e ll adapted fo r desert life and are genera lly on ly num erous w here there is abundant vegetation or, in the case o f p redatory species, o ther insects or prey

7 79

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S u b o r d e r S tcrn o rrh y n ch aThis incliiclcs m o him ilies rhnt o in hccomc serions pests o f crops. They ure the families Aphiclidae and Coccoidae, know n as aphids or plant lice and mealy-bugs or .scale insects respectively. Both tend to Ise veiy small and li\ e by sucking plant sap. In many species, females can reproduce w ithout mating ( pathenogenesis) a llow ing populations to bu ild up \ ery rapidly. As well as causing damage to the plant by rem oving sap, they can also transm it plant \iruses. Sixty species of coccidids are kno w n from Saudi Arabia (M atile -l’errero 19<Si, 19BS). These ha\ e the potential to cause serious economic damage because o f aridity o f the countiy (Matile-Ferrero 1984 ). A lthough they undoubtedly occur in both cultivated areas and the deserts o f Abu Dhabi, there are no records to confirm this.

S u b o r d e r A u c h e n o r r y n c h a F am ily C ica d id a eCicadas ha\ e a \ ery long-1 i\ ed nymphal stage that learls a subterranean existence and is seldom seen. Adults are com parati\ ely short-1 i\ ed and spend their rime on trees. The males are conspicuous because they can produce a \ ery loud noise w ith w hich they attract females. They do this by means o f a paii o f special organs, the tymbals. w h ich arc situated on the afidomcn. The Arabian cicaila PU ilyp/c iirn (in ih ica Myers i.s common among stund.s ot trees in L'AH.

S u b o rd er H e te ro p te ra S u p er fa m ily P e n ta to m o id e aIn Arabia the most frequently oeeuiring families are the D in idoridae anil the Pentatomidae both o f w hich feeil on p lant sap. The D inidoridae includes the melon bug C orid i/is f if l iK if i is Fabricusa. a large black bug that feeds on native Cucurbitac but which may becotne a pest il numbers inerease anil it in\ ailes cu lti\ ateil erops. The Pentatomidae are com m only known as shielil bugs because o f their shape, or stink bugs because o f theii ab ility to exude ;t foul-sm elling flu iil when handleil. L innaxuori (1986) lists 4s2 species ol Heteroptera as occurring iti Saudi .Arabia, many o f w hich are new taxa. It is like ly that Abu Dhabi shares many o f these species an il they w o u lil be expecteil to lie w iilespreail w here\ er the ir plant hosts occur.

O r d e r N eu rop L era

In the desert ecosystem tw o families of N euioptera com m only occur: the Chrysopiilae or lacewing.s and the M yrm eleontidae or ant-lions. Both ha\ e predatory lar\ ae, the C hrysop iilae specia lis ing on aphids an il the M yrm eleontidae on ants, but o f the adults on ly the Chrysopiilae are predatory. The M yrm eleontitlae are by lar the most numerous and include many species whose

laiAae are adapted to desert conditions. They gel i Ik ii comtnon natne o f ant-lion from the Ian ae w hich kx d ferociously on ants. Most species con.strucl conical p itlike traps in the sa ml and flick sand grains ;it any passing ant. Ants that fall into the trap are im m ediate ly attacked anil de\ oured by the lari ae using the ir sharp, sickleshaped mouth-]iarts. A few ha\ e free-li\ ing larvae that do not produce traps but actively seek the ir prey instead. Adults superfic ially re.semble dragonflies but can be ilifferentiated by their clubbed antennae and net-\ eined wings, llo lz e l (1982, 1983 and 1988) lists 136 species know n to occur in the Arabian l^eninsula but there are no published records o f the species that occur in UAE.

O fc le f C o le o p c e i a

More than 300.000 species o f Coleoptera or beetles ha\ e been describeil w o rlil w iile an il about 40 "n of all insects and 30" I, o f a II animal species are beetles. Not surprisingly, they are one o f the largest groups in the de.sert and pi(>bably make up the largest biomass o f in \ertelirates that occur there ow ing both to the size anil abutidatice o f some ilesert spei ies. The Coleoptera m entioned here :ire those that are most numerous in .3bu Dhabi and w h ii h show .some ilegiee ol ilesert ailaptLilion

S u b o rd er A d cp h a g a Famil>’ C arab ldaeOne o f the most fam iliar ilesert beetles is A iith ia cliioc/cciiuii’ iiltcilci Bonelli. com m only know n as the ilom ino beetle (Plate 10.8). Like other t. arabiils it is an acti \ e predator and is often seen scurrying around the ilesert both by ilay and night. It prei son other in\ ertebrates but w ill also seax enge on earcasses o f \ ertebrates. Another common carabiil i.s .S'(.Y//V//e,s spp. ;m aggre.ssix e nocturnal pre ila tor w ith \ cry large, pow erful mouthparts.I he l.i biinae and Brachininae carabids o f Arabia ha\ e been re\ iew eil by Mateu ( 198()) but there are no records for Abu Dhabi or the UAE.

Fam ily C ic in d c llid a cTiger beetles are fast-mo\ ing, actixe preilators xx ith large sickle-shapeil jaxx s xx hich feeil on small inx ertebrates. There is a species o f tiger beetle that often frequents the seashore, muilllat.s anil sabkha in Abu Dhabi anil this is \m )\yA\')\y liiin ihi/iir-dbÙLUs. tilthough its iilentityhas not been confirmed. Txxo species o f tiger fseetle, p iobably Cicindclci ii in iu ii i is (Bates) an il C. I it in ila la . haxe recently been fourni on Meraxxah IsLinil.

S u b o rd er P o ly p h a g a F am ily H is ter id a cH iste rills are genera lly sn ia ll shiny, b lack, tough and very rounded beetles that are found on carrion o r dung. It is though t that they are actually p redatory an il lix e o ff

/ , S ( I

A MUHLIMIN Xs.sLSMMliNI' Oh I H I: ARTHROPODS OK A B l' D IIA B I

"21^

the laiATie o f 11 y and o ther beetle species that inhabit these places. Several d iffe re n t species o f histerids ha\ e been found in Abu Dhabi but the ir iden tity and b io logy are unknow n .

F am ily S carab aeid aeThe fam ily o f scarab beetles includes the dung beetles and chafers both o f w h ich can be quite numerous.

The most cotnm only occurring dung beetle in UAE is Scarabaeus crislatus Fabricius. It may frequently be seen fly ing over the desert and is often attracted to lights at night. It fo llow s herds o f camels and other livestock and can be seen ro lling balls o f precious dung across the sand searching for a suitable place to b u iy them. Having buried the dung the beetle lays a single egg and seals the entrance to the tunnel. The lanTt then hatches into a secure environm ent w ith the dung acting as a food store fo r its development. It is not on ly dung that is u.scd, however, and dung beetles may dissect and ro ll-o ff dead animals such as gerbils (Plate 10.9k This behaviour is also know n from some African species o'f Scarabaeus ( Scholtz and H o lm 1985). G ille ll ( 1994) has collected 32 species o f Scaraliaeidae m ainly from the Al A in area. Table 10.1 lists all the species o f dung beetles he has identified.

Chafers arc plant-feeders and their Ian ae generally Ih'e on roots o f plants and in .some cases can cause economic dtimage to crops and ornamental plants. Many adult beetles are attracted to artificial light at night. Several species have been collected in Abu Dhabi but their identity is unknown. G illett (1994) has records for 14 chafers found in the Al A in region.

F am ily B u p restic laeBuprestid or jewel beetle lan'ae feed under the bark of trees w h ile the large, m etallic-coloured and bullet-shaped adults are free flying, feeding on pollen and flowers. They are generally restricted to plantations or forested

areas but w ill also sun ive on i.solated Prusopis and Acacia trees. Several have been collected at Al A in and Um Az Zim ul but their exact identity is unknow n. Their elytra form a conspicuous com ponent o f little ow l (Athene noctua) pellets found near the Abu D hab i/ Dubai border.

F am ily E laterid aeElaterids or click beetles have larvae that feed on the roots o f plants. They get their com m on name from the ab ility o f adults to turn themselves over by Hexing their body and producing a c lick ing noise in the process. The body shape o f the adults is typ ica lly elongated and flattened Chassa in (1983) has records fo r 12 species o f Elateridae from Arabia and. although none are specifically from UAE, this beetle fam ily certainly occurs in Abu Dhabi as they are often attracted to artificia l light at night.

F am ily D e r m c st id a eDermestids are com m only know n as carpet or hide beetles and are scavengers, feeding on carrion and animal carcasses. In the desert they and other carrion feeders are responsible for the .swift remox al o f dead animals. There is currently nothing know n about those that occur in Abu Dhabi

F am ily C o c c in c llid a eMost cocc ine llids feed on aphids but a few are phytophagous. The commonest ladybird in Arabia is the seven-spot ladybird Coccine/lasepfenipiincfata Linnaeus, a prechitory species that may be found on desert plants in Abu Dhabi

F am ily T e n e b r io n id a eIn terms o f desert survixal, tenebrionids or darkling beetles are the most numerous and succe.ssful coleopteran family. They are highly adapted to water con.seiAxition

Tabic 10.1. .Spccic.s o f .ScLirabaciclac iV o m I he HA f

c o llc c tc U h\ (.'lilk-ll (190-1)

Âlilill pl\ 1 -( ■

LûljU y i jA Scanihiicidae .G illett 0 9 9 4 ) US

Species n a m e

S c a ra b a e u s c ris ta l us F ahric lo .s

G v n iiio p le u ru s s p l

G y n iiio p /e u ru s s p 2

C a tb a rs iu s iu eru U s (C a -s tc in n o )

C h iro n it is osiricUs R c ic h e

O u th o p b a g u s n itic iu lu s King

O u th o p h a g u s u a rie g a liis C Fahnc iu .s )

O n th o p h a g iis tra n s c a p ic u s ( K o e n ig )

O n tic e /h is .sp]

O n U ce llu s ,sp2

ApbocUus s p l

AphocUus .sp2

Aphuctius .sp3

A p b o d iu s .sp i

A p haciins s p 5

L o c a lity

A l A in , A l A in A l F a y c la h , A l A i n - D i i h a i r o a d , A l O ita .

M a h t la h a n d F(.>ssil \ a lle y

M a h d a h a n d A l A in A l F a y d a h

M a h d a h

A l A in —D i ib a i r o a d , A l A in —A b u D h a b i lo a d ,

A l A in —A l W ig a n r o a d a n d A d h D h a id

M a h d t ih a n d A l A in —A l W ig a n ro a d

Al A in —A l W ig a n ro a d . A t A in A l F a y d a h , M a h d a h

a n d Fo.ssil v a l le y

A l A in —A l W ig a n r o a d a n d M a h d a h

A l A in —i3 u b a i ro a d a n d M a h d a h

M a h d a h

A l A in

A l A in —A l W ig a n ro a d a n d M a h d a h

A l A in —D u b a i r o a d a n d M a h d a h

A l A in . A l A in —A l W ig a n ro a d , M a h d a h a n d Fossil v a l le y

A l O h a a n d A l A in —A l W ig a n r o a d

A l A in —D u b a i r o a d a n d M a h d a h

181

A l > K l £ L l M I N A i n A S . S K S . S M h N I O T T l l l v A U T H R O P O D S O F A l U I D l l A U I

ZTB

P la tt: 1 0 .8 . T h e d o m in o b e e t le . \ i i l h i t i r l i io c le c in in n lU lU l b o n e l l i is a n a e t i\ e p r e t la lo ty e a ia b id . o f te n s e e n a ro u n ti s u n se t.

A tith ia c liu x lec ln if’ i i l ta la Uonclli «L-iüJ a - \ . i» . jl J Carabidae iU J l ^

P la te lO .y , O u n j i b e e t le s .V<.Y/;v'/b/'«'/f.s' c r fs l i i / i is F a b iie iu s w i l l i l r a x a n t i ro ll e are as s es l ik e th is t ie a t l > -e ib il iC Jerh iH ns t7 > e e .v /; /< /; / /T h o m a s ) s e e e ra l m e tre s b e fo r e te a rin i> ih e n i a p a r t a n t i b u r y in j; th e m in p ie c e s

Scamlxicn.s chsUiltis Fabricius i j j H ^Thomas) làt J l. .lùdl j aw f Â

r Â J ! W*j>“ Jfi (CerhiUns chcvsmaui■ U».V 1+Ü1J

P la te 10. I t ) . I ‘r it> in > lh cc ti c iin n u i lc i ( O l i \ ie r ) is th e la rg e s t o f th e de.sert te n e b r io n id s in U A F .

jjSI Piionotbeca cnronata (O liv ier) i . - 1 .> 7 ' tfi Tenebrionidae Âüdl W l l j jL iiJ

/.S’J

A I ’ K K I . I M I N A K ' » A S S R S S M I N r ( } | I I I I : A K I 11 K l ) I ' i ) I )S ( ) | \ I U I D H A H I

2tr

Plate I 0.1 I. M c s i i s l i ’i u i iH i i u l i C d l I i s Soller is pn ihahly ihe nu isi numerous Il nr I «I il m ill in Ahii |)liahi.

^ M esosteiia fw iiL lic n tlis S o h e r M - l . ê.^1 ■ lï^ j^ ' l-ut T fn i'h r io n id a e é tU il i» jlill

Plate 10.12. / ' i i i i f / i i i < i i t i h i c i i Kluj; i.s

anoiliei eommon ile.se-ri lenehrioniil

> j t-»* J* arabica KIuh i'f-> • i^ jlTenebhnnidue s ü J l >— J ,>L üJi

A I ’ K U L I M I N \ R > - A S S U S S M H N T ( ) H T H T . A R I H H O R O D S C.5F A H l ' D l l A B I

218

L in d can obtLiin all the water they need through their own metabolic processes. Most are scavengers or plant feeders. They are generally black or dark colou ied and show d i\ ersity in size ranging from the m inute to the ve iy large. The largest species found in UAE IsP rionotboa i coro)iata (O liv ie r), com m only know n as the urchin beetle, w hich is about 40 mm from the head to the tip o f the abdomen (Plate 10.10). Many o f the larger tenebrionids have their elytra fused and although they have lost the ir ab ility to fly they are thought to have an increased ab ility to retain water. A lthough large and obvious, many are avoided by vertebrate predators because they are distasteful. Most are crepuscular or nocturnal in habit.

Kaszab (.1981, 1982) lists over 300 species o f tenebrionids as occurring in the Arabian Peninsula, but veiy few examples have actually been collected from UAE and even few e r from Abu D hab i Em irate. Tenebrionids are an abundant and im portant com ponent o f the desert ecosystem and many species exist in Abu Dhabi. Table 10.2 lists the species presently know n to occur in UAE but it is like ly that many more w ill l)e found in the future. Typical examples include Alesostena p iin c lic o llis Sol ier (Plate 10.11) and the hvgev P in ie lia arab ica K ing (Plate 10.12). Sand swimmers, w hich are members o f the genus Froclius are also abundant in some desert areas.

Fam ily M elo ic laeA du lt Meloiclae or o il beetles are often very co lou rfu l and may be seen feeding on flow ers o f various plants. T h e ir close association w ith f low e rin g plants means that they are generally on ly seen in desert areas fo llo w in g the rains, but some species can cause serious econom ic damage to crops. Many have an aposematic o r w a rn in g co lo ra tion to advise predators that they are distasteful o r even toxic w hen eaten. Lan ae are thought

to be parasites or parasito ids o f o ther a rth ropods but there is litt le kno w n about the ir b io lo gy in Arabia. E igh ty-e igh t species have been listed fo r the Arabian Peninsula (Kaszab 1983, Schneider 1991) bu t records fo r IIA E and Abu D habi are scarce, a lthough this p ro ba b ly reflects a lack o f know ledge rather than the occurrence o f desert species. G ille tt ( 1992 ) htTs found a potentia l pesi species E p ica iita erytbrncepba la (Pallas) feeding on w ild plants in Oman, fa irly close to the Al Ain area o f Abu Dhabi.

F am ily C er a m b y c id a eThese are large longhorn ' beetles whose larval stages live and feed under the bark o f trees such as acacias. One species A cantbopboriis a rab icas (Thom son) has been found at Svvcihan in Abu Dhabi Emirate. Holzschuh (1993) lists 54 species or subspecies o f cerambycids occurring in Arabia but has no records for the UAE.

Fam ily C u r cu lio n id a cThe CurcLilionidae are com m only know n as w eevils. They are all phytophagous and their lanae usually li\e and feed in a protected en\ ironm eni such as the root oi shoot o f a plant, wh ile adults feed on the external parts o f plants. Adult w ee \ils are easy to distinguish from olher Coleoptei'a because they have prom inent snouts or rostrums and elbowed or angled antennae. They are not w ry common in the de.sert but a few smaller species such as Anuin)cleo)ias ascbahaiicnsis Faust have been found on ZyiidpbyHiim spp. plants in Abu Dhabi.

O r d e r D ip te r a

W orldw ide this is one o f the largest orders o f in.sects. although in the deserts o f Abu Dhabi there are many individuals from just a lim ited number o f species. The\

Species n a m e ,

Znpbosis n i ig e a n x i s im p le x K a .s zn li (1 9 S 1 )

P a c h y c e ra p y g m a e a a m b ic a (C K o c l i )A ie s o s lf iu ip n iic r ic o l/is S o lie r

M ic m d e ra in c iig iiin ta d es e itic o la (B la i r )T e n ty n n a d e s e n a sp a isep u iic ta tc i K a.s /.a lj ( 1 9 8 t )

O xy c c im h u e tt ife r i K a s z a ti ( 1 9 8 1 )A desm ic i c o rh iirn a /o o n ia n e n s is K a.sza lr (1 9 8 1 .)

A d e s m ia c n tb n rn a ta ra th je n s i S c lii is te r

Adesm ict s io e c k le ir ii ra s a lk h a m n t ia K n s z a li ( 1 9 8 1 )

P a ra p la ly o p e a ra b ic a a r a b ic a (B ta ir )

T ra c h y d e rn ta h is p id a (F o rs l< )T rn c b y d e rm a p b ih s t in a R e ic l ie a n d Sa n ic y

T b r ip ira b r a a iz i H a a g -R .P im e U a a r a b ic a o m a n ic a K a s z a b (1 9 8 2 )P irn e iia a r a b ic a a ra b ic a Kln^P irn e tia a r a b ic a e m ir i K a s z a b (1 9 8 2 )

C o n o c e p b a in m b e s n a rd i K a s z a b ( 1 9 8 2 )

O p a ira id e s pu n c ia la tiL S B r u lte

O p a tro id e s v ic in n s (F a ir m a r ie )P b a le r ia p ro H x a F a im ia r ie

L o c a lity

Ra.s A l IC Iia iin a li Ra.s A t K l ia lm a l i . D ilil^ a

Ras A l K h a im a h , D u b a i D i l ib aRas A t K l ia im a l i , lOitrlna

Ra.s A l K h a im a h

Ras A l K l ia im a t i D ib b a

R as A l K l ia im a h

Ras A l K h a im a h A b u D l ia b i

Ras A t K l ia im a h . D u b a iM a sat'iDulxiiD u t? a iRas A l K l ia lm a l i

R as A l K l ia im a h Ras A l K h a im a h

R as A l K h a im a h

“T r u c ia l O m a n "

Tabic 10.2. I.isi 11| tcncbi ii m ill bc fllcs kiK iwn tn im OAK.

Alter Kaszab t 1081 1V82)

Hjldl sajUJI is il ^1^1 CÛÜ T —t < d jd* Tenebrionidae

.Kaszab (1981, 1982) j c .s.w iall

is /

A PRm.I.MI \ \K 'i ASSrsSMTNT OT TIIP: ARTHROPODS O P A B l^ P ^ lA B l

CLin be cliscingLiishecl from other flighted insects liy tiie ii single p iiir o l wings. The second pair is reckiced to a small club-shaped structure know n as a haltere, which is im portant for balance and stabilirs' during flight. The hcause fly M iisca clonieslic{i Linnaeus is ub iquitous and capable o f spreading di.sea.se as well as being a general nuisance and irritation. In the M iddle East, some w ork has laeen done on those flies that are a potential hazard to the health o f humans and the ir livestock, but little interest has been shown in those families that contain m ainly non-pest species.

The D iptera are split in to tw'o suborders, Nematocera and Brachycera, on the basis o f their m orphology. The B rachycera are fu rth e r sp lit in to tw o d iv is io ns , O rthorrhapha and Cyclorrhapha.

S u b o rd er N e m a to c e r a F am ily C u lic id a eA num fier o f species o f mosquito has been recorded from the Arabian Peninsula, and studies o f these insects have concentrated on their im portance as medical or \ eterinaiy pests since some species are capable o f transmitting diseases. One such disea.se i.s malaria, although in recent years there have been few cases reported from the Arabian Peninsula.

Fam ily C e r a to p o g o n id a cBoorm an (19S9) has w ritte n an account o f the genus CuHcoides or b iting midges o f Arabia and lists 2-f species a long w ith notes on th e ir b io lo g y , d is tr ibu tion and ab ility to transm it disease. Five species were found in UAE: Cti/icoicles irc ird i Boorman. C. rcii'iis de M e illon . C. o.xystonia K ieffer. C. in nco la K ie ffe r and C. cizerbcijdzhciiucits'Dzhw'i-Moy. Apart from C. oxystonia and C. inucoki. there is little know n about the pest status o f these species. C oxystonia is kno w n to be a serious

b itin g pest o f cattle and it may also be able to transm it cattle filariae. C. inuco la is a very serious veterinary pest and is a kn o w n vecto r o f A frican horse sickness, b lue tonguc v irus and A kabanc virus.

C. inesgbalii Navii has recently been added to the list for UAE, identified from the Baynunah area (J. Boorman in litt.). Noth ing is know n about disease transmi.ssion in this species w h ich was caught b iting the author!

F am ily C h ir o n o m id a eFifty-three species o f Chironom idae or non-b iting midges have been recorded fo r the Arabian Peninsula (Cranston and Judd 1989). C hirononnis cciliptenis is the only species collected from Abu Dhabi where it was reported to be a nuisance pest around the A l Ain sewTige works, occurring in veiy large numbers.

S u b o rd er B ra ch y cera D iv is io n O ith o r r h a p h a F am ily T a b a n id a eThe ta ban ids are com m only know n as horse-flies or clegs. Males are harmless but females require a blood meal for the developm ent o f their eggs and some species are pests o f livestock and an irrita tion to humans Tabanids probably occur in Abu Dhabi but have not been recorded.

F am ily A silid a eThe asilids are know n as robber flies, and are active predators that capture other insects on the w ing. Members o f the genus Apodea are com m on in desert areas o f Abu Dhabi.

F am ily B o m b y liid a eThese are com m only know n as bee flies because o f their superficial resemblance to bum ble bees and the ir sim ilar

Tahle I (I..S. UcinhyliiiliUs hLC lliu.s iVoiii I'

.M 't f l- C ' . I f ; i t h f ; K l I UI.S.Si

ji Bdnibyliidaf CUr. j-ijii r - \ .

•Circarhcatl (19HK) j .

Species n a m e L o c a lity

B a n ib y liiis iiieÿciccpheiliis Poivllin.skii Harm—At Madam RuadA iu is lo e c h iis niL’cus Hermann HarmSystoccbns h o rr it ln s Greathead HartaB<ii>ibylisrima SPiiegn/ense ( Macc|ii:irO Harra, .Sweihan roadPcirorossei tropiccilis liJezzi HartaPclixtirissci (tlb ifd c ies (MaccjLJart) LIAJZD e sD ia lo iie iirc i b rec ip en n is (.Bezzi) Sliweila—At Madam RoadDesinciU nieiirei .sp. Sweihan ruadA n th r a x in fd sc la tc i Meigen Wadi Al Fay, near DibbaSpogostylnni cdn clic liin i I Sack I As Sa adSpogostyluni tnippoytd (Wiedemann) ■Shweib roadSp ugvslylnni ucyd le (Wiedemann) Hartan y r ic ld ) i lb r d x c lec ip iild (Ansren) Shwcil-»—Al Madam Road7 b 1 Tictd n th r a x p e r i c i Id n's p e r ic ila ris (Loew) Wadi Al Fay. near DibbaFxt.tyata m b r a x b ec h erian n s (BezzO Wadi Al Fay, near DibtiaP d c h y n tt ih ra x n n n u u td n n (Greathead) Shweils—Al Madam RoadV e rib n ijd d iig d s te o c n ld liis (Becker) Ras Al CharV erib n b o a im s ( Wiedemann^ Al Bahrani I.siandH e te ro to n id itieg er/c i (Meigen ) FlartaH e le ro /a n id n n ic n re a (King) As SaadJ ie te ro h m ia o tiv ie r i (MacquarO As Saad

A l ’ R l i L I M I N A K ' ï A S S F S S M h N f O F T H F A R T H U O P O H S O F A H H D H A B I

“ 220

liab it o f feeding on nectar-pmciueing Howers. They are im portan t as po llina to rs and several species occur in Abu D hab i. G reathead ( 198<S) lists the records in Table 10.3 fo r UAE.

D iv is io n C y clo rrh a p h a F am ily C a llip h o r id a eThese are the fam ilia r b luebottles and greenbottles w hose la rvae feed on ca rrion and o th e r dead organ ic matter. Some, such as the w in te r greenbottle L u c ilia seh ca la M eigen, w ill also lay the ir eggs on the w ounds o f livestock, causing them considerable pa in and d iscom fo rt as w e ll as preven ting norm al healing . N ot recorded from Abu D habi a lthough they p ro ba b ly occur.

F am ily M u sc id a ePont ( 1991 ) lists 68 species o f the fam ily Muscidae from the A rab ian Peninsula but o n ly fou r o f these have been recorded from UAE. Many such flies are po tentia l p u b lic health pests because o f the ir ab ility to transm it disease by the con tam ination o f foodstuffs. The most im portan t o f these is M iiscci c/oiiieslicci cloiueslica Linnaeus, the com m on house fly, w h ich can be found even in isolated desert areas. S im ilarly, the subspecies M usca doniesUca ca lle ra W alker has also been recorded fo r L^AE as have M u s c y i l i ic id i ik i Loew and AIiiscci .so / 7;e/ / s W i e d e r m a n n .

O r d e r L e p id o p te r a

M oths and bu tte rflies tend to be the best-studied insects because o f the spectacular beauty o f some m em bers o f th is o rder. They h a \e a com p le te m etam orphosis and the ir larvae spend most o f the time eating to b u ild -u p the food resources required to

ach ieve th is tra n s fo rm a tio n . The m a jo rity have phytophagous larvae that feed on one o r a few specific food plants l.iut some larvae are insectivorous. In general, the adults have a co iled proboscis w ith w h ich they feed on the nectar 6 f plants or o ther flu ids , bu t some have a troph ied m ou th parts and are incapable o f feeding. They spend most o f the ir life as a ca te rp illa r and on ly em erge a.s adults fo r a very short tim e to mate and die. Some species m igrate as adults and may occur in rem ote reg ions a long way from w here the ir larval food plants are found.

Larsen (1983) has wndtten a c o m p re h e n s ive m onograph o f the 151 species o f bu tte rfly ( Rhopalocera ) wdiich occur in the Arabian Peninsula. W iltsh ire ( 1983, 1986, 1988 and 1990) has rev iew ed the d is tr ib u tio n and abundance o f the 625 species o f M acro Heterocera (la rger m oths) w h ich are found in Arabia, Those that have been recorded in LIAE o r are though t to occur there are listed be low w ith comments.

S u p erfu m ily C o sso id e a F am ily C o ss id a eThe cossids are com m on ly kno w n as goat and leopard moths. / lo lce rce riis j^ lurios iis Erscho\- is com m on in grassy sand dunes and ho llo w s in eastern Arabia (W alker and Pitta way 1987). It has not been recorded in UAH although it p robab ly occurs there.

S u p crfa m ily I^ ra lo id e a F am ily P yralidaeThere are no actual records o f pyra lid moths for UAE a lthough they undoub ted ly occur there and it is su rp ris ing that e\ en the M editerranean Hour moth EphcsHa kticd in ie lln Zeller, a serious pest o f stored products, has not been recorded. O ther non-no.\ious species such dsLaiuorici ciiiollci Denis and Schifferm üller

Species: n a m e

G o in a lia e h n a e ln ia Trimfn

S p ia lia d o n s d n ris Wiiltcer

S p ia lia cololes se triico n jliie iis De Jong

S p ia lia z e b ra b if id a Higgin.s

P e lo p id a s m a lb ia s m a th ia s (Fabricus)

G e g e n e s p n n U lio ssp

C o m m o n n a m e

African mallow .slvipper

Deserc grizzled skipper

Grizzled skipper

Zebra grizzled skipper

Lesser millet skipper

Pygmy skipper

L o ca lity

UAF. (lîrown 1992)

UAE (brown 1992)

UAE (Brown 1992)

UAE (Brown 1992)

Khor Fakkan (Larsen 1983), UAE (Brown 1992)

UAE (Brown 1992)

Table Id.-I. The skippei btit lerll ies c >1 I A F

al>^1 J i ilkill jiljill t- H Jja» .1.13,0*11 4 *11

Sp ecies ':riam e. . - .: ' f C o m m o n ■name: .

P a p il io d em o leu s d en to le iis Linne Citrus swallowtail

P a p it io m a c h a o n m u e lin g i Seyer Swallowtail

'.Locality

Felij, Al Ain and Sharjah Clairsen 1983),UAE fBrown 1992),Al Ain Zoo (Wingate 1992), Das Island (Reaney 1987)

UAE (Drown 1992),Al Ain Zoo (Wingate 1992)

Table lO.S. The s\\ allow tail

biittertlles o f I I.AE.

CjIjUyi >. 11,1.11 jü jill Ô-1 .

!S ( )

A P R F . IJ .M IN A i n A S .sE .S S .M F N ’l O F T H F A R T H R O P O D S O F A H LI D H A H I _ 221-----

T a b le K I 6 T in - pii. r id In iltr i Ilie> ol I 'AH

^ Pifriclae ^U l j li ji ll . Jja»

; Comwiore,:K«me.“De Niccvillc Small while

P o n tia i ila n c o n a n ie (.K\up.) Desert white

E u ch lo e b e le tn ia belem ici CEsperl Green striped white

E lp h in s to n ia c h a r lo n ia a m s e li Desen black tip(Gross and Ebert)

A n a p b a e is a i im ta (Fabricius) Caper white

Cn/otis c a la is a m a m s Fabricius Small salmon Arab

ColoHs p h is a d ia p h is a d ia (Godurt) Blue spotted Arab

Colotis H agore Klug

M a d a is fa iis ta fa u s ta (Olivier)

C a to p s ilia J lo re lla (Fabricius)

Desert orange tip

Salmon Arab

African emigrant

A p harU isacc irnash ypaigym s(\iux\t::\) Leopard butterfly

E u re m a h ccah c senegaleusis Grass yellow

i j^ i Çjjdi CjijUyi A rto g c ia ra p a e Linnaeus Small cabbage while

UAE (Brown 1992)

Al Ain Zoo, Fujairah (Larsen 1983),UAE (Brown 1992),Das Island (Reaney 1987), Merawah Island (Brown 1990)

Sharjah (Larsen 1983)

Wadi Shaab (Larsen 1983), UAE (Brown 1992)

Felij, Jebel Flafit, Dubai (Larsen 1983),UAE (Brown 1992),Das Island (Reaney 1987)

UAE (Brown 1992),Das Island (Reaney 1987)

Sharjah, Al Ain (Larsen 1983), UAE (Brown 1992)

UAE (Brown 1992)

Al Ain (Larsen 1983),UAE (Brown 1992)

Khor Fakkan, UAE (Brown 1992),Das Lsland (Reaney 1987)

Al Ain (Ltirsen 1983)

UAE (Brown 1992)

Das Island (Reaney 1987)

did likd l) to b t‘ tound in odses and s tone-s lie \\ n plain.s (W a lke r and Pittaway I )

S L ip c r la n iil> H e s p e io i t lc a F a m ily H c s p c riic la c -rhese aid co inn ion ly know n as sk ippd i h iittd illids and can hd d is tinguished from other b iitte rn ies liy the way they lay the ir hind w ings flat lin t keep the ir forew ings in a vertica l pos ition w hen at rest. Table KJ.t lists the species recorded as occu rring in UAE.

S u p e r fa m i ly P a p ilio n o ic le a F a m ily P a p ilio n ic la eThese are the fam ilia r sw allow tail bu tte rflies that ha\ e a gracelu l flig h t and generally possess a p ro jection or ta il' on the back edge o f the ir h ind w ings. Table lO.S

gives the species recorded in l^AE

F a m ily P ie r ic la eThe p ierids are com m only know n as w h ite or su lphur bu tte rflies since most are p redom inan tly w h ite , cream o r y e llo w in co lour, a lthough a few species are light p ink o r orange. The most com m on lar\ al food plants o f the pierids are members o f the Brassica fam ily, includ ing crops such as cabbages and radishes. Sometimes the laiATie can occur in sufficient numbers to cause economic damage. Many species are strong m igrants and occur w ide ly across the whole Arabian Peninsula. For example,

m igrant species such Aiu ipbcie is ctnraUi (Fabric ius) M dcldis/c iiis lc i fd iis id (O li\ ie r) a iirl C citops ilid J lo iv lla (Fabric ius) ha \e an unpred ic tab le annual d is tribu tion and abundance. H o w e \e r, some pierids have on ly a lim ited d is tribu tion such as F Jph iiis lo iiia cbctrlon ia (in ise li (Gross and Ebert) w hose larvae feed on locally occu rring w ild cruc ife rous plants. The species know n from the UAF are listed in Fable 1 ().().

F a m ily Ly c a c n ic la cMost lycaenids are predom inantly blue in colour, hence the com m on name o f blue butte rflies In some species there is a m arked sexual d im orph ism w ith showy, blue males and brow n, c ryp tica lly co loured females. Mans s])ecies are m igrants w ith a w idespread occurrence, such :\s Ldiiipicles hoeticiis ( Linnaeus) w hich uses a w ide range o f larval food plants. Others are con fined to areas where the ir lar\ al food plants occur. For example. T c in ia is loscicens ( Austraut) and more rare ly T ariic iis bcilkcin iciis (Freyer) are found where Z izypb iis sp grows. A lthough Zizeeha karsancbri karscuuira (Moore) is a weak flie r, it is qu ite wdciespread p robab ly because cu ltivated alfalfa is its most im portan t larval food plant in Arabia. As a whole , the fam ily has a w ide \'ariety o f larval food plants in c lud in g tree species such as Prosopis and A cac ia w h ich are used by Cbilades p a rrb a s iiis (Fabric ius) Table 10 7 gives the species know n from the UAH.

7,S':

A I ’ R l i L I M I N A K ^ A S S F S S M |-:N 1 O l ' T H l i A K T I I R O PC) O S <.)1- A B I j D I I A B I

^ 22-

F am ily N ym p h a lic laeThe n y n ip h iilid h im ily incliiile .s tlie to rto iseshe ll, m ilkw eed , b ro w n und fr il i lh iry bu tte rfiies w h ich make up a c o lo u rfu l and \ aried ^ ro u p 'I'hey are ve iy capable llie rs , but the ir fron t legs are small and they w a lk using on ly the ir m idd le and h ind legs. D a n a iis chrys ipp iis cbrys ipp iis (L innaeus) is abundant and has a very- w idespread d is tr ib u tio n th roughou t Arabia.

Vanessa ca rd u i ca rc iiii (Linnaeus) is a true migrant and it is veiy com m on at times across the wdiole Arabian Peninsula. Hypolinn ias misippus (Linnaeus) is also a

m igrant but shows considerable fluctuation in numbers, w h ile 1 p th in u i bo lanica Marshall is thought to be confined to the more m ountainous regions. Its laiA'ae probably feed on grass as do those o i'H ippa rcb iapa risa tis (K o \h r). Table 10.8 lists the species recorded in UAE.

Sui:>erfamily G e o m e tr o id e a F am ily G e o m e tr id a eThe geometrids are com m only know n as the looper m oths or inch w orm s because o f the way the ir larvae b ring the ir rear pro legs up to t lie ir fore pro legs w ith the

Species n a in e . . C om m on, n a m e

A p h a r it is n iyn iiec o p h ilc i Dumont De.sert leopard

A n tb e n e a n u n 'a b a m a r a h (Guerin-) Leaden ciliate blue

L am p id es hoen'ciis (Linnaeus) Pea blue

T a n ic iis i-osaceiis (Ati.straut ) Mediterranean pierrol

T a riic u s b c ilh au ic iis (Fre>er) Balkan pierrot

Zi=L‘e n n b a rs n m h n b a is i i i id n i Asian rass blue( Moore )

A 2:n n u s u h a lc liis Cramer

A zcm u s Jesons (Guerin)

A<^rudkicli(s lo e u 'ii ssp. Zeller

C b dtides p a r rb a s in s (Fabricius)

Vr'het .spotted blut

.A.l'iiean babul blue

Loew s blue

Small cupid

h'rcyerici tm cl.iyh is Iro ch yh is Kreyci Grass jewel

L o c a li ty

LIAH (Brown 1992)

Shargiyin (Larsen 1983)

Al Ain, Jebel HaFit, Dubai (Larsen 1983),UAE (Brown 1992),Das Islanil (Reaney 1987, Western 1988)

'Trucial Coasts", Fujairah,Al Ain (Larsen 198.S), l.IAE (Brown 1992)

Wadi Al Jizzi (T.ar.scn 1983), UAE ( Brown 1992),Das Island. At Khazna (Reaney 1987)

Al Ain (Larsen 1983).IIAE (Brown 1992),Das Island (Western 1988, Reaney 1987)

LIAF ( Brow n I V92)

Khor Fakkan (Larsen 1983). UAH ( Brown 1992)

UAE (Brown 1992)

Al Ain, Fujairah. Dubai (Larsen 198.3),UAF. (Brovin 1992),Das Island ( Reane\ 1987)

Meravi ah Island ( Bn >wn 1990). IIAF (Brown 1992)

Table 10.7. The blue butterllies ot I I.AE

^ j j j y i J i j W V - ) . J jo , .iWi.ll

Species n a m e

U c in a iis c b iys ip p iis cbrys ipp iis ( Linnaeus)

C o m m o n n a m e

Plain tiger or milkweed

\ 'anessa c a r d u i c a rd m ( Linnaeus) Painted lady

J u u o u ia o r itb y a berc Lang Blue pansy

H y p o lin iiia s m is ippus (Linnaeus) Diadem or egglly

y p ib im a h n ia n ic a Marshall

U ip p a rc b ia p a r is a t is ( Kollar)

Baluchi ringlet

White-edged rockbio^\ n

L o c a lity

Felij. Abu Dhabi Das Island (Reaney 198' ).Meraw ah Island ( Brown 1990) Al Ain, .AI Ain Al Faydah, LIAE (Brown 1992)

Das Island (Reaney 1987), Meitiwah Island (Brown 1990), Al Ain Zoo. Baynunah, UAE (Brown 1992)

Das Island ( Reaney 1987),Al Ain, UAE (Brown 1992)

Das Island (Reaney 1987). UAE (Brown 1992)

Al Ain Zoo (Brown 1992)

Das Island (Reaney 1987), Dibba—Masafi road (Brov ’n 1992)

Table I 0.8. Ths nympi lalid iTUtlerllies 11| 1 C\E

jjllll jStjilt A - t .

ÂHjdi C jijUyi ^ Nym phalidae

A I ' K H I . I M I N A K ' . A .SS CSS M K N I ' O F T H E A E T 1 I K < ) l->< ) D s ( ) I- A H U D H A B I

22T

body fo rm ing u loop w lic n moving. The on ly records Foi the UAE me both fo r E np ithecia n ie k ra iu i c in iim /is W iltsh ire from "T rnciu l O m nn” and Masafi (W iltsh ire1986). In general, geom etrids w o u ld be expected to have a w idespread occurrence w ith m any species feed ing on cu ltiva ted and oas is-dw e lling plants. For example, the jasmine emerald Cblorissa c/iscessa W alker is o ften found in oases where its larvae feed on C lorode iic lro ii /'/?e/v;/e(W iltshire 1990).

S u p crfa m ily B o m b y c o id e a F am ily L a s io ca m p id a eLasiocampids are com m only know n as eggars and their lanxie are usually covered in dense hair. In some species the hairs contain a poi.son that can cause an irrita tion if touched. Chilenn lansta>ia Daniel is found in sandy desert areas o f UAE where its laiwae feed on Ccilligom ini com osiim (W iltshire 1990). Strebloie s ira Lefebvre, the Jujube lappet, is one o f the commonest species in Eastern Arabia and has been noted at three coastal locations: Ras Ghanada (ow n ob.seivation). Das Island (Reaney 1987) and Merawah Island (B row n 1990). Lasincampci s'em ila palaestinensLs Staudinger has been recorded in Masafi and w ou ld be expected to occur elsewhere in E^AE (W iltshire 1990). 'J'rnniinda m im dissin ici W alker is a w ide ly occurring species across Arabia and has also been found in UAE (W iltshire 1990)

S u p crfa m ily S p h iiig o id e a F am ily S p h in g id a eS phingids o r haw km oths are some o f the largest moths and the ir bodies are covered in th ick scales g i\ ing them a fu rry appearance. The da y-fly in g M cicroglossiin i stelU itc irnn i Linnaeus o r hu m m ingb ird haw km o th has been seen at Ras Ghanada (ow n obser\ a tion ), Das Island (Reaney 1987), Hatta and D ibba (B row n 198-t) and Al A in ( G ille tt 1993) and is probab ly a m igrant from no rthern O m an w here it breeds (W alke r and Pitta way1987). d c6 erm 7 / /r/ .\V t tv West w o o d . the Eastern death's- head haw km oth (Plate 10 13). frequents oases and towns, and is know n from Al A in (W ingate 1992, G ille tt 1993), Das Island (Reaney 1987) and Abu D habi (B row n 198-j). It is \'e ry large and makes a curious squeaking noise by passing air through its spiracles when disturbed. D a p h n is i ie r i i Linnaeus, the o leander haw km oth . is fou nd w h e re \’er its la r\'a l food p lant, N e riiin i sp. or oleander, is abundant (fo r exam ple. Das Island (Reaney 1987)). O leander is a com m on ornam enta l shrub in tow ns and cities but also occurs natura lly in some wadis (J. B row n 1991 ). The silver-striped hawkmoth/7//?/?o//o77 ce le iio Linnaeus has been recorded at Al A in A l Faydah (W ingate 1992) and the striped hawkm oth Z;/)7e.s'//7'0/v?/C77 Esper at Abu Dhab i (B row n 1979) and Al A in (G ille tt 1993). The convo lvu lus haw km oth A g riiis c o n ro lv ii/ i i Linnaeus is kno w n from Abu D hab i (B row n 1979).

S u p crfa m ily N o c tu o id c a F am ily L ym an triid aeLym antrids are know n as tussock m oths and Casanici L'ilis (W a lke r) is recorded as com m on in UAE and no rthern O m an (W iltsh ire 1990).

F am ily A rc tiid a eThe arctiids or tige r m oths are b r ig h tly co lou red w h ich serves as a w a rn in g to vertebrate predators since many are po isonous w hen ingested. The d a y -fly in g crim son speckled foo tm an Utelbeisa p tilc b e lla Linnaeus has been recorded on Das Is land (Reaney 1987), Q arnein Island (B row n 1989b) and at A l A in Zoo (W ingate 1992).

F am ily N o c tu id a eThe noctu ids o r ow le t m oths fo rm the largest fam ily in the o rder Lepidoptera. H ow ever, the o n ly record for UAE is o f a s ingle exam ple o f H ete ropa lp ia ve liis la (W a lke r) from Sharjah (W iltsh ire 1988). The lack of records is u n lik e ly to be due to the ir ra rity but rather because noctu ids are noctu rna l and genera lly a drab b ro w n or grey co lou r and so o f litt le interest to most co llecto rs The larval food plants are o ften grasses and some noctuids are agricu ltura l pests, such ^f^Spoduptcru /7V/07Y7/7S B oisduval, the co tton leafworm .

Fam ily P sy c h id a eO f the p sych id sA iid c ta D iiir in a K lug has been found in UAE. Its larva makes a four-s ided sack o f tw igs for p ro tec tion and these are com m on ly seen in desert areas around Baynunah and M edinat Zayed in Abu D habi on Jlrdo.xy/on s c ilic o n /ic iin i and H. p c rs ic in ii (Plate 10.14).

O r d e r H y m e n o p te r a

The o rder H ym enoptera includes all the bees, wasps, ants and sawfJies. The sawfJies are members o f the suborder Symphyta whose adults d iffe r from those o f the suborder Apocrita (bees, wasps and ants) by the lack o f a m arked cons tric tion bef^'een abdom ina l segments one and two. They are phytophagous rather than preda to ry or ]ia ras itic and there are no know n records o f the ir occurrence in UAE p robab ly because they ha\ e been ove rlooked .

A lthough some o f the Apocrita are so lita ry, many bees, wasps and ants characteris tica lly live in h igh ly organised, social colonies where most o f the ind iv iduals are sterile, fem ale w o rkers o r sold iers w ith on ly one or a few specia lised females and males capable o f rep roduc ing . The H ym enoptera contains some o f the most h igh ly advanced an im al societies. In most cases, the larvae are apodus ( legless) w ith small heads. They have lost the a b ility to m ove since the adults p rov ide them w ith all the necessaiw food or food stores fo r the ir

A l'IŒLIMINAin- ASSliSSMLNT l)F THF, ARTHROPODS OF AHU DHABI

-224

i

i

Plate 10.13. Ku.slern tleath's-head hawkmoth A chen>tiiU i siy.x We.stwoocl at rest on a PiXK-tcfpis tree. Its cryptic coloration allows it to blend in with the bark of trees and so avoid predation.

AcberoiUia siyK I j j j sjjj ji tr - t . i»jl l«ji jll j! .Pmsopis kJtt i ^ fin Westwood

j U J jb-Ail .U Jljï 4- ^

Plate 10.14. Uirval case of the psychid A inictc i i i i i i r h u i King on Hcilo.xylou fx.-is iciim .

Amicta muiiiui klug ÂVU Ujj 11- \ . ■//cilwcylon persiatm ij*»-i Jc- Psychidae kliUli

Plate 10. IS. PcircipsciiiiinophiUi t iira iiic c i Morawitz is one of the solitary sand wasps found in Abu Dhabi's de.serts

Parapsammopbila turanica Morawitz 'o-l •^ ^ , ^ > 7 1 d.ji _*uj A.I

/VU

\ I ’ K I - L I M I N ■\K' i ‘\ S M - S S M 1 - N 1 O I - I I I I-: A I M ' I I K O l'< ) l ) S ( ) I- M i l l I J i l A H I

225-

(.lc \e lopm ent In the deserts ol Abti D h iih i, ants are particu larly numerous anil form an im portant part o f the d iet ol many p re ila to ry in \ ertehrates and vertebrates Some ants are sca\ engers erf carrion and w ill soon strip any carcass that they find , w hile others are specialist seed-eaters and the ir e ffic ien t forag ing leaves litt le on the surface o f the sand. Many o f the sm aller wasps are parasitoids, laying the ir eggs on a liv ing host The wasp laiA'ae then develop inside the liv in g host, usually resulting in its death. Some species are parthenogenetic atid femtiles are able to lay v iable eggs w ith o u t the need to mate, Parasitoids have not been studied in UAE in any detail and are re la tive ly unknow n in Ara liia as a w hole

S u b o r d e r A p o c r i t a F a m ily A n th o p h o r id a cThe anthophorids gather wood pu lp to construct their nests and are com m only know n as carpenter bees. I'hey are large and \ ery noisy fliers m aking them quite conspicuous. The fo llow ing ha\ e been recorded in Abu Dhabi: ( Friese ), AniegiUa hyssiiui( K lug). I ’i lh it is tcirscita ( Mor. ) and Xylocupnpiihesccns Spitio la (Ham er 19(S6). Xylocopci/eiicstrci Pabricius was recorded from lla tta ( I lam er !9<Sh)

F a m ily M e g a c h i l id a eThis family includes the leal-cutting bees and se\eral species have been collected from \arious localities in HAP (Hamer 1986 and Table 10 9)

S u p c ifa m i ly C ih iy s ic lo id c a F a m ily C h iy s id id a cChrysids are commonly known as cuckoo wasps and tend to be bright, metallic green or blue in colour The\ are fast llie rs and are stnall to m edium in size. Koche (1981) collected a po.ssible 11 species from the fo llow ing genera in HAP Cicptiiicie. Chiysis Purnopes. H o ilych rid inn i. Heclychnmi and Onutliis

S 11 p c r fa m i h V c s p o ic lc a F a m ily P o m p i l id a cThe pom piliils are known as the spider-hunting wasps. They are m ainly confined to stony locations such as wadis and gra \e l plains The females provision their nests w ith spiders that they paralyse. The spiders do not

immediately die but act as a liv ing food store for the de\ eloping wasp Ian a The males do not hunt spiders but feed on flowers and po llen and are very fast flying. Se\ eral un identified pom pilids were collected by Roche(1981).

F a m ily S c o liid a cThe scoliids are know n as beetle wasps. Roche (1981) collected between two and four species from two genera Scolia and E/is. It is often d ifficu lt to tell which males and females belong to the same species because o f the marked sexual dimorphism.

F a m ily E u m e n id a eEumenids are semi-social o rso lita iy w asps. The fo llow ing species have been recorded in Abu Dhabi by Hamer(1982): Cl.doroclyiienis c/.T/oriticus (Spino la), Della canipcin iforn ieg ra c ile iS-Aussuve), Della c lin iinua tipen iie (Saussure). D e lla b u lle iito ta n i elegans (Saussure). Etioclyneriis e.xcelleiis (Perez) and Eiiocly)ienis iiilo lic iis (Saussure)

F a m ily V e s p ic la crhe.se are the true wasps that li\ e in social colonies Richaids ( 198-tb) has records for three species: Ves/)a orie iila lis arieiila li.'i Linnaeus and Fulislcs iiu lic iis Stolfa at AI ,Ain. and Folisles ir a l l i Cameron at Hatta.

SVIbfamil\ Ma.sarinaeThese are wasps that feed on pollen and Mowers The fo llow ing have been recorded in HAE by Richards (168 ta): (J iia il i i/ ia m ih ia iia Richards at Hatta and As Saad. Celonilesjotisseam iiei R du Huys.son at As Saad.

J i i g i i i l i a Jeniei/e iisi .s Kostylei at Hatta

Family^ F o r m ic it ia cAnts are an im portant eco logica l group, some o f w h ich are w ell adapted to desert cond itions w h ile others can on ly survive in irrigated areas and oases In spite o f the c osm opo litan occurrence o f ants, few records exist for the M idd le East and e\ en few er fo r ll.AE Surveys ol Saudi Arabia and Oman have found 156 and 28 species respectively (C o lling w oo d 1988, 1988) and recent material has boosted the total num ber o f ant species in Arabia to around 278 (C. C o llingw ood in l i l l . ) . Table 10.10 is based on T igar and C o llingw ood ( 1993) atid

Taille Ida; r t ie leal-o.unn.t> tivcs

Mexai liiliLlai n f rom I 'A t ' tVisi il on

I l.iinei ( I VN(,)

M fi'aO iiiidac VLUU j p l ^ U li <l-\. ; a ^ l V u jJ I O IjL -V I j . . .

Species n a m e

A lc g a c h ile p c ite llin ic iiu i Spinota Me,L(ac/.}ile u 'c ilkeri lA. Tor. M e p a c h ile in iilis s iiiu i Karl C h alicoctonu i n ih rip e s Mor C re ig b lo n e lk i an ic ih ilis (Civil. ) M e s a u lh ic lin m a l/c r iu is (Klug) .4 ii/hcicapa h e /o iifu .'ia (I riese)

Lo ca lity

Abu Dtnatri MaltaAlsu It)ha hi Hatta Malta I tall a AI Ain

191

A i >K i i . i M i N A i n a s s i -:s s m i ; n i l i t - I i n - a k t i i k ( •)!><.) n s o i - m î t i a i i m ü

226

Species n a m e

Subfam ily M yrm tcm ae

M essor e b e n in n s I Orel Aiessor rn /u les lac e iis Foer.stt-r C'rei)ia/Of>cister a i ita r is Fore!A io iio in d r iii I I I abe iU ei Anil re A k m o n io h in n tu a y r i Fore I A lo n a n to riu n t l i in u i ir i Collingwoocl ( in b it ) M o iio n io n ii in iir ib ib ie n s is Collingwood ( in /ill.')

Subfamily Formicinae(b in ip tin n lN s .w r.w .i Fore I

Ckilci,iilypbis b r id a André C a ia g irp h is n ig e r (André)

C a la g /ypb is J /a ro b n m n e n s Collingwootl ( in b n .)C a ia g /)p b is m in im a Collingwood ( in bn ) C a ia g ly p b is sa /m /n sa Kugler A c a n lb o /e p is nigrescens K:ir:iw:ijew

Locality a n d recorder

Ras Glr.inada Island (Tigar)2--l°46.R'N Sh°SS.3’E (Tigar)2-)°a6.S'N Ai°5T.3'E (Tigar)Ras Ghanada Island (Tigar)24°4b.H'N 3 °53.3'E (Tigar)Jebel Halu (Heatwole). Ras Ghanada Island (Tigar) lebel Halit ( HealAvole), Ras Ghanada Island (Tigar)

Ras Ghanada Island (Tigar), .AI Ain Al Faydah Hotel and Fark (Wingate)lebel Halit ( Heatwole). Ras Ghanada Island (Tigar) Al Ain Zoo. Al Ain Al Faydah Hotel anil Park.AI Wigan (Wingate)lebel Halit ( Heatwole), Ras Ghanaila Islanil (Tigar )

2 t° ib.S'N 5+"3t.3'E and Ras Ghanada Islanil (Tiiaar) lebel Halit (Heatwole). 24°h(-.,.S'N ôa°Â5.,VE (Tigar) Ras Ghanada Island and 2 t°-t(i.H'N 3'E (Tigar)

I'alale I () I () List i it atit spi-i

rent in lei I h i un ,\ln i I )h.ibi

Finit ate

ijt^i j*iii j-ty ■ J jA -

Species'^ ”I -xii-wtJH ■ ' . •- I 1- i-S ■ ■ ■>>-■«- ' L. - . .C b /o rio n sem en o ivt o c c u /e n ia le Beaumont C b /o rio n b ir tn n i (Kohl)C /ylorion J in io ro u m CjiibodoC b a l) •bionJle/jite ( Lepeletie de Sa int-Fargea it )S cebpbnm m a d ra s p a ia n n m p ic ln m (S m  )S cebpbron p iiicb ic lb im re c ln m KholS p b e x fn m ic a tn s ChristSpbe.x p rn in o s iis GermarS pbex / la r ip e n n is FabrieiiisP r io n y x c n id e /is SmithP r io n y x n ire a ln s (Duloitr)/^ r io n rx r i i /n a ln s (Christ )/k ira jjs a m m il/lb i/a I l ir a n i r a P re im icb ares sp.

/^ iid a /im ia iy d e i (Le Guilloit)A m m u /> h i/a /ja o c i/iic iie m is Mot iee A m m ii/ ib i /a e i in in e a Kohl A m m o /)b i/a g r a d / / i m a Tasi henbetg A m im i/ i / i i /a r iib i/ies Spinola


Al Ain ( Brown )Near Dibba (Roehe)Wadi Mor. Jebel Ali, Shweib (Hamer)Dubai, Abu Dhabi ( I lamer)Hatct. Khor Fakkan. Waili Asitnah ( \ lamer. Roehe) Hatta (Hamer). Hatta ( Roche), Al Hyayntth ( Hamer) Widespread ( G nicha til )Abu Dhabi (Roche)Al llyaynah ( I lamei )Widespteail ( Giiicharil )Widespi ead ( Guii hat il )Abu Dhabi. Hatta ( I lamer 19B6)As Saad (Roche)Abu Dhabi ( Roehe). Futaisi Island ( I Lmii i ) Widespread (Guichard)Asimah. Khoboos-Kawan (Llaniei )As Saail (Roche)Abu Dhabi. As .Saatl. Hatta (llami-i I9S(i )Abit Dhabi. As Saail. I lalta (Hatner 19H(i)

Table lO II Recot ils ol the subI.imiK Sphecinae Irom the HAE. taken Irom Guii haril I iu.SiSa) unless otherwise

siitc. ■ - i-v'll .*,*-) 1- ./i ) ) ~ ) , d jA i

; .iAilJl CiijlaV' ^ S|ilieiinac jji. J,I jdtl tji VI Guichard ( l9KKa)

.allj

Species

D ry iu /e //a tr ic o /o r (V„\r\ Linilen) n iy i id e / /a i ie p b e r li li (Pulawski) P )iy iid e //a n s ir ic a (Pulawski /:> iynd e//a h ifa s c ia la (Pulawski)

Locality

Abit Dhabt. Hatta. Al Markhaniyalt Al Markhaniyah Al M a rkhaniyah AI Markhaniyalt

I aisle 10,12 Ki-i oi'ils < >1 the

sublamily Astatinai- Irom the

ILAF. bas iil on 1 Ltmei i lO.S.S)

dilt aurt.i./, D - i . Jjaa jc .iAguli iajdi ejtjt-yi y Aslalinac

.l-laiiiiT ( 19SS)

incorpoTdtcs the icco ids ot Heatwole (1991) aiiU ohseiA arions by \X ingaie ( 1992) O nly l-i .species are listed and they are probab ly on ly a small p ropo rtion o l those that oecnr They range in habits from com m on honseho ld pests, such as members o f the genus M o iio n io r iiin i. night foraging ants such as Ciin ipo i/o /ns .wr.xos Forel. to those that are h igh ly adapted to the descri environm ent, such as the genus Ci/taglyphis w h ich can forage even du ring the heat o f the day. The species list a lm ijst certainly re 11 eels the areas where the ants were collected u hieh included a residential fie ld l eseareh station as w e ll as several desert areas around As Samhah, A l A in and Ras Ghanada Island, all in Abu Dhabi Tmirate. Doubtless many more species wait to be recorded in the Emirate

S iip c i fa m ily S p iic c o ic le aThe family Sphecidae comprises small to medium sized solitary wasps that make their nests by digging tunnels in io soft .sandy banks (Plate lU. Is). They capture and paraly.se other insects w ith their stings to proxasion theii nests. Some families and e\ en genera ha\ e been fairly w ell w orked for L'AE by Guichard ( 19HSa. 19HSb, 1989a. 1989b, 199.4). Twenty-seven species o f Zlc/)//;/.vare listed for the Arabian Peninsula o f w hich 16 ha\ e been found in UAE. O f the three species o f S'/fro/V/es. tw o are found in UAE and fix e o f the 12 known Arabian S/iziis have also been recorded. UAE records are particularly p lentifu l from the Sweihan road and from Abu Dhabi, although this probably reflects intensity o f collection rather than abundance o f the wasps themsehes. Tables 10.11 to

/o j

A l - K U l I M I N A I O A S . s l „ S . s M i ; \ I O T1 I i : A K l I I K( > l ' ( ) O S ( ) I \ H I D H A l i l

227

I ih ic lO lA. Kun xils wl tliL

suhhiniily L.iiriti.ii' IVoiii ihc I lAI:. Ii;isn l 1111 I liiniui ( I'J.s.s)

un ie » o iIk tw isi.- suili il

üilxi ' V- \ . J_,i,

j t eji jU"!(l Uirriniie

J ! ij) V) llum er (1988)

Species

I . i r i s (i/L>i/is (f-'. sin)/Jris a ln ia la (Spinohi)U ris n i^ ra Kohl/. i / is iti^ i ic a us (Walker)L iris prcieleniiissct ( Kichartls )U ris s iib fa s c ia tti (Walker) G cislniscricus elcclus Nurse G astrosericus m o r ic t i (E. Saunrl ) C astrosericns s u u c /n s Pulawski Gcis/roseiicus u n / f / i t Spinola Tachytes com f ie ri Turner Tachytes cH i'e ts ico ru iau u s Turner Tctcbytes u i/o tic iis Turner Tachytes p ig m a e u s Kohl 7’cicbyles s iu t ia liis Pulawski Tachytes tricbo pygus Pulawski Tacbyspex a lh o c iu c tu s (Lucas) Tacbyspex cheaps de Beaumoni Tachyspex costae (De Stef.) Tacbyspex e ry th ro p b a n is D. Tor T acbyspex e iy tb ix jp iis (Spinola) T a c b y s p e x fu /t ic o ru is Turner Tacbyspex g ra n d is s im n s Guss Tachyspex in certu s (.Rad.) Tacbyspex m aicH i de Beaumont Tachyspex m y c e rin u s tie Beaumont Tacbyspex n itid n s (.Spinola) Tacbyspex osiris de Beaumont Tachy spex p a lo p te n is ( Da hi ) T a c b y s p e x p u lc h e r Pulawski T a c b y s p e x p a n z e r i (Van Linden) Tacbyspex rttgosus Cuss P a la rn s d an g a le n s is Klu.q P a ia ru s sp iu o la e sp in o ia e Saussure PaU trus iaetus Klug P a la rn s p a re u h is de Beaumont M iscopbns ctenopns Kohl .Miscopbns h e lre tic n s Kohl M iscopbns im ita n s Gin Mar M iscopbns in im e tic n s Hon T iy a x y /a n a e g y p tin m Kohl T iyo xy /o n a ra b ic n n i Guss O xybe/ns la m e /la /n s Oli\ iei (Xxybe/ns c o /ia ris Kohl Oasy/>n>ctiis a ra b s Kohl


Abu Dhabi, Hatta Abu Dhabi. Liwa Abu Dhabi. Hatla Abu Dhabi Abu Dhalii HattaAbu Dhabi, As Saad. Hatta. Sweihan Abu Dhabi. Sweihan Abu Dhabi, Hatta Abu DhabiAs Saad. Al Markhaniyah, Shweil->-Al Madam roadAs Saad. HattaAbu DhabiHattaHatlaHattaAbu DhabiAbu Dhabi, Hatta, Shwell>-Al Madam road Abu Dhabi Abu DhabiAl Ain. Abu Diiabi. As Saad, HattaAs SaadSweiiianHatlaI lattaAbu Diiabi, Al Markhaniyali, Sweihan As Saad. Hatta As Saad HatlaAs Saad, SweiiianAbu Diiabi. As Saad. SweihanHatlaAbu Dhabi (Hamer). Abu Dhabi. As Saatl (Roche) Hatta. Shweib Al Madam road (Roche) Widespread (Guichard)As Saad. Shweils—Al Madam road ( Rot he )Abu Dhabi, Sweihan, As SaatlSweihan. As SaadSweihanSweiiianI lattaHattaAbu Dhabi. As Saad. I latta. SweihanAl Ma rkhaniyahHatta

r.lblc it) i t. Recortls ol the subfamily Nyssoninae Irom the ( lAE. taken Irom GuichartI ( lOSOa) unless otherw ise

i lilc Cis'.ll . l i i L ^ t fc - 1 .

^ j d i .jijL .y t Ny,s.sonin:te jd .\ G V) Gtiich.-trd ( 1989a) >

Species

A m m a to m n s mesnstenns ( Hantlerlirshe) A m m a to m n s rn jo n o d is (Radowski) l ie m b ix tra n c jn e b a ric a (Gmelin)

B e m b ix g a z e lla G ttichard B e m b ix saadensis GuichartI B e m b ix c h a p a rd i BerlantI B e m b ix fre y g e s s n e ri Mtirice B e m b ix d a b ib o m i Handlirst11 B e m b ix c b lo ro tic a Sptnola B e m b ix o c n la ta La tie II le B e m b ix n ig r is /iin a Guithaitl B e m b ix ra d a s zk o n s k y i I lantllirsch B e m b ix rn f ire n tr is I’riesner B e m b ix p r ie s n e ri Beaumont

B e m b ix p a l/e s c e n s Priesner B e m b ix hbo lt Monte B e m b ix n H o tica Priesner

B e m b ix m c b i GuichartI

B e m b ix b a m e t i GuichardStizo id espoec i/op terc is HanderlirschStizns c itr in n s KlugStizns fn s c a tn s Mot iceS tizns b iz o n a tn s SpinolaS tizns n a d ig i Roth in NailigStizns rn fic a rn is (Etirster)Stizns s a i'ig n i Spinola Stizns a ra e ic n s Guichard

Localiiy a n d recorder

Hatta (Hamer 1988)Hatta (Hamer 1988)Shweil>-Al Matlam roail (Rociie).Sweihan road (I lamer)Shweib-AI Matlam roatl. Sweihan road (Roehe)As Saatl (Roche)lebel Ali and Ril'aa (Hamer)Witlespretitl (Guichard)Witlespread (Guichard)As Saatl (Roche). Sweihan rtiatl (I lamer) Witlespread ( Guichai tl )Sweihan Roatl (I lamer)As Saad (Roche)Hatta ( Rot lie)As Saad. Shweil3-Ai Madam road. Al Marklianiyah ( Roche). Jebel Diianna, Sweihan (Hamer)As Saatl. Abu Dhabi. Sweihan. I latta (Hamer 1988) As .Saad. Al Marklianiyah (Roche)Abu Dhtibi. Sayh Huwayyah. Shweili—Al Matlam roatl (Roclie)Siiwtib—Al Madam rotitl. Sweihan road. As Saatl. Bitia Al Ajam, Al Marklianiyah (Roche)Sweiiian (Hamer)Aiitt Dhabi (Roche), Hatta (Hamer 1988)Hatta (Hamer)Abu Dhabi (Hamer)Abu Dhabi (Hamer and Roche)Shw'eili-Al Madam roatl (Roclie)Sweiiian road (Hamer)Shweib-Ai Madam road (Roche)Abu Dhabi, Lullat'yah, Jebel Ali, Khor Pakltan (Hamer). Hatta (Rot he )

19 A

A I ’ K l i L l M I X A I O AS.M;sSM1:N I O f I I I f AK I I I K O l ’ O n s Of- AUf | - ) t f \ l^ l228

Species

F b ila n th n s coe irctanis Spinnln F h ila u tb u s ^ e ita lis Kolil P b ilc n itb u s p c illid u s Klug I 'b ila n tb u s Ir ia itj^ t ilu in (Faf-)riciu.s) C ercens a lb ic b ic ic i Klug C erceris c b ra m a tic d Sell I

Ce> -cens f is b e r i Spinola C erceris Iciterip ixiclucrn Moc hi C e rc e ris J 'itx g e ra k li Empey C erceris bcin io ri Guichard C erceris In rkestc iiiicn Rndoszkowski Cerceris a lb o a trc i Walker C erceris s t ra n iii ie a Dufour C erceris uittalci eitrypgct Kohl C erceris iiugcj.x Arnold

C erceris e n g e n ia Schlellerer C erceris d iff ic il is Guichard C ercens v a g a ta Kohl Cerceris s o lH a ria Dahl C erceris tricu lo irilc i Spinola

Lvccdity a n d recorder

Al Ain, Abu Dhabi, A.s Saad, Haifa (Hamer)

Abu Dhabi (Hamer.)

Abu Dhabi, As Saad ( I lamer)Abu Dhabi (Hamer)Abu Dhabi, As Saad, Sweihan (Hamer)Abu Dhabi, As Saad (Hamer), Sweihan. Sh\veil>-Al Madam road (Roche)Abu Dhabi, Hatta (Hamer)Abu Dhabi. As Saad (Hamer)Abu Dhabi, Remah, As Saad, Jebel Ali (Guichard ) Sweihan, Remah (Hamer)Ilayl (Hamer)Wadi Asimah (Hamer)Al Babha(Roche)Sweihan road, Dubai—flatta road (Hamer) Shweili—Al Madam road (Hamer), (Roche) Sweihan road. Al Mtidam road. Al Awir—Mileiha road (Hamer)Sweihan road ( Hamer)Hatta (Hamer)Wadi Asimah. Kalba, 1 lallti (Hamer) flatta (Hamer)As .Saad. Hatta, Abu Dhabi (I lamer)

fable lO IS Recoiils ol the

subl'amily I’ hilanihinae From

the LIAH. based on f lamer ( Ib.S.S) and ( jn il hard ( 1003 )

djU. ) 0- ) .^ jd l Ciljt-yi I’hilantliinae

• Guichard ( 1993) j I lamer ( 198K)

10. Is list by subbim ilic.s all iccorcls o f sphccicl species reeoixled in the Emirates. T h irty three species ol Ccrcdris ha\ e been foun(.l in .Arabia o f w hich 16 occur in V.\E

S L ip c r fa i i i i i> A p o i t l c a

F a m i ly A p ic la c

Members o f the apid fam ily are the fam iliar and economically im poiian l honey bees, such ;is, l/)b iiic llifen i lannaeus that is kept in commercial hi\es. The small •Asiatic honey bt'c ApisJlo ivd Fabricius has also become established in Abu Dhabi ant.1 is reporlcxl to be the most com m only occurring honey bee (1 lamer 19.S2)

Cda.s.s C r iis ta c :e a ( c fc is ta c e a n s )

The Crustacea are characterised by ha\ iiig tw o pairs o f antennae, three pairs o f m outhparts and many leus. Most Crustacea are aquatic, fo r exani|)le crabs, praw ns. lobsters and shrim ps However, a lthough the o rder Isopoda generally contains many marine or Iresh-w ater dw e llin g species, it also has some that are terrestria l and surpi is ingb ' do occur in desert en\ ironm ents

C la s s C h ik ) | ) ( ) c la ( c e n l ip e c ie s )

The cla.ss Chilopoda are m yriapodous arthropods. i,e the) ha\ e many le.gsand were form erly grouped together w ith other similar arthropods. They are prcdaton and reh ili\e l\ sofl-bodied Their bodies are dor,so-\cntra lh flattened and the head possesses a pair o f simple antennae, a group o f simple eyes, three pairs o f mouihparls and one pair o f poison glan(.ls. The rest ol the bod\ consists o f numerous segments each ol W h ich bears one pair o f legs .Some species can give a painful bite though it is not likely to be very serious. To date, onh the order Scolopendromorpha has been foun(.l in Abu Dhabi, bui a few Ceophilom orpha may also occur. Lewis and Gallagher (1993) list four locations for S a ih ifd iid ra iiiirc ih i/is (Porat) in CAF anil Scolopcmlm I'alidci Lucas once in Sharjah. Nine species ha\e been recorded in Saudi .Arabia and there is no reason to suppose that those occurring in Abu Dhabi are different species. They are not thought to be especially well adapted to the desert, are nocturnal and are not usually seen (.luring ifie day unless disturbed un(_lei stones and other refuges (Lewis 19,S I)

O r d e r I s o p o d a ( i s o p o d s ) P o s t s c r ip t

Tw enty species o f terrestrial isopods have been recorded fo r the Arabian Peninsula (Taiti and Ferrara 1991). Dcsert-dw e lling isopods from the fa mi I \ Porcellionidae. com m only know n as wood lice . have been found in Abu Dhabi, although the ir identity is unknow n They sun ive by constructing special burrow s that a llow them to m aintain a m icroclim ate w ith su ffic ien tly high hum id ity du rin g the day. They emerge to forage on the surface o f the sand at n igh t (Lewis 198j ).

ln \ ertebrates form one ol the most numerically important groups in arid regions and show a irem endous \ ariety of structure and lifestyle, besides their direct contribution to desert b iod ive rs ity , they are undoub ted ly im portant in the food chains o f \ ertebrates such as reptiles, birds and mammals. Yet invertebrates remain poo rly studied and the even the most basic co llecting can help im p iove ou r know ledge o f them in Arabia. The in fo rm ation in this chapter is based on the data a\ a ilab le up to

A PRELIMINARY' A.S.SES.SMENT OF THE ARTHROPODS OF ABU----------------------------------------------------------------------- 22y-----

February 1994, bu t the s itua tion is rap id ly changing. NARC’s studies on the feed ing eco logy o f the houbara bustard inc lude a m o n th ly program m e o f p itfa ll trapp in g at five sites across the Emirate. D is tr ibu tio na l records o f the invertebrates caught are stored on a database fo r easy re trieva l and sorting. By Decem ber 1 9 9 4 , the database con ta ined 20,368 observations o f invertebrates from ove r 200 species, m ostly ground- d w e llin g species and desert specialists. W herever possib le, id en tifica tion s are be ing carried ou t w ith the he lp o f in ternationa l experts, fo r exam ple, at the Natural

H is to ry Museum , London, bu t th is is becom ing the lim it in g factor. Inve rtebra te taxonom y has become unfashionable, the rem aining experts often being retired pro fessionals w h o con tinue the ir w o rk as a labour o f love. Abu D h ab i’s geograph ica l pos ition at the m eeting z o n e o f th re e b io g e o g ra p h ic re g io n s m akes id en tifica tion s especia lly d if f ic u lt and the reference m ateria l itse lf is p o o rly w o rked . A ll too soon, it w ill no longe r be possib le to f in d experts w h o kn o w A rab ia ’s invertebrates. New species and form s that are today und iscovered may be lost fo reve r in the sands o f time.

230

Appendix 1.2

Terrestrial Arthropods (excluding insects)

by Tigar, B. J. (1996b).

In: Vine, P.J. (ed.) Natural Emirates. Pp 107-120. Trident Press, London.

Terrestrial Arthropods (excluding insects) Bmimrn Ti^nr

Argiope, the orb or

signature spider,

packaging its prey.

The zigzag anchoring

chords may serve to

draw the attention of

a potential victim

away fiv iii the web

which captures it.

T he f l o r a a n d fa u n a o f th e UAE contain a mixture of elements from three

major biogeograpluc zones: the Northern Palaearctic, Africa and Asia. This,

in combination with an extremely dry climate, results in a characteristic

invertebrate fauna with typical arid-zone species, such as camel spiders and

scorpions, being relatively abimdant. Legends and tales of the terrible scourge

that these creatures cause aboimd. Eadeed, on first sight they look like products

of an araclmaphobe's nightmare, ha this chapter I hope to dispel such myths and

show the important roles these animals play in their environment. 1 also explain

how, tlarough their biology and ecology, mvertebrates are well adapted to one of

the most inhospitable parts of the world: while most humans venture only

briefly from the conafort and safety of their air-conditioned, four-wheel drive

vehicles, the ai thi opods take the desert m their stride, albeit usuag many legs!

H is t o r ic a l r e c o r d s o f t e r r e s t r ia l a r t h r o p o d s

Invertebrates of the Arabian region as a whole remained poorly studied until

the late 1970's, and the UAE still has far fewer records than neighbouring

Saudi Arabia and Oman (see the Fauna of Saudi Arabia series and the lournal

of Oman studies for further details). This is mainly due to the lack of collectors

and records rather than a paucity of fauna, although the other two countries

are larger with greater climatic and biological diversity. In this chapter I have

gathered together all published records and some of my own unpublished

findings of terrestrial arthropods in UAE. I have also added information on

arthropod groups which have not been found in the Emirates but which

probably do occur on the basis of records from neighbouring countries and

sim ilar climatic regions elsewhere. Wherever possible I have included

information on first aid for bites and stings.

A n IN TR O D U C TIO N TO THE ARTHROPODS

The arthropods form a major taxonomic division, also known as a phylum

which consists of invertebrates (animals without backbones) that possess

jointed bodies and limbs, and an exoskeleton. For more detailed information

on arthropod biology and phylogeny see Barnes (1987), Manton, (1977) or

Meglitsch (1967). The exoskeleton or cuticle can either be thin and flexible

forming the joints, or deposited in thick, stiff plates called sclerites which

function like armour. Crack open the claws of crabs or lobsters and you will

know just how strong the sclerites can be. The cuticle also acts as a barrier

against water loss and therefore helps arthropods to survive in arid

environments. Arthropods are further classified according to the similarity of

their body structure, in particular the shape of their mouthparts which reflects

the range of diets and feeding habits.

Five sub-phvla are recognised of which three, the Crustacea, the Insecta-

Mvriapoda and the Chelicerata, occur in UAE. The vast majority are insects,

which differ from other arthropods by having specialised antennae, two pms

of wings. SIX pairs of legs and compound eyes. The insects are described in a

T e r r e s t r ia l A r t h r o p o d s

separate chapter of this book. Here I shall consider the remaining terrestrial

arthropods which are more diverse although they tend to be either predatory

or parasitic animals.There are few species of terrestrial Crustacea (crustaceans) in UAE although

they are more common than might be expected of these generally mesic (ie

moderate moisture) creatures. Besides the vast array of insects, several other groups belonging to the Insecta-Myriapoda frequently occur in arid-zones like

the Emirates, particularly the Scolopendrida or centipedes. By contrast, the

Chelicerata (chelicerates) are very well-represented by various members of the

class Arachnida which again can be divided into 11 sub classes. Of these sub

classes, nine are likely to occur in UAE. They are the scorpions (Scorpiones), pseudoscorpions (Pseudoscorpiones), solifugids or camel spiders (Solifugidae), whip scorpions (Schizopeltida and Thelyphonida), tail-less whip scorpions

(Amblypygi), spiders (Araneae), harvestmen (Opiliones) and mites and ticks

(Acari). In terms of biodiversity and biomass, or the amount of biological

material determined by body size and relative numbers, the scorpions and

solifugids are the dominant groups in UAE. Some of these animals are

predatory and a few are venomous, but they are not generally aggressive

towards humans and only use their poison to kill and capture their prey or as

defensive weapons. Most stings or bites orüy occur when these animals come

into accidental contact witih man.All invertebrates are poikilothermic, or cold-blooded, so their body

temperature is dependant on that of their environment. Activity therefore is

often directly related to temperature and there are noticeable differences in

activity levels between day and night, and the summer and winter months.

Indeed, during the day, deserts appear devoid of animal life and it is not until

dusk that their many arthropodian inhabitants become apparent. Conversely,

during the winter, if the ambient temperature is too low for their basal metabolic

rate or that of their prey, mvertebrates remain inactive and will rarely be seen.

Although most arthropods have a relatively small body-size, their biology is

quite varied and many species show a high degree of specialisation.

Everything from parental care through to complex behaviour and adaptation

to environment are exhibited. In some arthropods, the juvenile stages are exact

miniatures of the adults while in others they not only look very different, but

also have totally different habitats and diets. In order to grow most arthropods

have to moult, known as ecdysis, before they can increase in size. During this

time they are very vulnerable until the new cuticle has hardened.

In terms of classification, I have tried to follow Sheals (1973) and Sheals &

Rice (1973), but there is considerable disagreement in the scientific literature

about how closely related some of the arthropods are to one another. Indeed, it is not always clear at what level they should be split and whether they are

separate phyla, classes or orders. By keeping to one system of classification I

hope to simplify matters and avoid confusion. I shall therefore start by

introducing the various groups, then deal with each in turn by describing their

general appearance, biology, ecology and natural history. Finally, for each taxa, I shall list those species known to occur in UAE. In most cases this consists of a

scientific name because they have no known common name.

Sub-phylum Crustacea

The crustaceans are a very diverse group dominated by marine and aquatic

species. In many deserts, numerous tiny brine shrimps are found in temporary

pools following the rains. These creatures are able to withstand immense

periods of desiccation and reproduce very rapidly to ensure the continual

survival of their kind. Such pools have not been studied in UAE but it is

possible that ephemeral crustaceans do occur. The only terrestrial Crustacea are

die sub-class or class isopoda.

Crustacea Isopoda

Since most isopods are either aquatic or associated with very humid

environments, it is perhaps surprising that the family Porcellionidae or woodlice is common in desert areas. These creatures have small, ovoid bodies

up to about 6mm in length, with two long antennae and a shorter pair of

antennules at the front of the head, and a thorax divided into seven segments. fs>

N

T e r r e s t r ia l A r th r o p o d s

separate chapter of this book. Here I shall conMOcr the remaining terrestrial

arthropods which are more diverse although :ne\ tend to be either predatory

or parasitic animals.

There are few species of terrestrial Crust.rce.r t crustaceans) in UAE although

they are more common than might be e\pected of these generally mesic (ie

moderate moisture) creatures. Beside,- the \ a-t array of insects, several other

groups belonging to the Insecta-M\ riapoda trequently occur in arid-zones like

the Emirates, particularly the Scolopendrida or centipedes. By contrast, the

Chelicerata (chelicerates) are \ er\ well-represented by various members of the

class Arachnida which again can be divided into 11 sub-classes. Of these sub

classes, nine are likely to occur in U.AE. The\ are the scorpions (Scorpiones),

pseudoscorpions (Pseudoscorpiones), solifugids or camel spiders (Solifugidae),

whip scorpions (Schizopeltida and Thelvphonida), tail-less whip scorpions

(Amblypygi), spiders (Araneae), harvestmen (Opiliones) and mites and ticks

(Acari). In terms of biodiversity and biomass, or the amount of biological

material determined by body size and relative numbers, the scorpions and

solifugids are the dominant groups in UAE. Some of these animals are

predatory and a few are venomous, but they are not generally aggressive

towards humans and only use their poison to kill and capture their prey or as

defensive weapons. Most stings or bites onlv occur when these animals come

into accidental contact w ith man.

A ll invertebrates are po ikilotherm ic, or cold-blooded, so their body

temperature is dependant on that of their em ironment. Activity therefore is

often directly related to temperature and there are noticeable differences in

activity levels between day and night, and the summer and winter months.

Indeed, during the day, deserts appear devoid of animal life and it is not until

dusk that their many arthropodian inhabitants become apparent. Conversely,

during the winter, if the ambient temperature is too low for their basal metabolic

rate or that of their prey, invertebrates remain inacti\ e and w ill rarely be seen.

Although most arthropods have a relativeh small body-size, their biology is

quite varied and many species show a high degree of specialisation.

Everything from parental care through to complex behaviour and adaptation

to environment are exhibited. In some arthropods, the juvenile stages are exact

miniatures of the adults while in others they not only look very different, but

also have totally different habitats and diets. In order to grow most arthropods

have to moult, known as ecdysis, before they can increase in size. During this

time they are very \ ulnerable until the new cuticle has hardened.

In terms of classification, 1 have tried to follow Sheals (1973) and Sheals &

Rice (1973), but there is considerable disagreement in the scientific literature

about how closely related some of the artliropods are to one another. Indeed, it

is not always clear at what level they should be split and whether they are

separate phyla, classes or orders. By keeping to one system of classification I

hope to s im plify matters and avoid confusion. I shall therefore start by

introducing the various groups, then deal w ith each in turn by describing their

general appearance, biology, ecology and natural history. Finally, for each taxa,

1 shall list those species kiTown to occur in UAE. In most cases this consists of a

scientific name because they have no known common name.

S u b - p h y l u m C r u s t a c e a

The crustaceans are a very diverse group dominated by marine and aquatic

species. In many deserts, numerous tiny brine shrimps are foimd in temporary

pools following the rains. These creatures are able to withstand immense

periods of desiccation and reproduce very rapidly to ensure the continual

survival of their kind. Such pools have not been studied in UAE but it is

possible that ephemeral crustaceans do occur. The only terrestrial Crustacea are

the sub-class or class isopoda.

C r u s t a c e a

I s o p o d a

Since most isopods are either aquatic or associated w ith very hum id

environments, it is perhaps surprising that the fam ily Porcellionidae or

woodlice is conunon in desert areas. These creatures have small, ovoid bodies

up to about 6mm in length, w ith two long antennae and a shorter pair of

antennules at the front of the head, and a thorax divided into seven segments. 109

N atural Emiiumes

Of the various species

of scorpions, that

occur in the UAE, the

small i/ellow

Buthacus

yotvatensis

iiigroaculeatus

is the most poisonous.

Tliey are detritivores and survive by remaining in the humid micro-climate of

burrows at the base of desert shrubs and only emerge to feed at night. They are

probably relics of a more moist environment.

T e r r e s t r ia l I s o p o d s i n U A EFerrara & Taiti (1985) and Taiti & Ferrara (1989, 1991) list 20 species of

woodlice which occur on the Arabian peninsula. Of these there are two species

introduced by man (PorcellioniAes prunniosus and Protracheneonisus inexpectatus)

and three cosmopolitan species {Porcellio assimilis, Porcellio evans/s and

Koweitoniscus tamei). All of these are likely to be found in the Emirates. Taiti &

Ferrara (1991) also describe a new species Littrorophiloscia stronhali which was

first discovered in Sharjah along with another isopod Somalodillo paeninsulae.

Isopods remain a relatively poorly known group in UAE

S u b - p h y l u m C h e l ic e r a t a

C l a s s A r a c h n id a

Most chelicerate arthropods belong to the class Araclmida and include some of

the most typical arid-zone animals. All araclmids have a pair of feeding organs

called chelicerae, a pair of pedipalps and four pairs of walking legs. The

chelicerae and pedipalps are variously modified according to biology, usuallv

reflecting diet. In structure the chelicerae resemble a pair of pincers with teeth

along their inner edge. The arachnid body is divided into two regions: the

anterior prosoma or céphalothorax and the posterior opithosoma or abdomen.

However, in the Acari and Opliones, the prosoma and opithosoma are not

clearly differentiated. Arachnids are nearly all terrestrial predators of other

arthropods. For further information on Arachnids see Savory (1964 & 1977)

and Cloudsley Thompson (1958),

C h e l ic e r a t a

A r a c h n i d a

S c o r p io n e s ( s c o r p io n s )Almost everybody knows what a scorpion looks like e\en if they have never

actually seen one. The image of their body-shape is ingrained in our minds

from earliest times, and myth and superstition surround them, Manv people

fear and loath scorpions but in common with other venomous animals they

normally avoid humans and w ill only sting when threatened. Most stings

occur when people inadvertently come into contact with scorpions, partic

ularly during camping trips, when they are found hiding under rocks, stones,

tents, clothing, debris and rubbish,

Tlie scorpions are stiucturally a very homologous group and have been highly

successful for over 450 million years. Tliey can be relatively large although some

are only 9mm long. Their bodies are heavily sclerotized with a thick cuticle

forming a compact sliield or carapace over the prosoma, Tliey have one pair of

median eyes and from two to five smaller simple eyes or ocelli, Tlieir chelate-

pedipalps or pincers are massive and powerful and are used to grasp and

manipulate prey. Tliey have four pairs of walking legs, and the basal segments of

the first two pairs are modified for chewing. Tlieir opithosoma is broad and made

up of a seven-segmented pre-abdomen and a five-segmented tail or post-roabdomen with a sting at the tip. On their ventral side is a pair of debate

comb-like organs known as pectines which are thought to be sensory in function.

T l KKIM KI \ i A i\I I IK ’( ir o n s

Scorpions prey on other arthropods,

particularly insects and arachnids but ma\

also feed on small \ertebrates. Scorpions

that ha\ e verv larê pincers do not al\va\>

use their sting to kill prey, but may simpK

relv on the crushing power of their claw s

The chelicerae are used to tear-up the pre\

and digestion actually starts outside the

mouth. They ha\e a long gestation period

and surprisingly are viviparous, meaning

that they give birth to li\e voung Toung

scorpions are smaller versions of their

parents. Maternal care of the \ oung ranyes

trom a few da vs to several months and lan

include complex beha\ iour such a- i n

operative feeding and burrow building.

The lifespan of most scorpions is trom tw o

to fi\e vears but in at least one speaes it

exceeds 23 years! To find out more about

scorpions I thoroughly recommend an exiellent hook edited by Cary P o l i s

(IWO).An interesting phenomenon concerning scorpions is the fact that the\

fluoresce when exposed to ultra violet iL \ i light. \'o-one knows wh\ this

happens; it is |ust a natural propeilv ot the aiticle However, it prov ides an

easy wav ot detecting scorpions and w u -ed Iw biologists to estimate their

numbers w ithout having to capture them It i- a lso an effective wav ot

avoiding scorpions when camping, althougli m -ome desert locations it is

alarming to see iust how many the LA light re' e.,1-'

SCORPIONS IN U A E\'achon (I4SM) li^ts 14 species or s u b - s p e i i e s ol ormon- tiom the Arabian

peninsula. They belong to two families: the huthul.s- .md the Vorpionidae

There are eight genera of buthids: Aiidroiloniiî,

OrlluKluni^, Panil'ullm^ and Vihiioiiioliis, but only two

genera ol scoioionids: Hriin>cor/>iiis and Scorpio. To date only buthids have

Lx'en round m the hmirates. They are .îidrocioiiio^ cni^îciiiido, Ap/t/i(>l’iitliih

/ 1 ,'t'rirgeccrci/-. Hiilliiicih i/eCwtcus/s iuyroiiciiU’iitii>, Coiiio>ohiillnc onilucih^,

Porol'iiiiiii- Tesmi.'.n \\ichomohi> iiiniipcctibiniiC' and possiblv Vihhoiiiolu>

‘pol’inuiiiti^. although it is not clear w hether the latter are two separate species,

or male and female of a single species. There mav well be further scorpions

aw aiting discoverv m live l laiar mountains.

and /\.pli'nipOn'rcii> are the two largest scorpions in UAf:.

\diilts of both species can measure up to l3Hmm from their head to the tip o'

I heir sting and thev can occur near human habitation. They are i]uite different

ill appearame . r.os/,//la/a is black w ith verv cliunkv claws and a highlv

A. crassicauda /s

one ot llic /ifrgi'sf

LIAP ■'lorpioih.

ixa

N a t u r a l E m ir a t e s

1 1 2

sculptured tail, while A.pten/goccrais is pale-yellow with very long, slender

pincers and a swollen disc-shaped second segment on the tail.

The most common species in sandy areas is B.y.iiigwnciilcntiis which is

mostly yellow, but is black on the last segment of tail and sting. Adults can

reach up to about 75mm in length. Tlie Vnclmiolus spp. are slightly smaller and

also yellow with a darker-coloured tip to their sting. The first Vnchouioliis spp

ever collected were from Bada Haza, Abu Dhabi. Both C.ivnbiciis and P.liosoiun

are smaller and only reach about 25mm in length. Tlie former is all vellow,

while the latter is mainly pink, except for the last t%'o segments of the tail and

sting which are brown. I have also found a fragment from the tail of another

scorpion, possibly Ortliocliiriis iniiesi, which is awaiting confirmation.

S c o r p io n v e n o m a n d s t in g s

In recent years there has been much interest in the biology of scorpions, partic

u larly their venom which is a m ixture ot some of the most potent and

biologically active compounds in the animal kingdom. The venom of all buthid

species contains powerful and dangerous neurotoxins. Of the buthids,

Audroctouus nnstralis is considered to be very venomous and symptoms of its

sting resemble strychnine poisoning. Its close relative, A.crnssicnudn. occurs in

the Emirates and should be treated with caution. Victims of stings feel a sharp

pain followed by numbness, drowsiness and an itching of the throat. This can

be accompanied by excessive saliva and the tongue becomes sluggish with the

jaw muscles contracted. If large amounts of venom have entered the blood

system, difficulties in co-ordination arise and body temperature increases

while the production of saliva and urine are reduced. Touch and sight can be

affected, with sensitivity to strong light. Tliere may also be haemorrhages and

convulsions with increasing severity. Most victims are normally out of danger

w ith in three hours but they should receive medical supervision for at least

eight hours.

Primary first aid for scorpion stings is to reassure the victim who w ill be

su ffe ring from shock. Clean the wound and then try to isolate it by

immobilising the sight of the sting. Use a firm supporting bandage but not a

tourniquet, and hold the limb up to avoid the venom going directly to the

heart. If possible keep the site of the sting cold by placing it in iced water.

Although fatalities are \'ery rare, do seek medical help, particularly in the case

of small children and invalids who are most at risk. In some cases, an anti

venom can be administered and these work well if given early enough.

However, in other cases a pain killer is all that can be given but recovery

should be rapid.


A r a c h n i d a

P s e u d o s c o r p io n e s (p s e u d o s c o r p io n s )Pseudoscorpions are similar in structure to scorpions although they lack the

post abdomen and sting. They are distinguished by their minute size and only

measure between 1 and 7mm long. Their bodies are flattened in appearance

and some species lack eyes. Their palpal chelae or claws are large, like those of

scorpions, with a swollen "hand" and a moveable finger or digit. They use

their chelae to climb up hairs of other animals. Although they normally walk

forwards, they are equally good at going backwards. Sometimes they are

gregarious and found in large groups.

Pseudoscorpions are predators and possess a poison gland at the base of

their pincers which they use to anaesthetise prey. They feed on other tiny

arthropods such as spring-tails (Collembola), book-lice (Psocidae), mites

(Acari) and silverfish (Thysanurana). Food is digested externally by a fluid

poured over the prey and the liquefied remains are ingested by the chelicerae.

Pseudoscorpions regularly clean their palps to remove remains of food so that

they can easily suck up their next meal through special grooves.

Some pseudoscorpions are phoretic which means that they use other

animals for transport and dispersal over larger distances. They do so by

attaching themselves to the legs of insects (such as flies) using their pincers.

Others live under the elytra of large beetles where they prey upon parasitic or

phoretic mites also living on the beetles. They have even been seen h e ck lin g

to beetles which then let them mount their bodies!

T (‘r k f s t r ia i A r t h r o p o d s

Despite their minute size pseudoscorpions demonstrate a tremendous

variety and complexity of lifestyle. They have silk glands and construct nests

of silk for moulting, brooding and hibernation. Tlieir courtship dances may be

very complicated. Females carry their eggs in a brood sac attached to their

genitalia and actually provide nourishment in the form of a nutritive fluid

which passes to the embryos in the brood sac. Some species exhibit parental

care with the young riding on the back of females, but thev generallv disperse

very quickly. The young are identical to adults in all but size and undergo

three moults before they are fully grown. For further information on these

minute but fascinating animals see Weygoldt (1969) and Legg & |ones (1988).

P s e u d o s c o r p io n s in UAEAlthough pseudoscorpions are generally associated with moist habitats such as

leaf litter and crevices, the families Olipiidae and Cheliceridae prefer dry

habitats and may well occur in UAE. Manhert (1980) identified se\ en species of

pseudoscorpions from the Arabian peninsula, tour of them new to science and

Manhert (1991) found 12 species from Oman alone. So tar only two uniden

tified specimens have been found in UAE. Thev were both inside a light trap

and had probablv been using a fly or large beetle tor transport


A r a c h n i d a

S o L iF U G iD A (S o l if u g id s o r c a m e l s p id e r s )

Solifugids have four pairs of long, hairy legs and enormous, well-de\eloped

jaws. They appear to ha\ e a large "head" which can be as long as the rest of

the prosoma and houses the powerful muscles needed to operate the

chelicerae. The teeth on the chelicerae consist of solid chitin (an exfremeb

strong protein) and a solifugid bite can be severe. The chelicerae are co\ ered

with numerous spines and setae which help to remo\ e solid pre\ so that the\

can ingest their liquid diet. Males are usuallv smaller than females and in some

species, their teeth are reduced to a ridge pre\ enting efficient feeding and the\

do not live long

Camel spiders are one of the fastest running arthropods. Although thev

have four pairs of legs, they run using only three pairs. The first pair of legs or

pedipalpi are held up in front of them and used in a similar manner to the

antennae of insects. Thev have very long, silky setae and are constantly

moving in order to locate and pick-up prey. On the underside of the last pair of

legs are five malleoli or racquet organs which are thought to be sensory in

nature and function like the pectines of scorpions. They use their second pair

of limbs as rakes to push loose soil when constructing burrows and move the

soil in rapid mox ements, looking like little bulldozers'

Despite their fearsome appearance and their strong bite, solifugids are

unlikely to harm humans. In the past they were considered venomous and

extremely dangerous but it is now thought that the only risk of injury resulting

from them is caused by shock or infection follow ing a bite. There is no

evidence of venom m any part of their body.

Camel spiders are nocturnal predators of other arthropods including

scorpions and are \ oracious teeders. Some species kill and feed on lizards and

it is speculated that others kill mice and birds. They rely solely on their speed

and stealth to catch their prey. In desert areas they are often attracted to lights

Civiicl spiders iirc

ciillcd solifiiyids.

bcciiiisc tlici/ nvoid

('ciiiy out III Ilk' >1111.

It onciiL'cidciitnlli!

UIICOVCIS II Lllllll'l

>pidcr, it will

friiiiticnlhi look for

■blinde, u>iinlhi found nt

oiicd foot Tins clinriK-

tcri>iic lins y i i ’iTi it on

tiiidc>i'ivcd ropiitnlioiiK>

eUiygressieii w

Camel spider,

Solifugid galeodes.

1 1 4

at night in search of food and their appearance can cause alarm if they enter

tents. It IS rare to see them during the winter months in UAE and they are

thought to hide or hibernate during cold periods.

Females dig a burrow in which they lay over 200 eggs. They guard then-

young for two to three weeks until the first moult. Although they are quite

large, solifugids are thought to live for less than one year.

C a m e l s p id e rs in UAEDespite their conspicuous appearance and size, little is known about these

creatures and we are not e\ en sure of their exact identity. There are probably

three families of solifugids in UAE. These are the long-legged and sandy-

coloured Galeodidae and Solpugidae, and the black-coloured Rhagodidae

which has shorter legs and is better adapted for digging. The Galeodidae are

commonly seen in sandy areas and the largest species is probablv Galeodes

arabs which is particularly hairy and bulky with limbs spanning up to l^Omm

Other species probablv occur in the mountains and Rhagodidae are thought to

occur around .Al Ain

C h e l ic e r a t e s

A r a c h n i d a

S c h i z o p e l t i d a , T h e l y p h o n i d a a n d A m b l y p y g i

( w h ip s c o r p io n s a n d t a il - le s s w h ip s c o r p io n s )These obscure arachnids are very poorly-known and superticiallv resemble

scorpions but lack a sting. However, the whip scorpions, Schizopeltida and

Thelyphonida, have slender, whip-like appendages or tails and exhibit a

defensive reaction, by discharging a caustic, dust-like cloud trom an anal

gland, which smells strongly of acetic acid or chlorine gas. Schizopeltida are

similar in habits to scorpions but are only 5-7mm long. They are nocturnal and

hide under stones or in burrows during the day. Thelyphonida are relatively

large, nocturnal predators feeding on a wide variety of arthropods. They are

quite ferocious in appearance and although their chelicerae arc not claw-like

their pedipalps are very powerful. The Amblypygi can be relatively large (8-45

mm in length) and are flattened in appearance. They lack a tail and are

sometimes called tail-less whip scorpions. They are also nocturnal predators

and have raptorial pedipalps armed with strong spines and a moveable hook

with which they grab their prey.

There are no known records of these arachnids in UAE but Schizopeltida are

common m other arid regions and may have been over-looked. Thelyphonida

and Amblypygi are generally found in the tropics and could occur in moister

en\'ironments such as wadis.


A r a c h n i d a

O p il io n e s ( h a r v e s t m e n )

Opiliones or harvestmen are cosmopolitan predators inhabiting a wide range

of habitats. They superficially resemble spiders but their legs are very long and

spindlv and the prosoma is not divided from the opithosoma. They teed on

dead nr recently dead tissues and probably require a humid environment.

Ehey have not been recorded from UAE, but probably occur in t l^ more

humid areas.


A r a c h n i d a

A r a n a e a

Aranaea are the true spiders and arid-zone species tend to be cryptically

coloured, often with brushes of hair on their undersides to help them move

through sand. Spider chelicerae are hook-like with moveable digits that carry

poison glands, but most are harmless because their chelicerae are too weak to

pierce human skin. They are predators and are further classified into separate

families according to their anatomy and biology which reflect the way in

which they capture their prey. For example, some spm webs and sit and wait

for their prey while others are active hunters. Spiders are found world-wide

and occur is all types of habitats.

S p id e rs in UAEAt present little is known about spiders m the Emirates but current investi

gations by the American Museum of Natural History w ill soon tell us more.

However, the spider fauna of the Sahara region is known, and includes a wide

range of spider families such as ground hunting spiders (Giwtliosidni’), crab

spiders (Thomisiiiae), giant crab spiders (Spnrnssiiine), bark spiders {Hcrsiliulne),

jumping spiders (Salticidae), wolf spiders {Uicosidae), sheet-web spiders

{A^ekuidae), comb-footed spiders (Tlieridiidiu'} and orb-weavers {Tetrn^uatliuini

and Ar^wpidiie). All these families probablv also occur in the Emirates

Spiders of the Arabian peninsula as a whole are not well studied. Twenty-

nine species of Salticidae have been found, many of which were undescribed

but resembled African or Asian spiders (PrÛszynski,1993). Eight species from

S I X genera of crab spiders or Thomisidae also occur (Dippenaar-

Schoeman,1989). One of these, Thouiisiis dtnnelliis, has a wide distribution and

probably inhabits UAE. In Saudi Arabia, two species of Linyphiidae have been

recorded although they are not normally considered arid-zone species

(]ocquE,1981).

B l a c k w id o w s ( T h e r i d i i d a e ; L a c t r o d e c t u s s p p )

Two species of black widow are common in the Middle East, Lactrodectus

pallidiis, occurring from Libya to Azerbaidjan, and Lactrodectus Injsterix, known

from Aden and Yemen. In the Emirates, black widows occur along the coastal

strip and hide in rubbish or objects left outside overnight. Care should

therefore be taken when picking up debris etc. Their bite is rarely felt but is

noticed later when the wound starts to swell and two tiny spots become visible

where the fangs have penetrated the skin. The bite is very painful and the

whole body can ache especially the legs. Other symptoms include shock, fever,

nausea, headache, raised blood pressure, difficulty in breathing and heavy

sweating. However most bite victim s

recover completely w ith in two

days. If bitten seek medical

attention and always reassure

the v ictim . Treatment

includes intravenous

salts and pain

kille rs which

alleviate

symptoms

The crab spider,

camouflaged by its

colour, waits at the

heart of a floioer, to

catch Its prey.

Natural Emirates

The velvet mite oiihf

nppeni'S nbove pinmmi

after rams.

1 1 6


A r a c h n i d a

A c a r in a o r A c a r i ( M it e s a n d t ic k s )The Acari are the smallest chelicerates hut are also the most numerous world

wide in terms of the number ot species. Thev are commonly known as mites

and ticks. Adults have four pairs of legs while the voung have three pairs

Thev include both parasites and predators which generallv live on other

animals or inside plants, although some inhabit the soil. Seven orders of Acari

are recognised: Notostigmata, Tetrastigmata, .Mesostigmata, Metastigmata.

Cryptostigmata, Astigmata and Prostigmata.

The Notostigmata and Tetrastigmata are predatory mites frequenting

warmer regions ot the world, and probablv live in the Emirates. The other

orders are cosmopolitan and probably occur, but are relatively unknown

because of their small size. However, the Metastigmata nr ticks arc better

known because thev are ectoparasites of terrestrial vertebrates and some are

important pests of livestock and vectors of disease. Crvptostigmata are verv

small and dark in colour and live in soil and leaf litter where thev feed on dead

and decaying plant material. Astigmata are small and generallv feed on fungiw

or detritus, but thev also include some parasites of vertebrates known as fur

and feather mites. Prostigmata are more heterogeneous and include tree-living

predators, phytophagous mites, parasites and aquatic mites.

Ticks are divided into two types: the hard ticks or Ixodidae and the soft ticks

or Argasidae. Ixodids have a hardened dorsal scutelum which is absent in

argasids. Argasids are most abundant in dry regions. The family Argasidae

contains two genera: Ar^as which are associated with birds, bats or their

nesting/resting places, and Oniitliodorus which frequent burrows, corrals or

houses. The larger Ixodidae fam ily comprises six genera: Hualomma.

Amblpomma, Rliicicephalus, Boopliihis, Apoiwmma and Haemapbpsalh

Tick bites can be painful and irritating, and severe cases ot multiple tick

infestation in a single animal, can result in anaemia, toxic reaction and

paralysis. However, it is the tick's potential as a vector ot pathogenic disea-^c"

that is more .seriou.- . Although man is onlv an incidental host and their natuia'

hosts are wild animals,

some of the tick species

present in Arabia can

t r a n s m 1 1 h u m a n

d i s e a s e s . M a n \

po ten tia lly infected

ticks are accidentally

im ported along w ith

foreign livestock but

are equally able to feed

on local livestock and

c o u l d e s t a b l i s h

permanent populations.

If thev are infected with agents pathogenic to humans or domestic animaH

these may also be spread by local ticks. Although cases ot tick-borne human

disease are rare there is an element of risk.

T ic k s f r o m U A E

There are no published records of ticks for the Emirates but the following

species are native to Arabia (Hoogstraal et al, 1984) and therefore likelv to be

part of the local tick fauna. Hi/alomma In/alomma aiiatolicitm aiiatoliciim is verv

common and its hosts include domestic stock, lizards, rodents, hedgehogs,

hares and humans. It is the ma)or vector of Crimean-Congo Haemorrhagic

Eever (CCHF) in the Southern Soviet republics, Pakistan and Nigeria. Othei

common Hvalomma ticks include H.li.ilromedani which is both a vector tor

CCHE and a natural reservoir of Q-tever; and H.li.impeltatiim and

H.li.mar<^iiiatiim turcanicum which have also been implicated as vectors tor

CCHF The kennel or brown dog tick, Rliipicephalus rliipicephaius siutytimciis,

generallv feeds on dogs as its name suggests, but can carry CCHF as can the

closely related R.r.tiiranicus. Another vector of CCHF is Roophilus aimiilatus

although its preferred hosts are goats. Human cases of CCHF are verv^re in

the Emirates, but it has been reported from Dubai.

O t h e r m ite s in UAEProbablv the largest mite in UAE is the giant velvet mite,

Diiwntlironibiiiiti sp. Adult mites measure up to 12mm and are covered in a

thick and dense scarlet tur which warns predators that they are distasteful.

Adults onlv emerge after heavy rain when thev wander around sandy areas m

search of termites. I have found them on se\ eral occasions near Sweihan and

Al Samha. Their larvae are parasitic on grasshoppers.

Oribatid mites are one of the richest soil arthropod groups both in terms of

numbers and species diversity. Bavoumi & Al-Khalifa (1985) report 48 species

from Saudi Arabia but thought that the number of species was limited bv soil

humidity.

I n s e c t a - M y r ia p o d a

The Insecta-mvnapoda are the most niimericallv important group of animals

in the UAE. As well as the insects this group includes millipedes (Diplopoda),

centipedes (Chilopoda or Scolopendrida), and the lesser known Pauropoda

and Symphyla. The name Myriapoda reflects the fact that these animals have

manv legs and, as w ill be seen, they are a di\ erse group.


D ip l o p o d a

The diplopoda are commonly known as millipedes. Their body is made up ot a

large number of double-sided segments each bearing two pairs of legs. Thev

are slow moving detriti\ ores and are usuallv found in leaf litter and rotting

vegetation. Millipedes are most abundant in the tropics and have not been

recorded from UAE but probabh' occur m relativeh' humid areas such a

wadis, parks and gardens.


C h il o p o d a o r S c o l o p e n d r id a

( C e n t ip e d e s )

There are three fam ilies of centipedes; Ceophilom orpha,

Scutigeromorpha and Scolopendromorpha. However, only the latter occur in

the Emirate^, Scolopendrid centipedes have an elongated, dorso-ventrallv

flattened hod\ w ith a distinct head. The head bears a single pair of antennae

and three pairs ot feeding appendages (a mandible and two pairs of maxillae).

The trunk can ha\ e trom 15 to over 10Ü segments each bearing a single pair of

legs which results in their characteristic locomotion, and centipedes can measure

up to 12ilmm m length The first pair ot trunk appendages is known as the

maxillipedes or toxognatha and has powerful terminal claws at the tips, which

have ducts leading to poison glands. Centipedes cannot usuallv pierce human

skin and are unlikely to be poisonous but it is best to treat them with respect

The\ are generallv nocturnal predators and feed on other smaller

arthropods. During the day thev hide under rocks, stones and debris. Female

Scolopendrids care tor their voung bv making a protective basket between the

body and legs, formed bv curling their legs around the voung.

C e n t ip e d e s in UAELewis & Callagher (1993) mention \ arious records of scolopendrids tor U.AE

although the\ probablv occur in most areas. Scolopciidiidn iiiinibilis has been

found in Masah, Sharjah and jebel Faivah while Scolopciidiidn volidn was collected

near Sharjah. Both species are thought to be very resistant to desiccation.

C e n t ip e d e b it e s

The medical importance ot centipedes was probabh oxerestimated in the past

since onh \er\ old records mention human fatalities (Lewis, 1986). However,

the bite nt S lunnhili^ is though to be like that ot a s im ila r genuso

17

N atu r a l Em irates

Many interesting Tmchycormocephahts which causes pain, swelling and

spiders remain as yet subcutaneous bleeding. The area around the bite is

unidentified. particularly tender but most symptoms disappear

within 24 hours. First aid treatment for a centipede bite

is similar to that for scorpion stings although it is less

likely to be life threatening


P a u r o p o d a a n d S y m p h y l a

These two groups of myriapods are less common fhan

the others. They are both multiple-limbed, small and

soft-bodied. They live m soil and leaf litter where they

are thought to feed on fungi and detritus, although the

Symphyla also feed on living plant material. Little is

known of their biology and distribution and they have

not been reported from UAE, but they could occur in

the soil fauna of moderafely moist environments.

118


S u b - p h y l u m o r c l a s s T a r d ig r a d a

I could not finish this chapter without mentioning the tardigrades. These

minute animals only measure 50-500pm in size and cannot be seen without the

aid of magnification. They have six legs ending in claws and are commonly

known as water bears because of their rotund appearance. They live in the

siuface film of water covering mosses and in fresh and salt water. Since they

can withstand prolonged periods of desiccation they could easily occur in

temporal rain pools or beaches in UAE. To my knowledge, there is no

published research work on the desert tardigrades but they would be an

interesting subject for study.

Arthropods are very successful and many are able to flourish m the dry

climate of the UAE either through adaptation to their environment or by

behavioural avoidance of extreme conditions. They include a few defritivores

and herbivores, but are predominantly predators. However they are all

potential prey for vertebrates such as birds, mammals and reptiles. The larger

species, such as scorpions and camel spiders, are particularly good sources of

food for fhose able to catch them. However, there sHll remains much that we

do not know about them, including which species actually occur in the

Emirates. There are probably numerous new records and species waiting to be

discovered all over Arabia. Next time you come across an arthropod be content

to watch and admire it for its powers of survival.

A c k n o w l e d g e m e n t s

I thank Dr john Balfour for information on public health pests. Dr Vojin Sjlivic

for discussions about scorpions stings and Dr Patrick Osborne for commuting

on an earlier draff of the text.

R e f e r e n c e s

Hoogstraal, H., Wassef, H. Y. & Buftiker, W. (1984). Ticks (Acarina) of Saudi Arabia.

Family Argasidae. Ixodidae' F n iii in o fS n iid i A rn h in , 3. 23-110

Barnes, R.D. (1987). I in ' t r h ' l ’n i t i ' Z o o h j^ /. Fifth edition. Saunders College,/Holt, Rhinehart

and Wilson, USA.

Bayoumi, B. M. & Al-Klialifa, M. S. (1985).' Oribatid mites (.Acari) of Saudi Arabia'. F n iiiw

o f S aud i A rn b in , 7,66-92.

Cloudsley Thompson, J. L. (1958). Spiders, scorp ions, ic n fip e d rs an d m iles. Pergamon Press,

London.

D ippenaar-Schoeman, A. S. (1989). 'A n annotated check lis t ot Crab Spiders

(Araneae:Thomisidae) of Saudi Arabia'. Fauna of Saudi A ra b ia ,1 0 ,20-30

Ferrara, F. & Taiti, S. (1985). 'The terrestrial isopods (Oniscoidea) of the Arabian

Peninsula'. Fauna o f S aud i A ra b ia , 7 , 93-121

Polls, G. A. (ed.) (1990). The b io logy o f scorp ions. Stanford University' Press, USA.

JocquE, R. (1981) 'Araneae:Fam. Linyphiidae'. Fauna o f S aud i A ra b ia . 3,111-113.

Legg, G. & Jones, R. E. (1988). 'Pseudoscorpions'. S pnops is o f the B r it is h F auna (New

Series) Kemack, D. M. & Barnes, R. S. K. (eds.) No. 40. W BackJnivs, Leiden,

Lewis, j. G, E.(1986). 'Chilopoda ot Saudi .Arabia: centipedes of Saudi Arabia'. Fauna ot

S aud i A ra b ia , 8, 20-30

Lewis, j. G. E. & Gallagher, ,V1. D. (1993). 'Scolopendromrph and Geophilomorph

centipedes trom Oman and UAE'. Fauna o f S aud i A ra b ia , 13, 55-62.

Manhert, V. (1980). 'Arachnids of Saudi Arabia: Pseudoscorpiones'. Fauna o f Saudi A rab ia ,

1,32-48.

Manhert, V. (1991). 'Arachnids of Saudi Arabia. Pseudoscorpions (Arachnida) from the

Arabian Peninsula'. Fauna o f S aud i A ra b ia , 12,171-199

Manton, S. M. (1977). The A r th ro p o d a - h a b its , fu n c t io n a l m o rp h o lo g y a n d e v o lu t io n

Clarenden Press, Oxford.

Meglitsch, P. A. (1967). In ve rte b ra te zoology. Oxford University Press, Oxford.

PrÛszynski,]. (1993). 'Arachnids of Saudi Arabia: Salticidae (Araneae) of Saudi Arabia II'

Fauna o f S aud i A ra b ia , 13 ,27-54.

Savory, T. H. (1964). A ra ch n id a . Academic press, London.

Savory, T. H. (1977). S p id e rs a n d o th e r a ra ch n id s The English Universities Press Ltd,

London.

Sheals, J. G. (1973). 'Arachnida'. In: Smith, K. G. V. (Edi Insects an d o th e r a rth ro pods ot

m ed ica l im p o rta n c e , pp 417-472. Trustees of the British Museum (Natural History),

London

• %

- - ' J '

%

- V

■ . , 4. ^■* ■ ( A

Sheals, j. G. (1973). 'Other Arthropods' In: Smith, K. G. V. (Ed) Insects a n d o th e r a rth ro pods

o f m e d ica l im p o rta n c e , 473-482. Trustees of the British Museum (Natural History),

London

Taiti, S. & Ferrara, F, (1989). Terrestrial isopods of Saudi Arabia (Part 2)'. Fauna o f S aud i

A rab ia , 10, 78-86.

Taiti, S. & Ferrara, F (1991). '.New species and records of terrestrial isopods (Crustacea)

trom the Arabian Peninsula' F auna o f S aud i A ra b ia , 12,209-224.

\achon, VI. ( 1989) Arachnids of Saudi Arabia. Scorpions'. Fauna o f S aud i A ra b ia , 1, 30-65

IVevgoldt, P (1969). The biolosiu ot iise iidosco rp io iis . Harvard University Press, Harvard.119

243

Class Order (Division) Family(subfamily)

Genus & Species (if known) Methodof

capture

Verifiedby

Arachnida Scorpiones Buthidae *Androctonus crassicauda (Olivier) p JB

Arachnida *Aplstobuthus pterygocercus Finnegan p JB

Buthacus yotvatensis nigroaculeatus p JB

Levy et al.Compsobuthus arabicus Levy et al. p JB

Parabuthus liosoma (H. & E.) p JB

*Vachonioius minipectinibus (Levy et p JB

al.)Vachonlolus globlmanus Vachon p JB

*Nr Odhochlrus InnesI Simon F BJT

Solifugae *Ga!eodes arabs Koch P, H PH

*Galeodes? spA. P PH

indet. (not Galeodes) P PH

Araneae Gnaphosidae *Pterotrlcha sp A. P LS

Araneae Gnaphosidae *Pterotrlcha sp B. P LS

*Lachesana sp P LS

Lycosidae indet. P PH.LS

Salticidae indet. P PH.LS

Theridiidae indet. P PH, LS

Philodromidae indet. P PH.LS

Sparassidae indet. H PH

Eresidae *Stegodyptus llneatus P PH

Acarina Ixodidae Hyalomma sp. P JB

Caeculidae indet. P AB

Trombidiidae DInothromblum sp. H AB. BJT

Entognatha Colembolla Arthropleona indet. P BJT

Insecta Thysanura Lepismatidae Nr Thermobla domestica Packard P JB

indet. P JB

Odonata Aeshnidae Hemlanax ephlpplger Burmeister L JB

Orthoptera Gryllotalpidae Gryllotalpa africana Pal. L JB

Gryllidae Acheta domestica Linnaeus H JB

Indet. P JB

Pyrogomorphidae Pyrgomorpha indet. L GP

Pyrgomorpha conica- bisplnosa gp. L GP

Chrotogonus homalodemus H GP

(Blanchard)Tenultarsus angustus (Blanchard) H GP

Acrididae Derlcorys cyrtostema Uvarov L GP

Acorypha glaucopsis (Walker) L GP

Heteraciis annulosa (Walker) L GP

Heteraciis llttoralls Rambur L GP

*Hyalorrhlpls canescens (Saussure) H GP

Sphlngonotus rubescens (Walker) H GP

Acrotylus longlpes (Charpentier) H GP

Truxalls procera Klug H GP

*Ochrllldla tibialis (Fieber) H GP

Ochrllldia genlculata (Bolivar) L GP

*OchrlHdla persica Salfi L GP

*Leptoptemls gracilis (Eversmann) H GP

"Tridactylus fasclatus Guerin L GP

Tettigoniidae Nr Platyclels sp. nymph P GP

*Conocephalus concolor (Burmeister) L GP

*Ruspolla nitldula (Scopoli) H GP

*Dlogena fausta Burm L GP

Dermaptera Labiduridae *Labldura ripaiia (Pallas) L JB

Mantodea Eremiaphilidae *Eremlaphlla gene Febv. P JB

Mantidae *Blepharopsls mendica Fab. H JB

*Rlvetlna Inermis Uvar. H JB

*Mlcrothespls dmltiiewl VJern. L JB

Ins pitched Kalt H JB

*Hypslcorypha gracilis Burm. H JB

Appendix 4.1 List of species caught in UAE (1992-1996).

244



capture

Verifiedby

Insecta Mantodea Mantidae *Sinaiella sabulosa Uvarov L JB

Mantodea Mantidae *Sinaiella nebulosa Uvarov L JB

Isoptera Rhinotermitidae Psammotermes hybostoma Desneaux P JB

Indet. Indet. P JB

Phasmatodea Phasmatidae *Ramulus sp. H JB

Hemiptera(Homoptera) Fulgoridae Indet. P MW

Dictyopharidae Indet. P MW

Cicadidae Platypleura arabica Myers H, L BJT

Aphididae Indet. H JB

Hemiptera(Heteroptera) Tingidae *Phaenotropis Cleopatra (Horvith) L GS

Reduviidae *Reduvius sp. P GS

*Putoniola sp. P JB

Miridae *Eurysty!us bellevoyei (Reuter) H GS

Indet. H GS

Lygaeidae Indet. L GS

Coreidae *Homoeocerus varlabills (Dallas) P GS

Cydnidae *Amaurocoris aspericollis Puton P GS

Dinidoridae Cordius viduatus Fabricius H, L BJT

Pentatomidae *Chorantha ornatula (H-S) L GS

*Bagrada sp. P GS

Neuroptera Myrmelionidae *Tomatarella markii Kimmins L JB

*Paipares cephalotes Klug L JB

*Neuroleon parvus Kimmins L JB

*Neuroleon nr nemausiensis Bork. L JB

*Myrmeceiaurus nr caudatus Navas L JB

*Gepus invisus Navas L JB

*Nr Cueta sp. L JB

Lepidoptera Sphingidae Agrius convolvuli Linnaeus H BJT

Acherontia styx Westwood H BJT

Macroglossum stellarum Linnaeus H BJT

Daphnis netil Linnaeus H BJT

*Hyles llvomica Esper L BJT

HIppotlon celeiio Linnaeus L BJT

Noctuidae *Agrotls biconica Koilar L JB, EBW

*Hellcoverpa nublgera (H.-S) L JB

*Amlcta munna Kiug H, L EBW

*Anumeta eberti zaza Wiitshire L EBW

*Anumeta spllota Wiltshire L EBW

*Cerocala sana Staudinger & Rebei L JB

Lasiocampidae *Chrondrostega fasclana felsall L EBW

WiitshireStreblote sIva Lefèbvre BJT

*Lambessa decolorata L EBW

Cossidae "Lamellocossus arias Pungeler L JB

*Lameiiocossus cheesman/Tams L JB

Pyralidae *Hercynodes afflnis Rothschiid L JB

*Epizonara confusalls Hampson L JB

"Epizonara sinaica Rebei H MS

Microlepidoptera Indet. P JB

Diptera Therevidae indet. L JO

Tephritidae *Gonlurellla tridens (Hendei) H IW

Asilidae *Apociea femoralls Weidemann H NW

Bombyliidae Anthrax sp. H NW

*Heteropus sp. H JO

Ephyridae *Ephydra sp. H NW

Sarcophagidae *Blaesoxlpha sp. H NW

Galliphoridae *Vlllenuevlella sp. H NW

Sphaerocideridae Indet. L JB

Appendix 4.1 Continued List of species caught in UAE (1992-1996).

245



capture

Verifiedby

Insecta Diptera Sphaerocideridae nr Telomerina sp. L NW

Muscidae Musca domestica Linnaeus M. L BJT

Heliomyzidae *Trichoscei!s sp H NW

Ceratoponogidae Cullcoides mesghalil Naval H JB

Hymenoptera Bethylidae Indet. L AW

Braconidae, Indet L JB

RogadinaeScoliidae *Campsomeneiia thoracica Fabricius H

Tiphiidae Indet. L JB

Hymenoptera Mutillidae Indet. sp1 P AW

Indet. sp2 P JB

Indet. sp3 P JB

Braenidae Indet. P

Bradynobaenidae *Pterogyna savigni Klug P JB

Indet. P JB

Formicidae(Ponerinae) *Pachycondy!a sennaarensis (Mayr) H.B CAC

(Myrmicinae) *Cardiocondyia emery! Forel H,B CAC. DA

*Cardlocondyla gallagheri Collingwood H.B CAC

& Agosti*Cardiocondyla stiuckardi Forel H .P CAC. DA

*Crematogaster aegyptiaca Mayr P CAC

Crematogaster antaris Forel P CAC

*Crematogaster mosis Emery P CAC

*Leptothorax //V/ae Collingwood & P.H CAC. DA

AgostiMessor ebeninus Santschi P CAC

*Messor forel! Santschi P CAC

*Messor h/sma/Collingwood & Agosti P CAC

*Messor mendionaHs (André) P CAC

*Messor muscatus Collingwood & P CAC

AgostiMessor rufotestaceus (Foerester) P CAC

Monomorium abeille! André P CAC

*Monomorium arenlphllum Santschi P CAC

*Monomorlum barbatulum Mayr P CAC

*Monomorlum buxtoni Crawley H,B CAC

*Monomorlum chobauti Emery P CAC

*Monomorium destructor (Jerdon) H CAC

*Monomoiium fezzanense Co\\\ri^ood P CAC

& Agosti*Monomorlum gallagheri Collingwood & P CAC

Agosti*Monomorlum Indlcum Forel H CAC

*Monomorlum mayr! Forel P CAC

*Monomorlum m/ntmbe Collingwood & P CAC

Agosti*Monomor!um nllotlcum Emery H CAC

*Monomorium tumaire CoWmgwood &. P CAC

Agosti*Monomorlum wahlblense CoW'mgwood P CAC

& Agosti* Pheldole megacephala (Fabricius) H.B CAC

*Pheldole sculpturata Mayr H.B CAC

*Pheldole tenerlffana Forel H.B CAC

*Solenopsls gemlnata (Fabricius) H CAC

*Tertramoiium blcaiinatum (Nylander) H CAC.DA

*Tertramorium calldum Forel H.B CAC

*Tetramoiium juba Collingwood H.P CAC

(Dolichoderinae) *lrldomrmex anceps (Roger) H.B CAC

*Leneplthema humlle (Mayr) H.B CAC.DA

*Taplnoma simrothi Krausse H.B CAC.DA

*Taplnoma megacephalum (Fabricius) H .B CAC.DA

Appendix 4.1 Continued List of species in UAE (1992-1996).

246


Genus & Species (if known) Method Verified of by

capture

Insecta Hymenoptera

Coleoptera

PompilidaeVespidaeSphecidaeSphecidaeApidaeCarabidae

StaphilinidaeCicindelidae

DytiscidaeNitulidaeMeloidaeCoccinelidae

Curculionidae

(Formicinae) 'Camponotus compressus (Fabricius)*Camponotus fellah Dalla Torre

*Camponotus oasium Forel 'Camponotus sehceus (Fabricius) Camponotus thoraclcus Fabricius

Camponotus xerxes Forel *Cataglyphis acutinodis Collingwood & Agosti*Cataglyphls adenensis (Forel) 'Cataglyphis albicans (Roger) "Cataglyphls arenarius Finzi *Cataglyphls cinnamomeus Karawaiew

*Cataglyphis flavobrunneus Collingwood & Agosti Cataglyphis lividus (André)Cataglyphis minimus Collingwood Cataglyphis niger (André)Cataglyphis sabulosus Kugler

"Cataglyphis urens Collingwood

"Cataglyphis viaticus (Fabricius) "Lepisiota gracillicornis (Forel) "Lepisiota nigrescens Karawaiew

"Lepisiota opaciventris (Finzi) "Lepisiota spinisquama (Kunetsov- Ugamsky)"Paratrechina flavipes (Smith) "Paratrechina jaegerskioeldi (M ayr) "Paratrechina longicornis (Latreille) "Polyrhachis lactipennis F. Smith

Indet."Vespa orientalis Linnaeus

Bembix sp Indet.."Pseudapsis n Hot ica Smith Thermophilum (=Anthia) duodecimguttata Bonelli "Scarites guneensis Dejean

"nr Harpalus spl "nr Harpalus sp2

Indet."Salpingophora nr ruppelli (G -M ) "Lophyridia aulica Dej."Eretes sticticus Linnaeus

Indet.Indet.Coccinella septempunctata Linnaeus "Hyperaspis vinciguerrae Capra

"Elasmobarls nr alboguttata (Brisoutj "Lixus (Phillixus) sp."Ocladlus sp."Bothynoderes anxius (Gyllembal) "Ammocleonus aschabadensis Faust "Gronops nr pallidulus "Bagous cyperorum Bagoussp.*Nr Xylinophorus sp.*Nr Pseudostytyphlus sp.

(Entiminae) indet. Tanymeclnl

Chrysomelidae "Pseudocolaspls sp."Macrocoma leprieuri Lefevr.

p

p

p

p

p

p

p

p

p

P, H

p

P, H

p

p

H

P, H

P. H

HH.B

P, H

H.B

H,B

H.B

H,B

H.B

H,B

L

H

ML

L

P

P

P

P

P

H

H

L

P

P

H

H

P

L

P

H

H

P

P

P

P

P

P

H

H

CAC.DA

CAC

CAC

CAC

CAC

CAC

CAC, DA

CAC

CAC, DA

CAC

CAC, DA

CAC, DA

CAC, DA

CAC, DA

CAC, DA

CAC, DA

CAC, DA

CAC, DA

CAC

CAC

CAC

CAC

CAC

CAC

CAC

CAC

JB

BJT

AW

JB

JB

JB

JB

JB

JB

JB

JB

JB

JB

JB

JB

BJT

JB

RT

AT

AT

AT

AT

AT

AT

AT

AT

AT

AT

SS

ss

Appendix 4.1 Continued List of species caught in UAE (1992-1996).

247


Genus & Species (if known) M ethodof

cap ture

Verifiedby

Insecta Coleoptera Elateridae *nr Heteroderes sp. L JB

Histeridae *nr Saprinus chalcites ill. P JB

Tenebrionididae *Prochoma nrclypealis Blair P JB

*Prochoma bucculenta Koch P JF

*Microtelus nejdanus Kaszab P JF

*Ammogiton sonyae Kaszab P JF

*Nr Falsocatomulus sp. P JF

*Foleya brevicomis Peyerimhoff P JF

Pimelia arabica Klug P JB.JF

*Pimella arabica s.sp.? P JB

*Pimelia arabica edomita Kaszab P JF

*Pimeiia ionguia Kweiton P JF

*Parapiatyope popovi Koch P JB, JF

*Biaps koiiari Seidlitz P JB. JF

*Adesmia khaiiensis Blair P JB

Adesmia stoekieini Koch P JB

*Adesmia arabica Reitt P JB

* Adesmia persiana Reitt P JB

*Tentyrina paimeri (Crotch) P JB, JF

*Sceiosodis besnardi P JB

*Arthrodibius cicatrix P JB

*Zophosis migneauxi Deyr. H JB

*Cyphostethe nr saharensis Chob. M JB

*Phaeotribon/Pachycera P JB

*Prochoma sp. P JB

*Phaeotribon puicheiium P JB

*Gonacephaium rusticum (Olivier) P JF

*Gonacephaium setuiosum P JF

(Falderm ann)*Anemia sardona (G ene) P JB, 88

*Apentanodes sp1 P JB

Mesostena puncticoiiis Sol. P JB, JF

*Oxycara breviuscuium Fairm. P JB

*Trichosphaena arabica Kaszab H JB

*Nr Phaeotribon P JB

Pachycera pygmaea arabica Kaszab P JF

Pachycera sp P JB

*Erodius reichei Allard P JB.JF

*Erodius nr octocostatus Peyerimhoff P JB

*Erodius sauditus Kaszab P JB, JF

*Arthrodibius cicatrix (Fairm ) P JB

Trachyderma(=Ocnera) phiiistina P JB

Reiche*Trachyderma striatogranosa P JF

(Fairm aire)*Apentanodes arabicus (Kirchberg) P JB, JF

*Prionotheca coronata ovaiis Ancey P JF

*Prionotheca coronata Olivier P JB

*Akis eievata Solier P JB, BJT

*Akis eievata f. scuiptior Koch P JF

*Eurycauius granuiatus Reitt. P JB

*Eurycauius buettikeri Schawaller P JF

*Leichenum mueiieri Gridelli P JF

Zoptiosis migneauxi Deyr P JB

Nr Stenosis ?sp P JB

Cerambycidae Acanthophorus arabicus Thom s H BJT, JB

Buprestidae *Juiodis whithiiii Gray H JB

Juiodis sp. H JB

Acmaeodera? Sp. P JB

*Chrysobothris parvipunctata Obenb. M JB

A ppend ix 4.1 Continued List of species caught in UAE (1992-1996).

248

Class Order (Division) Family Genus & Species (if known) M ethod Verified

(subfamily) of bycap ture

Insecta Coleoptera Scarabaeidae Scarabaeus cristatus F L. P JB

*Phyllognathus excavatus L BJT

*Distichus planus Bow. L JB

*Dynamopus semenowl Arrow L JB

Aphodius translucidus Petr. L JB

Aphodius indet. L JB

*Poda!gus cuniculus L JB

Catharslus inermis Castelnau L JB

Melolonthina indet. L JB

(Scarabaeinae) indet. H JB

(Rutelinae) indet L JB

(Hybosorinae) *Onthophagus ochreatus D'orb L JB

Anthicidae *Mecynotarsus nr semicinctus W oil. P JB

Indet. P JB

Bostrichidae *Sinoxylon senegalenesis M JB

"Phonapate arabs Lesne H JB

Cleridae *Necrobia rufipes (D e Gerr) P JB

Dermestidae ”Anthrenus flavipes LeConte H JB

Meloidae indet. P JB

Ptillidae Indet. P JB

Crustacea Isopoda Porcelinidae Porcelinidae? P JB

Chilopoda Scolopendromorpha Scolopendrida Scolopendrida mirabilis P BJT

Vertebrata ReptiliaSquamata Agamidae Phrynocephalus arabicus Anderson P PEO

Gekkonidae Bunopus tuberculartus Bianford P PEO

Stenodactylus arabicus (H aas) P PEO

Stenodactylus dorlae Bianford P PEO

Stenodactylus leptocosymbotes Leviton P PEO

& AndersonStenodactylus slaveni Haas P PEO

Teratosclncus sclncus (Schlegei) P PEO

Lacertidae Mesallna adramitana Bianford P PEO

Scincidae Sclncus mitranus Anderson P PEO

Sclncus sclncus conlrostris (Bianford) P PEO

Serpentes Leptotyphlopidae Leptotyphlops macrorhyncus (Jan) P PEO

Appendix 4.1 Continued List of species caught in UAE (1992-1996)

* indicates new records for UAE and new species have been shaded. For a

complete checklist of the country use both Appendices 1.1 and 4.1.

P= pitfall trap, L= light trap, H= hand searching or netting, M= Malaise trap, F=

fragment recovered from houbara faeces, B= baiting (for ants).

See over-leaf for list of taxonomists involved in species identification and

verification.

249

List of collaborators for species identification and verification

Initials Full Name Place of work or study

AB Dr Anne Baker The Natural History Museum, London, UK

AW Dr Annette Walker The Natural History Museum, London, UK

BUT Barbara Tigar NARC, UAE & University of Stirling, UK

CAC Cedric Collingwood Leeds City Museum, Leeds, UKDA Dr Donat Agosti American Museum of Natural

History, NY, USAEBW Ted Wiltshire QBE The Natural History Museum,

London, UKGP Dr George Popov MBE The Natural History Museum,

London, UKGS Gary Stonedahl The Natural History Museum,

London, UKIW 1. White The Natural History Museum,

London, UKJB John Boorman The Natural History Museum,

London, UKJC John Chainey The Natural History Museum,

London, UKJF Dr Julio Ferrer Swedish Museum of Natural

History, Stockholm, SwedenLS Dr Lou Sorkin American Museum of Natural

History, NY, USAMS Michael Schaffer The Natural History Museum,

London, UKMW M. Wilson The Natural History Museum,

London, UKNW Nigel Wyatt The Natural History Museum,

London, UKPEG Dr Patrick Osborne NARC, UAE & University of

Stirling, UKPH Paul Hillyard The Natural History Museum,

London, UK88 Sharon Shute The Natural History Museum,

London, UKRT Richard Thompson The Natural History Museum,

London, UK

Appendix 4.1 continued List of species caught in UAE (1992-1996) (collaborators).

250

Prey group Prey genus Bird ID Date of trial Ratio of prey (start:end)

2 Messor O/FJ0 /D N0/C U0/C U0/C S

12/03/9520/03/9520/03/9518/04/9520/03/95

250:6250:243250:21144:143250:5

3 Ocladius O/FJ0 /D N0/C U0 /0 8

28/03/9506/03/9512/03/9512/03/95

20:021:1418:018:0

4 Mesostena O/FJ0 /D NG/CPO/CU0/C SG/FT0 /F F

G/BH*

26/02/9521/12/9412/11/9422/01/9503/04/9512/11/9412/11/9430/10/94

50:050:1350:150:050:750:0

50:5050:0

5 Tentyrina O/FJG/CP0 /F FG/FT

21/12/9427/11/9427/11/9427/11/94

43:050:050:0

45:45

6 Akis O/FJ 22/01/95 18:10

BlapsPimelia

Ocnera

0 /D N

G/CP0 /D N0 /F F0 /C U0/C S0 /C A

22/01/95

19/11/9418/04/9419/11/9421/12/9522/01/9527/11/94

30:17

20:06:5

20:240:2840:3250:46

7 Anthia O/FJO/FJ0 /D N0/C U0/C S

20/03/9518/04/9528/03/9503/04/9528/03/95

2:05:06:610:07:6

8 Locusta

Pyrogomorpha spp.

O/FJ0 /D N0/C U0/C SG/CP

19/02/9505/02/9505/02/9505/02/9521/12/94

7:015:015:015:111:5

10 Vachoniolus & Buthacus

Vachoniolus

O/FJ0 /C S0/D NG/CP0/C U

03/04/9506/03/9529/01/9522/01/9529/01/95

3:03:03:01:03:0

12 Bunopus O/FJ0/D N0/C U

06/03/9503/04/9506/03/95

2:02:02:0

13 Mus(hairless baby mice)

O/FJ0/D NG/CPG/CP0/C U0/C S

29/01/9519/02/9529/01/9519/02/9519/02/9519/02/95

5:05:05:01:05:05:0

13 Mus (adult mice)

O/FJO/FJ0/D N0/D NG/CP0/C U0/C U0/C SO/CS

05/02/9510/04/9510/04/9526/02/9505/02/9526/02/9510/04/9526/02/9510/04/95

5:03:03:25:05:05:03:05:23:3

16 Erodius 0 /D N0 /C U0/C S

12/03/9528/03/9512/03/95

22:2220:03:0

Appendix 5.1 : List of feeding trials by prey group, genus, bird identity (leg band), date and ratio of number of prey at the start to end of each trial. Groups 1,9, 11, 14 and 15 were not tested because of lack of prey. Bird G/CP died of natural causes and G/BH, a C.U.undulata in an outside pen, was used in a pilot test.

251

Appendix 5.2

Preliminary Study of the Rate of Passage of Digesta in Houbara bustard

by Tigar, B. J. (1995).

National Avian Research Center Internal Report Number 5 1995

252

Preliminary Study of the Rate of Passage of Digesta in Houbara bustard

Barbara Jane Tigar

Rate of passage through the gut of the houbara was investigated in two separate trials on four birds in Sweihan Quarantine Centre. Plastic pellets were used as a marker and were given to the birds in a mash of houbara feed pellets. Different coloured markers were given on three consecutive days and their consumption was highest on the first day and lowest on the third. Overall consumption of plastic pellets was low and highly variable both between experiments and individual birds. The first pellets to be recovered appeared within three hours and the majority recovered were obtained within 24 hours. One sample appeared after 37 days and may have been either a contaminant or may have been retained by the gizzard. Fewer plastic pellets were consumed in the second trail than the first. Reasons for the variation are discussed and ways to improve such work in the future are suggested. This includes a summary of a review of experiments on passage time which has recently been added to our library. It is highly relevant and contains much useful information on the limitations, design and statistical analysis of such trials.

Introduction

The Houbara Feeding Ecology Program is primarily concerned with the diet of wild houbara in Abu Dhabi. However, a series of experiments was carried out using captive birds to enable us to identify and quantify invertebrate remains in faeces. The tests were carried out in Sweihan Quarantine Centre (SQC) and upon completion the experimental birds were kept a further six weeks to investigate the rate of passage through the gut. This is defined by Warner (1981) as the time taken for an individual portion of digesta to be mechanically mixed, digested, absorbed and excreted.

Warner's (1981) review of the rate of passage in birds and mammals was not available at the start of the experiments but may have influenced the experimental design and choice of marker. He points out that three important factors influence all experiments on the rate of passage:

1. There is usually a large coefficient of variation and many replicates are needed to demonstrate small effects.

2. The amount of food consumed during the experiments affects the retention time and ad lib intakes are difficult to interpret.

3. Different components of the diet may have independent passage rates and markers must behave in a similar manner to the experimental diet.

Points two and three are relevant to our work because the marked food was left with the birds for 12 hours and plastic beads were used as the marker and it is unlikely that they behaved in a similar way to the houbara diet.

The speed of the passage through the gut has implications for several areas in which NARC has an interest, particularly the rate at which drugs are absorbed and the time taken for non- digestible fragments to appear in faeces. For example, a single meal may appear in numerous faeces which are voided at different times. Differential digestion of various items may also affect the rate of passage time. Data from the feeding trials with invertebrate prey will also increase our understanding of these factors. However, the aim of this study was to establish a standard determination of passage time which could be used as a reference for the interpretation of both faecal analysis and pharmokinetic studies in houbara.

Methods

Experimental Conditions

The four Chlamydotis undulata macqueenii used in the trails were fed a diet consisting solely of dry houbara maintenance pellets from November 1994 until June 1995. Each bird was given 75 g of pellets per day (i.e. excess food) and food intake was monitored and is

Appendix 5.2 Tigar, B. J. (1995). Preliminary Study of the Rate of Passage of Digesta inHoubara bustard

253

presented elsewhere (Mitchell, in prep.). The birds were housed in individual, air conditioned chambers allowing separate faecal samples to be collected from each bird. The chambers had interconnecting hatchways so that birds could be moved to the adjoining chamber during sample collection and thereby minimising stress.

Experimental Procedure

Two similar trials were carried out; the first started and on 30th April 1995 and the second on 5th June 1995. At 15.00 hr the day prior to the experiment all existing food was removed and at 07.00 hr the following day a 1:2 by weight mixture of plastic pellets and maintenance pellets was given to the birds. Therefore each bird had 37.5g plastic pellets and 75g dry maintenance pellets all mixed together with enough water to make a moist (but not watery) mash or paste. The plastic pellets were clearly visible in the mash. It was thought unlikely that the birds would eat all the pellets, but by giving them excess they would pick up a reasonable amount. After the three days of mash they were returned to their normal feed pellet diet.

Faeces were removed once every three hours between 07.00 and 19.00 on days the birds were fed a plastic pellet mash and then twice a day at 12 hour intervals for two to three days (depending upon availability of staff). Daily faecal collection continued for up to 8 days after the initial pellet mash, during the morning feed. Faeces were counted and placed in separate bags and labelled with the bird ID, date and time of removal. The faeces were placed in a 200 and 500pm sieve and washed under a stream of running water to separate out the plastic pellets, which were then dried and weighed. At 19.00 the mash was removed and the plastic pellets separated using the sieves in a similar way. They were then dried and weighed so that percentage recovery could be calculated. The next day a different coloured pellet was added to the food and the same sequence of events carried out. Three colours were used per trial: orange, mauve and light yellow for the first trial and green, red and bright yellow for the second.

Some of the pellets contained tiny perforations where minute fragments of food and faeces became imbedded. A correction factor for the weight of pellets recovered from faeces was calculated by weighing three replicates of 100 dry, unused pellets and 100 pellets recovered from the mash or faeces (the latter was only possible for orange).

The resulting data set suffered from being highly variable and was based on only a limited number of observations. Where sufficient data were obtained the combined cumulative percentage recovery of the birds was plotted as a curve produced by log smoothing using SYSTAT (Wilkinson etal, 1992). Most of the trends in the data were obvious and no further statistical analysis was carried out because of the limited nature of the data.

Results

Table 1 shows the correction factors for the three colours in the first trail and the weight of plastic pellets recovered from the mash given to the birds. The latter is equivalent to the weight ingested assuming no loss during recovery of plastic pellets from food, sieving, washing and drying.

OrangeColourMauve Light Yellow

Correction factor 0.9857 0.9828 0.9837Bird ID Weight ingested (g)

FJ 3.15 1.89 0.59DN 4.36 1.93 0.79CU 3.66 0.72 0.39OS 0.00 0.00 0.00

Table 1 Correction factors and quantity of pellets ingested during the first trial


254

Table 1 also shows that there was a decline in the amount of plastic pellets consumed with most taken on the first day (orange), fewer on the second (mauve) and virtually none on the third (light yellow). One of the birds, CS, did not eat any plastic pellets.

Cumulative percentage recovery of the three colours from faeces during the first trial is plotted against time lapsed from the start of the trial (Figures 1 to 3). Data points from individual birds are represented by the same symbols in all the figures i.e. a circle for FJ, a small diamond for DN, and a square for CU. The curve was produced by log smoothing of the combined data. The time axis indicates the number of days since the start of the experiment. Therefore mauve pellets do not appear until after day two and light yellow pellets after day three.

60

50

40

30MI 20 Ü

0 2 3 5 6 7 81

Time (days)

Figure 1 Plot of cumulative percentage recovery for orange pellets

60

50

%40

X 30

20O

80 2 3 5 6 71

Tim e (days)

Figure 2 Plot of cumulative percentage recovery for mauve pellets

X 30

0 1 2 3 4 5

Time (days)

Figure 3 Plot of cumulative percentage recovery for light yellow pellets


255

The highest cumulative percentage recovery of pellets from faeces was 58% of mauve from DN samples and occurred between three and four days after the start of the trial, i.e two to three days after ingestion. However, most of the recovered pellets were obtained within 24 hours of ingestion, seen as a rapid increase followed by a levelling out of the curves in Figures 1 to 3. A higher percentage of orange pellets was recovered from FJ and very few light yellow pellets were either ingested or recovered from any of the birds.

RedColourGreen Yellow

Correction factor 0.9457 0.9900 0.9855Bird ID Weight ingested (g)

FJ 0.30 0.12 0.03DN 0.01 0.03 0.03CU 0.16 0.02 0.06CS 0.04 0.03 0.00

Table 2 Correction factors and quantity of pellets ingested during the second trail

Table 2 shows the correction factors and amount of pellets ingested in the second trial. Fewer plastic pellets were ingested than in the first trail and apart from red and green for FJ and red for CU pellet intake was negligible (less than 0.1 g). Again there was a decrease in the amount of pellets taken, with most being consumed on day one, in this case red pellets.

The cumulative percentage recovery of red and green pellets is shown in Figure 4. The top curve represents red and is based on 5 data points from FJ and one from CU, the bottom curve is for green and is based on only two data points from FJ.

80

70

60

50

I30

Ü

0 2 3

Time (days)

Figure 4Plot of cumulative percentage recovery for red and green pellets

One unusual result was that a single mauve pellet was recovered from CU on 6th June 1995. Assuming that this was from the first trial and not a contamination then it took 37 days to be voided by the bird.

Discussion

Time for recovery of the first sample was fairly rapid, within three hours for FJ. This is similar for other birds species, for example Duke e ta /(1968) recovered the first marked sample from the ring-necked pheasant in 1.5 hours and the last in 8.5 hours. The latter authors also measured the through-put time of the caecae which was slower, with the first sample appearing at 6.6 hours and the last at 39 hours. However, the last sample we recovered appeared after 36 days. This may suggest that plastic (or other) beads are not suitable for this type of study because they act like grit and are retained to aid the crushing action of the gizzard. This retention may also apply to invertebrate and other hard remains in faecal samples. Analysis of the captive bird feeding calibration trails should help illuminate any such


256

affects. The only way to be sure that no further pellets remain would be to euthanase the birds and examine their gizzard contents which is not considered justifiable for this trial.

The reason for the small intake of plastic pellets by the birds is unclear. It may indicate that they were actively avoiding them or had a preference for particular colours e.g. orange. It is also possible that they did not find the mash mixture as palatable as their usual diet of dry pellets, although such a mash with various additional ingredients is given to most of NARC's birds. However, it can go rancid and quickly spoil, and mould growth was noted on the top of the mash when separating the plastic pellets in the lab the next day. Whatever the reason, the small quantity of pellets ingested meant that any inaccuracy in recovering and weighing the pellets had a large effect on the percentage of pellets recovered.

There was some variation in the consumption of plastic pellets by the different birds, with FJ and DN taking the most. CS took none at all and fewer were taken by the other birds in the second trial which may suggest avoidance (although since different colours were used it is hard to say). Intake of plastic pellets may be related to the normal food intake of the birds. Records of daily food consumption may show that some birds always eat more than others and so automatically ingested more plastic pellets (Mitchell, in prep). 0 8 and DN were females and when weighed on 22nd March 1995 registered 1090g and 1009g respectively.FJ and CU were males and therefore heavier than the females, weighing 1304g and 1647g respectively. This is a very small sample size but there was no obvious effect of weight or sex on the intake of plastic pellets. However, daily consumption of food pellets by captive houbara is highly variable (Jacquet, in prep; Mitchell, in prep) and it may just have been a natural low in food intake rather than an avoidance of the pellets by individuals.

It is possible that some plastic pellets were not recovered from either the food dish or faeces. The chamber floor was covered with a layer of sand, and plastic pellets could easily have been coated with sand especially when wet. If the birds had taken more of the plastic pellets such losses would have had less effect. Warner (1981) also concedes that it is often difficult to get 100% recovery of many types of markers due to unknown causes.

Problems during the trials

During sample collection the birds were moved to the adjoining room to avoid stress caused by the researcher entering in the room. However, all these birds were wild- caught adults and often showed signs of distress including defaecation on being moved. This was probably a defensive action and there is evidence that houbara defaecate onto attacking falcons to deter them (Cramp & Simmonds, 1980) and as a preparation for flight when alarmed (personal observation). In the wild, houbara appear to defaecate fairly frequently as indicated by the high rate of encounter of faeces along their tracks (pers. observation), so through-put time is probably always fairly rapid. However, too frequent a visit to the study birds may have stressed them and affected their behaviour increasing the speed of the gut and number of samples.

The pellets and food pellets were given as a mash but it was possible for the birds to avoid the colours. A more viscous mixture of foods would make it easier to conceal the plastic pellets and harder for the birds to avoid or remove them. Peanut butter is used to conceal the plastic pellets from badgers (C. Cheeseman, in lift.) and this might be suitable for houbara although it is not a natural food item and may not be palatable to the birds. A mixture of mince or even placing the pellets inside mice might work although any change in the diet might also affect the through-put time.

Gut length is known to be affected by diet for other birds and switching from a captive based diet of concentrated food such as pellets, to a natural based, higher fibre content diet has been shown to increase the gut length in red grouse (Moss & Parkinson, 1972). However, the quantity of fibre may also affect retention time, and Mattocks (1971) found that in geese, grass started to appear in faeces 1.7 hours after feeding while meal (lower fibre but higher nutritional content) took only 1.3 hours. Originally a trial using a mixed diet like that given to most captive birds at NARC had been planned, i.e. switching to a mixture of soaked houbara pellets, minced meat, cabbage and apple. This could be used to examine any differences in through-put time and the affect of changing the diet over say a four week period. However, it


257

was decided not to attempt this because of poor consumption and recovery of the plastic pellets from the maintenance pellet trail.

Future work.

This work was carried out after the trials with invertebrate prey because it was thought to be relatively simple to execute and resources were available at the time. Manpower is not currently available to develop these techniques and preliminary results and the review of Warner (1981 ; see summary below) show that such studies are more complicated than anticipated. If in the future such work becomes a higher priority the following comments on choice of marker and experimental design, based on Warner (1981), should be taken into account and a full literature search carried out.

Choice of marker

Markers can be divided into four categories, but no practical marker is ideal although all can give an approximate rate of passage. Choice of marker will depend on the species being studied and resources available (some can only be detected by sophisticated analytical techniques or x-rays). The list below explains the biases that affect recovery of different types of markers from faeces.

1. Normal dietary constituents such as lignin.The recovery of all dietary markers is difficult to measure accurately and they may also suffer some digestion.

2. Solute markers which probably stay in solution in the gut, for example polyethylene glycol (PEG) and the chromium complex of ethylenediamine tetra-acetic acid (EDTA).It is not known how solute markers are distributed between the free gut fluid and the fluid within the digesta, which affects the time of detection in faeces. Some adsorption into the bloodstream may also occur.

3. Particulate markers such as chromic oxide and radio-opaque plastic pellets. The plastic pellets we used come into this category.All particulate markers probably differ in size, specific gravity or surface properties from the food and so may behave differently from it. Size has been shown to effect the rate of passage of particulate markers in mammals with a trend for smaller sizes to pass more rapidly. Substances of a high specific gravity are retained for longer, particularly in the stomach and caecum. Plastic pellets of specific gravity 1.12 had a mean retention time of about 60 hours in cattle fed on hay, but this increased to 110 hours when fed on a concentrate diet (Campling & Freer, 1962).

4. Particle markers which are originally in solution but become embedded in food e.g. stains and the ruthenium-phenathroline complex.Particle markers have been shown to transfer between particles and may be adsorbed into the bloodstream.

Experimental design

The simplest experimental design is to use a pulse dose, i.e. the marker is given as single pulse (discrete meal) and then the faeces are collected at regular intervals. Passage rate may vary according to the frequency of feeding and the time between each feed. In geese, dietary markers travelled more slowly when given mid-meal than when given on an empty gut (Mattocks, 1971). The recovery pattern for the marker should give a sigmoid curve. Various calculations and indices are discussed by Warner (1981), particularly the time to excrete a certain percentage of the marker which is a common theme in many papers. For example, useful reference points are the time for first recovery of marker, which is often termed transit time or t , and the time for half the marker to be recovered also called half time or t o- Warner recommends calculating the mean recovery time, which is the average time of retention of all the digesta being studied and presents mathematical formulae for calculating the defined parameters. If the passage time for different segments of the gut is required, radio-opaque markers and x-rays must be used, or the experimental animals killed and dissected.


258

Warner (1981) highlights the complexity of this topic and factors which must either be controlled or accepted as biases. Sufficient replication is very important as there may be tremendous variation between individuals of the same species. Future studies of houbara should avoid the use of particulate markers. Actual choice of marker will depend on resources and equipment available, but a preliminary trial to investigate the best markers should be carried out. We originally tried using colour dyes in our trials (Mitchell, in prep.) but we could not detect their presence in the faeces probably because they were either digested or absorbed by the bloodstream. It maybe worthwhile looking at both solid faecal and caecal faecal through-put times. We did not differentiate between the them in this trail and it is sometimes hard to do so because they are present within a single sample (personal observations). Mean retention time as suggested by Warner (1981) would be a good reference value to aim for. We were unable to calculate it because of the poor recovery of markers.

Acknowledgements

The coloured plastic pellets were kindly provided by Dr Chris Chessman of Central Science Laboratory, UK and his work on badger territorial ranges acted as an inspiration for using them in these trials. William Mitchell is duly thanked for many hours of technical assistance, in particular for collecting and processing of samples. Dr Patrick Osborne is thanked for his advice on data handling and analysis. Judith Howlett, Mohammed Nafeez and Dr Jaime Samour of Veterinary Science Department are also thanked for their help at SQC.

References

Campling, B.C. & Freer, M (1962). The effect of specific gravity and size on the mean time of retention of inert particles in the alimentary canal of the cow. British Journal of Nutrition 16, 507-518.

Cramp, S. & Simmons, K.E.L. (1980). Handbook of the Birds of Europe, the Middle East and North Africa. Vol.2. Hawks to Bustards. Oxford University Press.

Duke, G.E., Petrides, G.A. & Ringer, R.K. (1968). Chromium-51 in food metabolizablity and passage rate studies with the ring-necked pheasant. Poultry Science 47,1356-1364.

Jacquet, J. M. (in prep). Food intake in the houbara bustard, relation with body weight and ambient temperature. NARC Internal Report Series

Mattocks, J.G. (1971). Goose feeding and cellulose digestion. Wildfowl 22,107-113.Mitchell, W. L. (in prep). Sandwich student placement report 1994-95. NARC Internal Report

SeriesMoss, R. & Parkinson, J.A. (1972). The digestion of heather {Cailuna vulgaris) by red grouse

{Lagopus lagopus scoticus). Br. J. Nutr., 27, 285-298 Warner, A.C.I. (1981). Rate of passage of digesta through the gut of mammals and birds.

Commonwealth Bureau of Nutrition, Nutrition abstracts and review series ”B", 51, 789-819.

Wilkinson, L., Hill, M, Howe, P & Miceli, S. (1992). SYSTAT for Windows, Version 5 Edition. Evanston, IL: SYSTAT, Inc., 1992.


Prey group Description Remains likely to be present in faecal samples

Tough, square-shaped head capsule is usually intact. Jaws typical, “hand-like” shape, occurring loose and hidden inside head capsule. Pieces of cuticle, propodeums and typical legs seen floating on the surface tension of samples.

1 & 2 Nocturnal and diurnal ants.HymenopteraiFormicidae

3 Phytophagous, plant dwelling insects e g weevils

4 Nocturnal, small tenebrionids e.g Mesostena puncticollis

5 Diurnal, small, plant climbing tenebrionids Coleoptera:T enebrionida e Tentyrina palmen

6 Large, noctunral tenbrionids

7. Fast-moving, predatory carabid beetles

8 Fast-moving, plant dwelling insects (can fly or jump)Orthoptera:Acridida

9 Very fast, large predatory arachnids. Solifugae

10 Slow, large predatory arachnids. Scorpionae

11 Diurnal Reptilia12 Nocturnal Reptilia13 Rodentia14 Fast moving, small

predatory arachnids Aranea

15 Diurnal/nocturnal aerial insects

16 Large diurnal tenebrionids

Weevils are highly sclerotised and usually covered in scales which are worn-off during digestion. When threatened they withdrawn their appendages close into the body, and a few almost complete bodies were recovered. They have characteristically shaped limbs and their femora are distinctive and easy to identify for each species. They are often attached to tibia. Head and rostrum, tarsi, disk, prosternum (often fused to disk), elytra (with evidence of scales), sternites (usually fused together) also recovered less frequently.A variety of fragments, including jaws, heads, tibiae and femora were recovered during the trials M.puncticollis has a row of tiny serrations at front of head capsule, parallel rows of dots along the elytra, and a very shiny, smooth thoracic disc. Other species identified on the shape of their femoraT.palmeri has no serration at front of head capsule but a small peg-like, off-centre projection is present. The elytra are plain and smooth. Two dimples are present on the thoracic disk. When large numbers are eaten some beetles remain almost complete following digestion.

Much finely-ground, black material present following digestion, e.g. fragmented elytra, thorax and head, but the jaws often remain intact and femora are recovered in large numbers, although they maybe broken. If broken count leg joint only. Sometimes tibia are a similar size to femora, but they are usually more flattened.Most remains are finely ground but the distinctive, large sickle-shaped mandibles and notched tibia are conspicuous.

Generally very well digested. However, the mandible are usually intact, although they may be broken into two halves. The femur joint is often present.

Very characteristic long, orange hairs can be seen in the sample. The highly sclerotized jaws or chelicerae may be present.

Body highly fragmented, but fragments fluoresce under UV light. Occasionally a chelicera may be recovered.

Possibly a few scales. No bones recovered from wild or captive birds Possibly a few scales. No bones recovered from wild or captive birdsFur seen as glossy film on surface tension of sample or compact and matted fur-balls. Bones and teeth not recovered in trials. Chelicera and hairs might remain. Silken cocoons also possible.

Femur and metallic cuticle of Buprestids very distinctive. Characteristic, spiny fore-limb and front of head indicate dung beetles.

Generally rotund beetles with distinctive, half-moon shaped thorax. Adesmia spp. fragments have a blue metallic sheen. All have species specific sculpturing on first femur.

Appendix 5.3 Description of invertebrate prey remains recovered from faecal samples, with prey groups according to Table 4.1 rocnCD

260

: î

9

Group 1 Head capsule of Camponotus xerxes Group 2 Head capsule of Messor sp

Group 3 Femora and tibiae of Ammocleonus sp Group 3 Lateral view of Ammocleonus sp headcapsule

«WKNI

_____________Group 4 Head of Mesostena puncticollis showing small, angular eyes

Group 4 Close-up of M. puncticollis head showing small eyes and serrated front edge

Group 4 Elytrum of M. puncticollis showing parallel rows of dots.

Group 4 Fore-, mid- and hind-femora of M. puncticollis

Appendix 5.4 Photographs of typical fragments from the invertebrate prey groups.

261

Group 5 Head of Tentyrina palmeri showing large round eyes

Group 5 Close-up of T. palmeri head with large eyes and projection at front of head

Group 5 Fore-, mid- and hind-femora of T. palmeri

Group 5 Elytrum of T. palmeri

ft I t 3 4 ,: :5 S ? ' $ « |

Group 6 Wax-covered femora of Ocnera philistina

Group 6 Fore- and mid-femora of Blaps koliari

0M______________

'

'*

Group 6 Fore-, mid- and hind-femora of Akis elevator

Group 6 Fore-limb of Paraplatyope popovi showing distinctive tibia


262

.. .

Group 7 Sickle shaped-jaws of Scarities guineensis

Group 7 Sickle-shaped jaws of Anthia duodecimguttata

_______ _Group 9 Chelicerate mouthparts of camel spider, Galeodes sp.

Group 15 Fore-tibia of Sacer christatus

Group 15 Head capsule of Sacer christatus, showing spines at front edge

Group 15 Buprestid femora, showing pitted surface

4.%% y ^Group 16 Erodius sp, fore-limb, with fringes of Group 16 yApenfanoc/es sp limbs, note the largehair on femur and spine on tibia fore-limb


263

Group 16 Hind-limb of Adesmia sp. Group 16 Fore-, mid- and hind-limbs of Adesmia sp.


264

Sampleno.

Date PlaceGPS (UTM)

Easting Northing Sampleno.

Date PlaceGPS (UTM)

Easting Northing

1 18-Mar-93 Merowah unknown unknown 55 11 -Nov-93 Baynunah 640002 2644976



4 21-Mar-93 Merowah unknown unknown 58 11-Nov-93 Baynunah 640019 2644807




8 21 -Mar-93 Merowah unknown unknown 62 11-Nov-93 Baynunah 640040 2644823







19 10-Dec-93 Baynunah 659681 2654173 69 11-Nov-93 Baynunah 639452 2644646

20 IO-Dec-93 Baynunah 659658 2654219 70 11-Nov-93 Baynunah 639452 2644646

21 10-Dec-93 Baynunah 659423 2654421 71 11-Nov-93 Baynunah 639452 2644646

22 IO-Dec-93 Baynunah 659433 2654540 72 11-Nov-93 Baynunah 639452 2644646

23 IO-Dec-93 Baynunah 659746 2653916 73 11 -Nov-93 Baynunah 639453 2644646

24 IO-Dec-93 Baynunah 659736 2653095 74 11 -Nov-93 Baynunah 639453 2644646

25 IO-Dec-93 Baynunah 659661 2652933 75 16-NOV-93 Baynunah 659215 2655624


27 10-Dec-93 Baynunah 659518 2652846 77 17-NOV-93 Baynunah 659705 2655062


29 IO-Dec-93 Baynunah unknown unknown 79 18-NOV-93 Baynunah 653954 2654678

30 25-Oct-93 Baynunah 645587 2655737 80 18-NOV-93 Baynunah 656074 2653983

31 25-Oct-93 Baynunah 645591 2655668 81 18-NOV-93 Sila 588655 2635894







38 22-Oct-93 Abu Dhabi unknown unknown 89 25-NOV-93 Baynunah 645490 2656433






44 11-Sep-93 Baynunah unknown unknown 95 26-NOV-93 Baynunah 640480 2644247





49 11-Dec-93 Baynunah 641764 2644624 100 26-NOV-93 Medinat Z. 198816 2635280

50 11-Dec-93 Baynunah 641794 2644617 101 12-Aug-93 Baynunah 659156 2654367

51 11-Nov-93 Baynunah 639952 2644781 102 12-Sep-93 Baynunah 659006 2654036

52 11 -Nov-93 Baynunah 640030 2644914 103 12-Sep-93 Baynunah 658975 265393453 11 -Nov-93 Baynunah 640022 2644937 104 12-Sep-93 Baynunah 660857 265403254 11-Nov-93 Baynunah 639999 2644968 105 12-Dec-93 Baynunah 591848 2644966

Appendix 5.5 List of houbara faeces.

265

Sampleno.

Date PlaceGPS (UTM)

Easting Northing Sampleno.

Date PlaceGPS (UTM)

Easting Northing

106 13-Dec-93 Baynunah 661349 2654402 137 02-Sep-94 Baynunah 642270 2551500




110 20-Dec-93 Baynunah 640512 2635901 141 30-Oct-94 Baynunah 642732 2602759







117 22-Dec-93 Oishtan 641879 2649302 148 27-Oct-94 Baynunah 678701 2650850

116 01-Oct-94 Baynunah 660802 2653781 149 19-May-94 South 248529 2568646

119 01-Mar-94 Baynunah 660848 2653003 150 20-May-94 South 248607 2568347




123 01-Apr-94 Baynunah 662393 2654150 154 20-May-94 South 248607 2568347124 01-Apr-94 Baynunah 662292 2654088 155 19-May-94 South 248529 2568646125 01-Apr-94 Baynunah 657590 2653021 156 19-May-94 South 248529 2568646126 01-Apr-94 Baynunah 660953 2654149 157 20-May-94 South 248607 2568347127 23-Jan-94 Baynunah 660890 2654053 158 20-May-94 South 248607 2568347128 23-Jan-94 Baynunah 660953 2654149 159 19-May-94 Baynunah 248529 2568646129 23-Jan-94 Baynunah 660752 2654172 160 20-May-94 Baynunah 248529 2568646130 23-Jan-94 Baynunah 660698 2654152 161 20-May-94 Baynunah 248529 2568646131 15-Feb-94 Baynunah 638882 2647694 162 19-May-94 Baynunah 248529 2568646132 02-Apr-94 Baynunah 660922 2654159 163 03-Sep-95 Baynunah 24.009 52.738133 02-Apr-94 Baynunah 660881 2654040 164 03-Sep-95 Baynunah 24.009 52.738134 02-Sep-94 Baynunah 642258 2651510 165 22-Apr-94 unknown unknown unknown135 02-Sep-94 Baynunah 642267 2651507 166 11-Apr-95 Baynunah unknown unknown136 02-Sep-94 Baynunah 642270 2551500 167 20-May-94 Baynunah 248607 2568347

Appendix 5.5 continued List of houbara faeces collected In UAE GPS= Global Positioning System and UTM= Universal Transverse Mercator Captive birds (15-18) and caecal faeces (128 & 165) were excluded from calculations In Chapter 5

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