BIOLOGICAL

CONSERVATION

Biological Conservation 118 (2004) 175–181

www.elsevier.com/locate/biocon

Non-commercial collection of spur-thighed tortoises(Testudo graeca graeca): a cultural problem in southeast Spain

Irene P�erez a,*, Andr�es Gim�enez b, Jos�e Antonio S�anchez-Zapata b, Jos�e Daniel Anad�on b,Marcelo Mart�ınez a, Miguel �Angel Esteve a

a Dpto. Ecolog�ıa e Hidrolog�ıa, Facultad de Biolog�ıa, Universidad de Murcia, Campus de Espinardo, 30100 Espinardo (Murcia), Spainb �Area de Ecolog�ıa, Dpto. Biolog�ıa Aplicada, Universidad Miguel Hern�andez, Campus de Orihuela, 03312 Orihuela (Alicante), Spain

Received 3 September 2002; received in revised form 31 July 2003; accepted 31 July 2003

Abstract

Collecting tortoises for the pet trade is one of the factors threatening species of Testudo in the Mediterranean area. The collection

of Testudo graeca graeca for pets is described in southeast Spain, where the main European population of this subspecies coincides

with an area where keeping tortoises in captivity is a long-established custom. This present paper, based on inquiries made to

children, reveals that this practice continues to be a common activity, and estimates a captive population in the order of tens of

thousand of tortoises. Tortoises are collected as a result of chance encounters with wild animals by local inhabitants, and without

any commercial objectives. The captive breeding and the release of tortoises without any institutional control is also common. These

activities could be an important threat for the species. Implications for conservation are discussed and a critical review of the

conservation strategies developed in relation to this threat (trade control and re-introduction programmes) are presented. We

suggest that environmental education programmes are necessary to reduce casual collection and to change the social perception of

tortoises as pets.

� 2003 Elsevier Ltd. All rights reserved.

Keywords: Species conservation; Captivity; Non-commercial collecting; Wildlife attitudes and value scales; Testudo graeca graeca

1. Introduction

Human collection of plants and wild animals is a

response to several needs and its origins lie in the har-

vesting of plants and fruits and in hunting and fishing

for human consumption by local populations. In mod-

ern societies, these activities have led, on the one hand,to sport hunting and fishing, and, on the other, to an

increase in the scale of collection for economic and

commercial motives. This has become especially signif-

icant in the harvesting of animals in large-scale fishing

(Caughley and Gunn, 1996) or for their skins (Shine

et al., 1996; Fitzgerald et al., 1993), as well as the use of

animal parts in traditional medicine (Hemley and Mills,

1999) and the trade and traffic of live animals for use as

* Corresponding author.

E-mail address: ireperez@um.es (I. P�erez).

0006-3207/$ - see front matter � 2003 Elsevier Ltd. All rights reserved.

doi:10.1016/j.biocon.2003.07.019

pets, as is the case for birds (Christian et al., 1996) or

tortoises and turtles (Thorbjarnarson et al., 2000).

The survival of wild species can be threatened by

direct activities, e.g. elephants hunted for their ivory

(Milner-Gulland and Mace, 1991; Tchamba, 1996), or

through indirect activities such as the capture of ceta-

ceans or marine turtles in fishing nets designed for otherspecies (Chan et al., 1988). Thirdly, species may be

collected through chance encounters, although the ef-

fects of this practice have seldom been studied.

Many species of tortoises face conservation problems

induced by humans, which have even led to the recent

extinction of some species (Honneger, 1981; Thorb-

jarnarson et al., 2000). In most cases, threats include the

alteration or loss of suitable habitats, and the collectionof animals for food or for the pet trade (Klemens and

Thorbjarnarson, 1995; Thorbjarnarson et al., 2000).

The collection of tortoises for the pet trade is un-

doubtedly an important threat for some species, for

Fig. 1. (a) Distribution of T. graeca graeca in the Mediterranean area; (b) distribution of T. graeca graeca in Southeastern Spain, provinces of

Almer�ıa (from Andreu, 1988) and Murcia (from Gim�enez et al., 2001); (c) study area in the province of Murcia. Dark grey indicates the districts

inside the distribution area of the species and light grey indicates the districts outside the distribution area of the species.

176 I. P�erez et al. / Biological Conservation 118 (2004) 175–181

example Geochelone chilensis in Argentina (Buskirk,

1993; Waller, 1997; Pujol, 1998) or the different species

of the genus Testudo in the Mediterranean and Asia

Minor (Lambert, 1979). In the latter case, the consoli-

dation of the pet trade during the 19th century led to an

international export trade involving thousands of cir-

cum-Mediterranean species per year and which include

Testudo hermanni from the Balkans, T. horsfieldii fromthe southwest of the former Soviet Union, T. graeca

ibera from Turkey and T. graeca graeca from Morocco

(Lambert, 1979).

In Spain, this trade has never reached international

proportions, although a regular national trade existed

within the natural range of the species (T. graeca gra-

eca comes from southeast Spain and T. hermanni from

the Balearic islands) (Fig. 1) towards urban centressuch as Madrid and Barcelona (L�opez-Jurado et al.,

1979).

T. graeca graeca – commonly named the spur-thighed

tortoise – is one of six subspecies of T. graeca native to

the Mediterranean and Asia Minor (Iverson, 1992;

Gmira, 1993; David, 1994). It is distributed throughout

North Africa, from the Atlantic coast of Morocco to

Northeast Libya, and in small patches in the Do~nanaBiological Reserve (southwest Spain), Mallorca and

parts of southeast Spain (provinces of Murcia and Al-

mer�ıa) (Andreu and L�opez-Jurado, 1998) (Fig. 1a and

b). The main population of T. graeca graeca in Europe

inhabits semiarid coastal mountains on metamorphic

substrates in southeast Spain. Annual precipitation here

ranges from 214 to 351 mm and vegetation cover con-

sists basically of sparse scrub with small patches of openPinus halepensis and Quercus rotundifolia woodland and

dry farming (Gim�enez et al., 2001). This tortoise has a

high international, national and local protection status.

It is included in Appendix II of the Convention on In-

ternational Trade in Endangered Species (http://

www.cites.org), in Appendix II of the Bern Convention

(http://www.nature.coe.int/english/cadres/bern.htm) and

is classified as vulnerable in the IUCN Red List of

Threatened Species (IUCN, 2002). In the European

Union the species is inluded in Appendix II and IV of

the Habitat Directive (http://www.europa.eu.int/comm/

environment/nature/themes.htm) and �243,000 ha of its

habitat has been proposed for inclusion in the Natura

2000 network, while in Spain this tortoise is considered

as being endangered (Pleguezuelos et al., 2002).

Although it is illegal to collect or to sell this speciesof tortoise, in southeast Spain the custom exists of

keeping tortoises in captivity and large numbers of

tortoises are collected from wild populations. This ac-

tivity seems to be a very common custom in many local

cultures and also threatens other species of endangered

terrestrial tortoises (L�opez-Jurado et al., 1979; Curl

et al., 1985; Fritts and Jennings, 1994; Waller, 1997;

Pujol, 1998). However, this collection on a local scalewith no commercial objectives in mind has not been

diagnosed as a possible threat in most cases. The

present study aims to: (i) describe the collection of

T. graeca graeca in southeast Spain, (ii) calculate the

numbers of animals kept in captivity, and (iii) deter-

mine the implications of this process on the conserva-

tion of the species, and thereby carry out a critical

review of the conservation strategies developed inconnection with this conservation issue.

2. Methods

In order to address the objectives of this study, we

carried out surveys of children in schools, given the easy

accessibility to this sector of the population, and becausewe considered them to be an important part of those

who keep tortoises as pets.

We made 796 interviews of school children, mainly

between the ages of 12 and 15 (87% of pupils inter-

viewed) (Fig. 2). Surveys were carried out in all the

districts of the province of Murcia within the distribu-

tion area of T. graeca graeca, as well as in five peripheral

districts (Fig. 1c, Table 1). All rural schools and a rep-

Fig. 2. Frequency distribution of age of the children polled.

I. P�erez et al. / Biological Conservation 118 (2004) 175–181 177

resentative sample of urban schools were surveyed,

which in total amounted to 26 schools in 22 towns and

cities.

The surveys were conducted in the classroom by a

person with experience in environmental education and

consisted of seven open questions: whether pupils had or

had had tortoises in captivity as pets, the number of

captive tortoises, their origin and the way they wereobtained, the destination of these tortoises if they had

got rid of them, and whether they had bred. The chil-

dren were also asked their ages and addresses.

Children were classified as rural or urban inhabitants,

taking rural to mean from villages with less than 250

inhabitants. Also, children were distinguished as living

inside or outside the distribution range of T. graeca

graeca.We performed an independent test (v2, significance at

5% level) to study the relationship between answers and

these two characteristics of the children. If the null hy-

Table 1

Number of surveys made per district and representation of the school age

Estad�ıstica de Murcia, 1991)

District Location Number of interview

Aledo Outside 17

Alhama Outside 11�Aguilas Inside 259

Cartagena Outside 106

Lorca Inside 187

Fuente �Alamo Outside 74

Mazarr�on Inside 23

Murcia Outside 37

Puerto Lumbreras Inside 64

Totana Outside 18

Total 796

Inside, districts inside the distribution area of the species; outside, district

pothesis was rejected, the contingency coefficient (C) wascalculated. This coefficient varied between 0 (no associ-

ation) and the maximum association valuepððq� 1Þ=qÞ,

where q was the minimum number of rows or columns of

the contingency table. In our case, the number of rowsand columns was always two, and so the maximum

contingency coefficient was 0.71.

For each question, responses were described by their

proportion within the sample and by their confidence

interval (CI). CI was calculated using the normal ap-

proximation method (significance at 5% level) (Zar,

1984). We have indicated the partial and global values

when there was a significant difference in the differentcategories of the variables.

Regarding the question of the number of captive

tortoises per person, we utilised the Mann–Whitney test

in order to show if there were statistical differences be-

tween the mean number of tortoises in the different

categories of children. We have indicated the CI for the

population mean (significance at 5% level).

On the basis of the proportion of children with cap-tive tortoises and the mean number of captive tortoises

per child, we estimated the number of tortoises kept in

captivity in the study area. We made this estimation

using only 13-year-old children (the most frequent age in

our sample) to avoid double counting of families with

children of similar ages. For this estimate we did not

take into consideration the survey carried out in the city

of Murcia (Table 1), since we considered that it is notrepresentative of the district as a whole. In the results,

we have indicated the CI for the population mean (sig-

nificance at 5% level).

3. Results

3.1. Quantification of captivity

The mean proportion of children that had or had

had a tortoise in captivity was 64.5%. For CIs see

population (between 7 and 19 years old) polled (Centro Regional de

s Population (7–19 years old) Polled population (%)

134 12.60

2578 0.42

5313 4.87

31,988 0.33

12,366 1.51

1393 5.31

3177 0.72

63,366 0.05

1782 3.59

3274 0.54

125,371 0.63

s in the periphery of the distribution area of the species.

178 I. P�erez et al. / Biological Conservation 118 (2004) 175–181

Table 2. This proportion was significantly higher in the

districts inside the distribution area of the species than

in the districts outside of the distribution area

(v2 ¼ 27:81; df¼ 1; P < 0:001; C ¼ 0:18). Inside, the

mean proportion of children with tortoises was 70.5%,while in the periphery it was 51.5%. The proportion of

children that had or had had a tortoise in captivity is

also higher in urban schools (v2 ¼ 5:44; df¼ 1;

P < 0:02; C ¼ 0:08). The mean proportion of urban

children with tortoises was 69%, while in rural areas it

was 61.5%.

Of those children that had or had had tortoises,

nearly three-quarters (71%) had only one or two but afew had much larger numbers (6% had 10 or more). The

mean number of captive tortoises per child for the whole

study area was 2.9. Mean value was significantly higher

in districts inside the distribution area of the species than

in the peripheral districts (U ¼ 3:33; P < 0:001) (Table2). However, there were no significant differences

between rural and urban populations (U ¼ 1:208;P > 0:05).

3.2. Origin, captive breeding and destination of captive

tortoises

On average, only 7.5% of children had bought their

tortoise, 63.5%hadobtained them fromwild populations,

directly or through somebody else, and the remaining

29% did not know the origin of their tortoise (CI in Table2). Inside the distribution area, 74.5% of the children had

obtained their tortoises from wild populations, while in

peripheral districts the mean proportion fell to 37.5%

(v2 ¼ 60:26; df¼ 1; P < 0:001; C ¼ 0:32). Again, within

Table 2

Results of the surveys in the study area, inside and outside the distribution

n Whole area Inside O

Captive tortoises (%) 796 61–68 67–74 4

Tortoises per person 513 2.5–3.4 2.8–3.9 1

Origin 513

Wild population (%) 60–68 71–78 2

Trade (%) 5–10 1–5 1

Middleman (%) 25–33 21–30 3

Captive breeding (%) 513 14–22 – –

Destination 306

Release (%) 12–18 14–22

Transfer (%) 10–15 8–14 1

Lost (%) 11–17 – –

Died (%) 14–20 18–33 1

Organization (%) 1–4 0.3–3

n.s.¼not significant.

CIs for percentage of children that have tortoises in captivity, the mean nu

and captive breeding.* P < 0:05.

** P < 0:01.*** P < 0:001.

the distribution area, only 3% of children had bought

their tortoises compared to 21% outside the area

(v2 ¼ 60:26; df¼ 1; P < 0:001;C ¼ 0:29). The proportionof tortoises transferred by another person who did not

know the origin of the tortoise was higher in peripheraldistricts (39.5%) than districts inside the distribution area

(25.5%) (v2 ¼ 9:80; df¼ 1; P < 0:01; C ¼ 0:14).In relation to captive breeding, 18% of the children

had had tortoises that bred in captivity. There were no

differences either between core and peripheral districts

(v2 ¼ 2:00; df¼ 1; P < 0:05) or between the urban and

rural schools (v2 ¼ 3:07; df¼ 1; P > 0:05).With regards to the destination of the captive tor-

toises, 15% of the children answered that they had re-

introduced their tortoises into the wild, 12.5% had given

their tortoises to another person, 14% had lost their

tortoises and only 2.5% had donated their tortoises to

organisations or wildlife protection institutions. Finally,

17% of the children answered that their captive tortoise

had died. In comparing core and peripheral districts,

there were significant differences between children withinand outside the core areas for the proportions released

in the wild (v2 ¼ 10:15; df¼ 1; P < 0:01; C ¼ 0:14),those dying in captivity (v2 ¼ 8:5; df¼ 1; P < 0:01;C ¼ 0:13) and those donated to organisations or wildlife

protection institutions (v2 ¼ 5:87; df¼ 1; P < 0:05;C ¼ 0:11) (Table 2).

3.3. Captive population estimation

For the subsample of 13-year-old children surveyed,

there were even larger differences than in the whole

sample between schools inside and outside the species�

area of T. graeca graeca for rural and urban schools

utside P Urban Rural P

5–58 ��� 64–74 57–66 �

.7–2.7 ��� – – n.s.

– –

9–46 ��� n.s.

4–28 ��� – – n.s.

1–48 �� n.s.

n.s. – – n.s.

3–12 �� – – n.s.

0–15 n.s. – – n.s.

– – – –

1–18 �� – – n.s.

2–10 n.s. – – n.s.

mber of tortoises per child, the origin and destination of these tortoises

Table 3

CIs estimates of the captive tortoise populations in the study area

Inside Outside P Study area

Captive tortoises (%) 63–77 44–65 � –

Tortoises per person 3–6 1–4 � –

13 years old population 1734 2982 4716

Number of families 29,796 55,143 84,939

Estimate a 3527–7565 1711–7051 5237–14,617

Estimate b 60,600-129,994 31,631–13,0378 92,231–260,373

(a) Number of tortoises in the subpopulation of 13-year-old children. (b) Number of tortoises in all families in the study area.* P < 0:05.

I. P�erez et al. / Biological Conservation 118 (2004) 175–181 179

range; this applies to the proportions having captive

tortoises (v2 ¼ 6:54; df¼ 1; P < 0:05), and for the

numbers kept per child (U ¼ 1:971; P < 0:05), (thoughthe levels of significance were lower because of the

smaller numbers sampled – Table 3).The total number of families having a 13-year-old

child in the whole sample was 1734 (Centro Regional de

Estad�ıstica de Murcia, 1991) from which we estimate

that the total number of captive tortoises in the whole

study area was �10,000, with very wide confidence

limits (Table 3). The extrapolation of this estimate to all

families (instead of just the 5.5% that had a 13-year-old;

Centro Regional de Estad�ıstica de Murcia, 1991) leadsto a total figure of about 176,000 with confidence limits

of 92,231–260,373 (Table 3). However, this is certain to

be an overestimate since we know that families without

children of school age are less likely to have tortoises.

Overall, we therefore consider that the number of tor-

toises kept in captivity in the study area is in the order of

tens of thousands.

4. Discussion

4.1. Captivity and collection process

Our results reveal that, at present, the capture of

T. graeca graeca for trade is a marginal issue in

southeastern Spain. This contradicts recent local and

national reviews concerning the conservation status of

this tortoise (Castanedo et al., 1991; Blanco and

Gonz�alez, 1992; Blasco, 1992; Andreu and L�opez-Jurado, 1998; Garc�ıa, 1999), in which trade was iden-tified as one of the main threats facing the species in

this area. These studies probably reflect a past situa-

tion, when locally collected animals were more widely

sold in markets and pet shops both here and in other

geographical areas in Spain where wild tortoises do not

occur (L�opez-Jurado et al., 1979). In those other parts

of Spain, the demand for tortoises may be supplied at

present by animals from North Africa, where com-merce and export are still common activities (Dupre,

2002; Ferr�andez, 2003).

However, in southeast Spain the custom of keeping

tortoises in captivity is still very common. The estimate

of tens of thousand of animals is an indication of its

magnitude but there is a need to carry out more precise

studies to refine these figures. The way most tortoisesreach captivity is by direct collection from wild popu-

lations through chance encounters by local inhabitants,

and not through active search for the species with

commercial objectives in mind. This is mainly a local

activity, since the proportion of people who have

captive tortoises and the number of captive tortoises

per person decreases considerably from within the

distribution range of the species to the peripheral area.There is quite an important stock of tortoises that

breed in captivity, and a significant flow of tortoises

from one person to another, but few individuals

are donated to organisations or wildlife protection

institutions.

The custom of keeping tortoises in captivity is

maintained by popular belief regarding its benefits and,

above all, by their attraction to children as pets. Thiscustom was firmly rooted in rural areas before being

exported to urban centres by street sellers. At present,

through notable rural depopulation and the develop-

ment of legislation concerning the conservation of wild

animals, the regular collection and trade in tortoises has

gradually declined.

4.2. Implications for conservation

The high proportion of people who collect tortoises

from wild populations suggests that this disturbance of

T. graeca graeca populations may have demographicconsequences which may include local extinction in

areas around villages. Furthermore, the release of cap-

tive tortoises into the wild without any institutional

control may also severely affect established populations

by disease transmission (Dodd and Seigel, 1991; Jac-

obson, 1993; Cunningham, 1996; Deem et al., 2001).

This has been suggested as the prime agent in the

rapid decline of some populations of desert tortoise(Gopherus agassizii) in the western Mojave Desert where

180 I. P�erez et al. / Biological Conservation 118 (2004) 175–181

individuals suffering from the upper respiratory disease

syndrome (URSD) were released (Jacobson, 1993;

Brown et al., 1994; Jacobson et al., 1995). There is also

the possibility of creating outbreeding depression, that

is, a decline in fitness associated with mating amonggenetically distinct populations (Templeton, 1994; Seigel

and Dodd, 2000).

Conservation strategies for T. graeca graeca have

focussed on the control of trade in the species and on re-

introduction programmes of captive tortoises. In the

first case, national and international strategies designed

to combat pet traffic have been essential in the past and

in Spain have almost ended the trade in tortoises. In thesecond case, re-introductions seem irrelevant when

compared to threats such as habitat destruction

(Gim�enez et al., 2001) and continued chance collection.

Besides, the effectiveness of these techniques of manip-

ulation, especially in reptiles, are debatable (Dodd and

Seigel, 1991; Wolf et al., 1996; Seigel and Dodd, 2000)

and need significant economic and human resources

(Griffith et al., 1989; Lindbeurg, 1992; Kleiman et al.,1994). There is a predisposition to use re-introductions

as a quick and easy solution to complex conservation

issues rather than tackling the real causes of population

declines (Dodd and Seigel, 1991; Fischer and Linden-

mayer, 2000).

4.3. Conservation recommendations

There is a social perception of the spur-thighed tor-

toise as a pet, which reveals lack of popular knowledge

about its legal situation, the threatened status of the

species and its place as a typical element of semiarid

landscapes of southeast Spain. All of this implies a need

to develop environmental education programmes to-

wards a perception of the tortoise as a wild animal. T.

graeca graeca inhabits arid and semiarid areas of highecological value, but the local inhabitants and general

public do not appreciate the worth of these landscapes.

At present these systems are strongly threatened, mainly

by irrigated farming and urban development (Mart�ınez,2001; Gim�enez et al., 2001). TheNatura 2000 programme

is an important policy for conserving European biodi-

versity and, in particular, for preserving the habitat of T.

graeca graeca in Spain. The spur-thighed tortoise couldbe promoted as a flagship species (Caro and O�Doherty,

1999) to help safeguard these semiarid ecosystems.

Acknowledgements

We wish to thank Rosa Pardo for carrying out the

surveys and Dr. Kaldo for his comments and statisticalassistance. Financial support was provided by the

Consejer�ıa de Agricultura, Agua y Medio Ambiente de

la Regi�on de Murcia. We also thank Dr. B.N.K. Davis

and an anonymous reviewer for their suggestions on the

manuscript.

References

Andreu, A.C., 1988. Las poblaciones naturales de tortuga mora

(Testudo graeca graeca) en el sureste peninsular. Instituto de

estudios almerienses. Diputaci�on Provincial de Almer�ıa.

Andreu, A.C., L�opez-Jurado, L.F., 1998. Los reptiles ib�ericos: g�enero

Testudo. In: Ramos, M.A. et al. (Eds.), Fauna Ib�erica. Reptiles.

Museo Nacional de Ciencias Naturales, CSIC, Madrid.

Blanco, J.C., Gonz�alez, J.L., 1992. Libro rojo de los vertebrados de

Espa~na. Ministerio de Agricultura, pesca y Alimentaci�on. Cole-

cci�on t�ecnica, ICONA, Madrid.

Blasco, M., 1992. La tortuga mora (Testudo graeca L.) en el sureste de

la Pen�ınsula Ib�erica. Datos para su conservaci�on. II Congreso

Luso-espa~nol y IV Congreso Espa~nol de Herpetolog�ıa, Granada.

Brown, M.B., Schumacher, I.M., Klein, P.A., Harris, K., Correll, T.,

Jacobson, E.R., 1994. Mycoplasma agassizii causes upper respira-

tory tract disease in the desert tortoise. Infection and Immunity 62,

4580–4586.

Buskirk, J.R., 1993. Distribution, status and biology of the tortoise,

Geochelone chilensis, in R�ıo Negro Province, Argentina. Studies on

Neotropical Fauna and Environment 2 (4), 233–249.

Caro, T.M., O�Doherty, G., 1999. On the use of surrogate species in

conservation biology. Conservation Biology 13, 805–814.

Castanedo, J.L., Cano, A.J., Ib�a~nez, J.M., 1991. Conservaci�on de la

tortuga mora en Murcia. Quercus 70, 22–24.

Caughley, G., Gunn, A., 1996. Conservation Biology in Theory and

Practice. Blackwell Scientific Publications, Cambridge, MA.

Centro Regional de Estad�ıstica de Murcia, 1991. Censo de poblaci�on

de 1991 de la Regi�on de Murcia. Consejer�ıa de Fomento y Trabajo,

Murcia.

Chan, E.H., Liew, H.C., Mazlan, A.G., 1988. The incidental capture of

sea turtles in fishing gear in Teregganu, Malaysia. Biological

Conservation 43, 1–7.

Christian, C.S., Lacher, T.E., Zamore, M.P., Potts, T.D., Burnett,

G.W., 1996. Parrot conservation in the lesser antilles with some

comparison to the Puerto Rican efforts. Biological Conservation

77, 159–167.

Cunningham, A.A., 1996. Disease risks of wildlife translocations.

Conservation Biology 10, 349–353.

Curl, D.A., Scoones, I.C., Guy, M.K., Rakotoarisoa, G., 1985. The

Madagascan tortoise Geochelone yniphora: Current status and

distribution. Biological Conservation 34, 35–54.

David, P., 1994. Liste des reptiles actuels du monde I. Chelonii.

Dumerilia 1, 7–127.

Deem, S.L., Karesh, W.B., Weisman, W., 2001. Putting theory into

practice: wildlife health in conservation. Conservation Biology 15,

1224–1233.

Dodd Jr., C.K., Seigel, R.A., 1991. Relocation, repatriation and

translocation of amphibians and reptiles: are they conservation

strategies that work? Herpetologica 47, 336–350.

Dupre, A., 2002. Situation de Testudo graeca au Maghreb. Chelonii 3,

300–301.

Ferr�andez, M., 2003. Illegal trade of Greek tortoise (Testudo graeca)

coming from Algeria admitted in the Wildlife Preservation Centre

Santa Faz Alicante (Spain). Second International Congress on

Chelonian Conservation, Senegal.

Fischer, J., Lindenmayer, D.B., 2000. An assessment of the published

results of animal relocations. Biological Conservation 96, 1–11.

Fitzgerald, L.A., Cruz, F.B., Perotti, G., 1993. The reproductive

cycle and the size at maturity of Tupinambis rufescens (Sauria:

teiidae) in the dry Chaco of Argentina. Journal of Herpetology

27, 70–78.

I. P�erez et al. / Biological Conservation 118 (2004) 175–181 181

Fritts, T.H., Jennings, R.D., 1994. Distribution, habitat use and status

of the tortoise in Mexico. In: Bury, R.B., Germano, D.J. (Eds.),

Biology of North American Tortoises. National Biological Survey,

Washington, D.C., pp. 48–56.

Garc�ıa, P., 1999. La tortuga mora a salvo en Cartagena. La tierra 14,

43–47.

Gim�enez, A., Esteve, M.A., Anad�on, J.D., Mart�ınez, J., Mart�ınez, M.,

P�erez, I., 2001. Estudios b�asicos para una estrategia de conser-

vaci�on de la tortuga mora en la Regi�on de Murcia. Consejer�ıa de

Agricultura, Agua y Medio Ambiente, Unpublished.

Gmira, S., 1993. Nouvelles donn�ees sur les esp�eces actuelles de Testudo(Chelonii, Testudinidae). Bulletin de la Soci�et�e Herp�etologique de

France 65–66, 49–56.

Griffith, B., Scott, J.M., Carpenter, J.W., Reed, C., 1989. Transloca-

tion as a species conservation tool: status and strategy. Science 245,

477–480.

Hemley, G., Mills, J.A., 1999. The beginning of the end of tigers in

trade? In: Seidensticher, J., Christie, S., Jackson, P. (Eds.), Riding

the Tiger. Tiger Conservation in Human-Dominated Landscapes.

Cambridge University Press, UK, pp. 217–229.

Honneger, R.E., 1981. List of amphibians and reptiles either known or

throught to have become extinct since 1600. Biological Conserva-

tion 19, 141–158.

IUCN/Species Survival Commission. 2002. IUCN Red List of

Threatened Species. Gland, Switzerland.

Iverson, J.B., 1992. A revised checklist with distribution maps of the

turtles of the world. Private printing, Richmond.

Jacobson, E.R., 1993. Implications of infectious diseases for captive

propagation and introduction programs of threatened/endangered

reptiles. Journal of Zoo and Wildlife Medicine 24, 245–255.

Jacobson, E.R., Brown, M.B., Schumacher, I.M., Collins, B.R.,

Harris, R.K., Klein, P.A., 1995. Mycoplasmosis and the desert

tortoise (Gopherus agassizii) in Las Vegas valley. Nevada 1, 279–

284.

Kleiman, D.G., Price, M.R.S., Beck, B.B., 1994. Criteria for reintro-

ductions. In: Onley, P.J.S., Mace, G.M., Feistner, A.G.C. (Eds.),

Creative Conservation: Interactive Management of Wild and

Captive Animals. Chapman and Hall, London, UK, pp. 164–184.

Klemens, M.W., Thorbjarnarson, J.B., 1995. Reptiles as a food

resource. Biodiversity and Conservation 4, 218–298.

Lambert, M.R.K., 1979. Trade and the mediterranean tortoises. Oryx

15, 81–82.

Lindbeurg, D.G., 1992. Are wildlife reintroductions worth the cost?

Zoo Biology 11, 1–2.

L�opez-Jurado, L.F., Talavera Torralba, P.A., Ib�a~nez Gonzalez, J.M.,

MacIvor, J.A., Garc�ıa Alcaraz, A., 1979. Las tortugas terrestres

Testudo graeca y Testudo hermanni en Espa~na. Naturalia Hispanica

17, 1–63.

Mart�ınez, J., 2001. Modelos de simulaci�on din�amica en el estudio de

las externalidades ambientales del regad�ıo en sistemas �aridos y

semi�aridos del sistema ib�erico. PhD Thesis, Universidad de Murcia.

Milner-Gulland, E.J., Mace, R., 1991. The impact of the ivory trade on

the african elephant Loxodonta africana population as assessed by

data from the trade. Biological Conservation 55, 215–229.

Pleguezuelos, J.M., M�arquez, R., Lizana, M., 2002. Atlas y libro rojo

de los anfibios y reptiles de Espa~na. Direcci�on General de la

Conservaci�on de la Naturaleza. Asociaci�on Herpetol�ogica

Espa~nola, Madrid.

Pujol, J.A., 1998. Las tortugas terrestres de zonas �aridas de la

Rep�ublica Argentina: ecolog�ıa y principales amenazas. Ciencia

Hoy 8, 38–46.

Seigel, R.A., Dodd Jr., C.K., 2000. Manipulation of turtle populations

for conservation. Halfway technologies of Viable Options? In:

Klemens, M.W. (Ed.), Turtle Conservation. Smithsonian Institu-

tion Press, Washington and London.

Shine, R., Harlow, P.S., Deogh, J.S., 1996. Commercial harvesting of

giant lizards: the biology of water monitors Varanus salvator in

Southern Sumatra. Biological Conservation 77, 125–134.

Tchamba, M.N., 1996. History and present status of the human/

elephant conflict in the Waza-Logone region, Cameroon, West

Africa. Biological Conservation 75, 35–41.

Templeton, A.R., 1994. Coadaptation, local adaptation and outbreed-

ing depression. In: Meffe, G.K., Carroll, R.K. (Eds.), Principles of

Conservation Biology. Sinauer, Sunderland, MA, pp. 152–153.

Thorbjarnarson, J., Lagueux, C.J., Bolze, D., Klemens, M.W.,

Meylan, A.B., 2000. Human use of turtles: a worldwide perspective.

In: Klemens, M.W. (Ed.), Turtle Conservation. Smithsonian

Institution Press, Washington and London.

Waller, T., 1997. Exploitation and trade of Geochelone chilensis. In:

Van Abbema, J. (Ed.), Proceedings: Conservation, Restoration and

Management of tortoises and turtles-an International Conference,

July 1993, State University of New York at Purchase. Turtle and

Tortoise Society, New York, pp. 118–124.

Wolf, C.M., Griffith, B., Reed, C., Temple, S.A., 1996. Avian and

mammalian translocations: update and reanalysis of 1987 survey

data. Conservation Biology 10, 1142–1154.

Zar, J.H., 1984. Biostatistical Analysis. Prentice Hall, Englewood

Cliffs, NJ.