Secret lives of maned wolves (Chrysocyon brachyurus Illiger1815): as revealed by GPS tracking collars

L. F. Bandeira de Melo1, M. A. Lima Sabato1, E. M. Vaz Magni1, R. J. Young2 & C. M. Coelho1

1 Fundacao Zoo-Botanica, Belo Horizonte, Minas Gerais, Brazil

2 Conservation, Ecology and Animal Behaviour Group, Mestrado em Zoologia, Pontifıca Universidade Catolica de Minas Gerais, Belo Horizonte,

Minas Gerais, Brazil

Keywords

Chrysocyon brachyurus; maned wolves; GPS

collar; socio-spatial dynamics; home range.

Correspondence

Robert John Young, Conservation, Ecology

and Animal Behaviour Group, Predio 41,

Mestrado em Zoologia, Pontifıca

Universidade Catolica de Minas Gerais, Av.

Dom Jose Gaspar, 500 Coracao Eucarıstico,

30535-610 Belo Horizonte, Minas Gerais,

Brazil. Tel: +55 31 3319 4936;

Fax: +55 31 3319 4938

Email: robyoung@pucminas.br

Received 20 December 2005; accepted

11 April 2006

doi:10.1111/j.1469-7998.2006.00176.x

Abstract

The maned wolf Chrysocyon brachyurus is a nocturnal and shy species, which has

proven difficult to study in the field; consequently, data about its behavioural

biology are almost absent from the scientific literature. However, recent advances

in global positioning system (GPS) technology mean that it is now possible to

study the socio-spatial dynamics of this species in the field. In the present study

three related maned wolves (an adult pair and their juvenile female offspring) were

monitored by GPS tracking collars for a 6-month period, which included the birth

of a litter of pups to the adult pair. The three GPS collars were programmed to

record the position of the wearer every 2 h (simultaneously for all three indivi-

duals). Analyses of the data from the three individuals showed that the female had

the largest home range, then the male and finally the juvenile. Furthermore, there

was considerable overlap in home-range use by all three individuals. The home

ranges of the adult pair also varied in relation to the birth of pups (decreasing

dramatically and then showing a slow increase). During the night, which is the

normal period of activity for this species, the three individuals avoided contact

with each other. However, during the day, the adult pair usually slept together and

their juvenile slept within a few hundred metres of their location. The distance

travelled at night was greatest for the female, then the male and finally the juvenile.

These data suggest that (1) the social bond between the male and female is strong,

(2) maned wolves are highly tolerant of their juvenile offspring, even in the case of

new pups being born, and (3) that maned wolves do not hunt together and, in fact,

avoid each other when hunting.

Introduction

The maned wolf Chrysocyon brachyurus is the largest South

American canid with a wide distribution in the savannas

of Latin America. Despite being a characteristic species of

the Brazilian cerrado (savanna environment), relatively

little is known about the behavioural biology of this

species. The classic field study on the biology of the maned

wolf by Dietz (1984) is now more than 20 years old, and

arguably our knowledge about the wild behaviour

of this species has not increased greatly since this study.

The study by Dietz (1984) was based on a mixture of

methodologies, including radio-tracking, collection of

faeces and interviews with local people. Unfortunately,

much of the data we have on the species’ social and

reproductive behaviours comes from interviews of local

people and not from quantitative studies. Our lack of

knowledge concerning these aspects of the natural history

of maned wolves results largely from their secretive and

nocturnal habits.

The few field studies that have been published on maned

wolves have largely concentrated on analysing the species’

diet (i.e. trophic ecology; Dietz, 1984; Motta-Junior et al.,

1996; Motta-Junior, 2000; Bueno, Belentani & Motta-

Junior, 2002; Motta-Junior & Martins, 2002) owing to the

ease with which faeces can be collected (maned wolf faeces

have a strong and pungent odour), or have captured maned

wolves to investigate their health status (e.g. Carvalho &

Vasconcellos, 1995). Recently, Silva & Talamoni (2004)

tried to investigate the centre of activity of maned wolves in

the field from their defecation sites and tracks, and a few

authors have attempted to estimate the species’ home range

using radio-tracking studies (e.g. Dietz, 1984). Behavioural

studies of maned wolves have been restricted to captive

studies, for example studies on parental behaviour (Veado,

1997) and reproductive behaviour (Dietz, 1984). The field-

work conducted by Dietz (1984) has been hugely influential

in promoting the hypothesis that maned wolves are nor-

mally solitary animals, which come together only for repro-

duction. However, this conclusion is based on almost no

Journal of Zoology 271 (2007) 27–36 c� 2006 The Authors. Journal compilation c� 2006 The Zoological Society of London 27

Journal of Zoology. Print ISSN 0952-8369

observational data, and captive studies, including that

conducted by Dietz (1984), have suggested a reasonably

high level of sociability, for example male provisioning

of food to pups (Dietz, 1984; Rasmussen & Tilson, 1984;

Veado, 1997).

The maned wolf is presently listed as ‘near threatened’ in

the IUCN’s Red List of 2004 (Sillero-Zubiri & Hoffmann,

2004), and this classification is based largely on population

sizes and not on an in-depth understanding of the species’

biology. Therefore, presently in Brazil the maned wolf is

increasingly being studied both in situ and ex situ owing to

our lack of knowledge about this species and its potential as

a flagship or umbrella species.

Classically, large mammal species with secretive and/or

nocturnal habits have been studied in the wild with the

aid of radio-telemetry devices. However, such devices

have a number of limitations, for example the need to

triangulate the position of the animal (Saltz, 1994)

and the risk of disturbing the animal. In a species

such as the maned wolf, which when active is constantly

in rapid locomotion, the process of triangulation to

locate the animal is not only difficult but also relat-

ively inaccurate (Samuel & Fuller, 1994; Theuerkauf &

Jedrzejewski, 2002). Other methods of assessing areas

of spatial activity have been attempted using location

of faeces and tracks, and the marking of collection

points with a global positioning system (GPS) device

(Silva & Talamoni, 2004). Recently, GPS technology

has advanced to the point where GPS devices can be

included in the collars placed on wild animals (Rutter,

Beresford & Roberts, 1997; Blake, Douglas-

Hamilton & Karesh, 2001; McCarthy et al., 2005) and

thereby allow tracking. If GPS collars are placed

on several individuals of the same social group, it

becomes possible to measure group socio-spatial

dynamics. The spatial distribution of individuals of a

species can reveal interesting information about the

species’ social organization. For example, a number of

authors have asserted that the maned wolf is monogamous

and territorial, but this is based on fortuitous (ad hoc)

field observations and radio-telemetry studies (e.g. Dietz,

1984, 1985).

Although ad hoc field observations of maned wolves can

be helpful in understanding this species, these are frequently

limited to daylight hours (e.g. Dietz, 1984). A number of

species show temporal variation in their expression of social

behaviour. The classic example is the domestic cat Felis

catus, which during its period of inactivity, daylight hours,

often does not seek the company of conspecifics. However,

at night, during its period of activity, it seeks encounters

with conspecifics and can, under certain environmental

conditions, be highly social (Crowell-Davis, Curtis &

Knowles, 2004).

In this paper we report the spatial relationships and home

range of three related maned wolves (an adult pair and

a juvenile female), all monitored simultaneously by GPS

collars before and after the adult pair produced a litter

of pups.

Methods

Animals

The subjects of this study were three wild maned wolves

C. brachyurus: one adult female, one adult male (both of

unknown ages) and one juvenile female (estimated to be

1 year old, not sexually mature and assumed to be

the offspring of the adult male pair). Before the start of

the study, beginning the wolves were captured using a

wooden trap as described by Dietz (1984); the male

was caught on 7 May 2003, the female on 8 May 2003 and

the juvenile on 26 February 2003. The use of this type of trap

is considered a humane way of capturing wild maned

wolves.

Immediately after being captured, each maned wolf was

anaesthetized by a qualified veterinary surgeon, who then

clinically examined the health status of the individual

(e.g. presence of skin parasites), and biometric measure-

ments were taken. Following this a GPS radio-transmitting

collar (see below) was placed on the individual, the animal

was then allowed to recover from the anaesthesia and, when

the veterinary surgeon considered the animal to have fully

recovered, it was released. At the end of the study the

subjects were recaptured to have their collar removed or

the battery changed.

Study site

Our study was conducted at the Galheiros Reserve [RPPN

Estacao Ambiental de Galheiro, which is a private nature

reserve belonging to and managed by CEMIG (Companhia

Energetica de Minas Gerais)] in Perdizes, in the west of

Minas Gerais State, Brazil. The reserve has an area of

2847 ha and is largely a cerrado (Brazilian savanna) habitat

with some Atlantic rainforest influence. The reserve undu-

lates substantially with minimum altitudes of 815m and

maximum altitudes of 929m. The vegetation can be mainly

classified as cerrado fields or dense cerrado shrubland; there

is also some gallery forest within the reserve. The low-

altitude section of the reserve is comprised of forests and an

artificial reservoir that provides water for Nova Ponte

hydro-electricity station. The reserve is well protected from

illegal environmental exploitation, such as hunting. It can be

considered an ‘island’ of natural habitat, because it is

completely surrounded by farmland where soya beans are

grown and cattle are raised. Inside the reserve are a number

of administrative buildings and a visitor centre, which

provides environmental education opportunities for the

schools of the region.

The study was conducted in the dry season from

the month of May to October, with total rainfall for

this period usually having a mean value of less than 30mm.

During this season in the cerrado, food in the form of

small rodents is considered to be more abundant than

in the wet season (Dietz, 1984; Alho, Pereira & Paula,

1986).

Journal of Zoology 271 (2007) 27–36 c� 2006 The Authors. Journal compilation c� 2006 The Zoological Society of London28

The secret lives of maned wolves L. F. Bandeira de Melo et al.

GPS collar

The GPS collar was model ‘GPS-Simplex’ manufactured by

TELEVILT (Sweden) and had a total weight of 700 g, which

corresponds to c. 2% of the body weight of an adult maned

wolf. This type of telemetry device permits two types of data

collection: (1) the manual use of a receiver (RX-900; Tele-

vilt, Lindesberg, Sweden) to locate the wearer in the classic

manner of radio-telemetry studies (i.e. through triangula-

tion) and (2) the automatic storage of satellite position data

(i.e. GPS coordinates of the wearer), which can be subse-

quently downloaded by radio transmission to a receiver in

the field (when within a few kilometres of the animal’s

location) for subsequent analysis (using the software ‘Sim-

plex Project Manager V 1.2.5’). The data reported in this

study were collected using only the second method. The

collar of each animal was programmed to store the wearer’s

geographical coordinates every 2 h (1, 3, 5 until 23 h) during

the life of the battery (until 11 October 2003 in the case of

the male and female). Once a month during the field study,

the field biologists downloaded the data to the receiver. The

GPS collars provided us with the identity of the wearer, its

geographical location (hours, minutes and seconds, later

converted to UTM format by the management software),

and the date and time when location was recorded. Unfor-

tunately, if the wearer of the collar was in dense under-

growth the GPS device was not able to locate itself and,

therefore, the data do not correspond perfectly to the

number of days of the study multiplied by 12 two-hourly

data points (see Results).

Field study

During the study period fromApril 2003 to the present date,

two biologists made monthly visits to the study area to

download the GPS data and to collect other information

concerning the biology of maned wolves. For example,

camera trapping was used to detect the presence of large

predators, along with other species in the reserve, and to

observe the movement of the maned wolves, especially with

their pups. Maned wolves were not radio-tracked during

these field campaigns to avoid disturbance of their natural

behaviour.

Data analysis

The data used in this article only pertain to the period when

all three GPS collars were functioning, which was from

8 May 2003 to 11 October 2003, as we wish to analyse the

social spatial dynamics of the three related individuals. To

calculate sizes of home ranges and distances moved, we used

all the data available for the adult female (1668 fixes), adult

male (1676) and juvenile female (1553). To calculate spatial

relationships between individuals, we used only data when

the three GPS collars recorded the three individuals on the

same day at the same time (total number of fixes=1502).

Although we did not test the accuracy of our GPS collars,

a recent study has reviewed the accuracy of consumer-grade

GPS devices and found them to have a mean accuracy of 5m

in open habitats and a maximum error of 15m (Wing,

Eklund & Kellogg, 2005).

The home-range areas and their areas of overlap were

calculated using the software ‘Biota 1.03 alpha’. The dis-

tances between individuals and their movement between

fixes were calculated in Microsoft Excel (XP Office Suite)

using the following equation after the data had been

converted to UTM format:

d2ab ¼ ðXb� XaÞ2 þ ðYb� YaÞ2

where d is the distance between the points, Xa is the X

coordinate of the first point, Ya is the Y coordinate of the

first point,Xb is theX coordinate of the second point andYb

is the Y coordinate of the second point.

These data were then subsequently statistically analysed

in MINITAB 13 for Windows. The data were tested for

normality using the Anderson–Darling test and found not to

be normally distributed; therefore we opted to analyse the

data using non-parametric statistical tests.

Results

Home-range size

The estimated home-range sizes for the three individuals

varied considerably between individuals and by method of

estimation [minimum convex polygon (MCP) or fixed ker-

nel; Table 1]. Furthermore, the number of fixes (locations)

required before the home ranges of individuals reached an

asymptote also varied greatly (from c. 100 for the adult

female, 375 for the adult male and 1075 for the juvenile

female; see Fig. 1).

Effect of a birth on home-range size and dailyranging

The data showed that the adult female gave birth to an

unknown number of pups on 17 June 2003. To investigate

the effects of a birth on home range, the home ranges of the

three individuals were calculated every 5 days from 40 days

before the birth and for 110 days after the birth (Fig. 2). A

5-day period was chosen as this is a significant period of time

in relation to the gestation period of maned wolves (66 days;

Dietz, 1984), and the large quantity of data we collected

allowed such analyses to be undertaken. We can see that the

home-range sizes of the adult male and juvenile female

remained fairly constant during the observation period,

whereas the female’s home range reduced dramatically after

Table 1 Number of fixes (location) and home ranges (km2) of three

maned wolves Chrysocyon brachyurus calculated using minimum

convex polygon (MCP) and fixed kernel estimators

Individual Fixes MCP 100 MCP 99 MCP 95 Kernel 95

Female 1668 69.10 55.62 48.70 40.17

Male 1676 50.10 40.95 28.97 36.10

Juvenile 1553 39.40 33.78 20.93 7.19

Journal of Zoology 271 (2007) 27–36 c� 2006 The Authors. Journal compilation c� 2006 The Zoological Society of London 29

The secret lives of maned wolvesL. F. Bandeira de Melo et al.

the birth of the pups and thereafter started to increase with

time. Daily ranging did not vary greatly between individuals

or months, even during the period of the birth (Fig. 3),

except during the month of June when the adult female

dramatically reduced her ranging when she gave birth. Daily

ranging returned to pre-birth levels only 5 days after the

birth, whereas home-range size returned to normal only

15–20 days after the birth (see Fig. 2).

Home-range overlap

The data showed that there was considerable overlap

(median=97%; minimum=80% and maximum=100%)

in the use of home ranges by the three individuals. A

Kruskal–Wallis non-parametric analysis of variance showed

that there was no significant difference in the amount of

monthly home-range overlap between the three possible

combinations of individuals (H=1.13; d.f.=2; P=0.568).

There were no significant correlations between home-range

overlap and time (5-day measurements or months), and no

discernible pattern of home-range overlap in relation to time

was observed.

Spatial relationships between individuals

A Friedman test showed that there were no significant

differences between monthly inter-individual distances

(Fr=1.33; d.f.=2; P=0.5134). However, there were sig-

nificant differences between months (Fr=12.33; d.f.=5;

P=0.0305; see Fig. 4), and the post hoc Tukey-type tests

0

10

20

30

40

50

60

70

25 100

175

240

310

385

460

535

615

690

770

845

92010

0010

7511

4512

2012

9013

6514

3515

0515

7516

25

Cumulative number of fixes

Female Male Juvenile

Hom

e ra

nge

(km

)

Figure 1 Cumulative curves of home-range

areas (MCP 100) plotted against cumulative

number of fixes (locations) for the three

maned wolves Chrysocyon brachyurus. MCP,

minimum convex polygon.

05

101520253035404550

−40 −35

−30

−25

−20

−15

−10 −5 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 10

010

511

0

Days in relation to birth

Hom

e ra

nge

(km

)MaleFemale Juvenile

Figure 2 Relationship between home-range

sizes (MCP 100) and birth for three maned

wolves Chrysocyon brachyurus. MCP, mini-

mum convex polygon.

0

2000

4000

6000

8000

10 000

12 000

14 000

−21

−19

−17

−15

−13

−11 −9 −7 −5 −3 −1 1 3 5 7 9 11 13 15 17 19 21

Days in relation to birth event

Tot

al d

ista

nce

trav

elle

din

24

h (m

)

Female Macho Juvenile

Figure 3 Distances travelled in 24-h periods

by the three maned wolves Chrysocyon

brachyurus in relation to the birth of pups.

Journal of Zoology 271 (2007) 27–36 c� 2006 The Authors. Journal compilation c� 2006 The Zoological Society of London30

The secret lives of maned wolves L. F. Bandeira de Melo et al.

showed that the difference was only between the months of

August and October.

Figure 5 shows the spatial relationship of individuals

in relation to the birth of pups. It was observed that the

mean distances between the male and the female

reduced significantly after the birth (comparing the

6weeks before and after the birth; Mann–Whitney

U-test: W=52.0; n1=n2=6; Po0.05) from a mean

distance of 2354� 247 to 1706� 139m. In the same

12-week period the mean distances between the female

and the juvenile also reduced significantly (2422.7� 87.1m

vs. 1810.1� 81.4m; W=56.0; n1=n2=6; Po0.01).

However, the mean distances between the male and

the juvenile were unchanged (W=34.0; n1=n2=6;

P40.05).

Figures 6–8 show the effect of time of day on the spatial

relationships between the three individuals. Overall the data

show that the male and the female stayed in close proximity

0

10

20

30

40

50

60

May June July August September OctoberMonth

Per

cent

age

of fi

xes

with

in d

ista

nce

cate

gory

0–50 m 51–100 m 101–200 m 201–300 m 301–400 m 401–500 m >500 m

Figure 4 Distances between adult male and

adult maned wolves Chrysocyon brachyurus

during the months of observations.

1000

1500

2000

2500

3000

3500

−6 −5 −4 −3 −2 −1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16Weeks in relation to birth event

Mea

n di

stan

ce b

etw

een

indi

vidu

als

(m)

Female-Male Female-Juvenile Male-Juvenile

Figure 5 Mean distances between maned

wolves Chrysocyon brachyurus in relation to

birth of the pups.

0

10

20

30

40

50

60

70

80

90

100

1 3 5 7 9 11 13 15 17 19 21 23Time of day

Per

cent

age

of fi

xes

with

indi

stan

ce c

ateg

ory

0–50 m 51–100 m 101–200 m 201–300 m 301–400 m 401–500 m >500 m

Figure 6 Distances between the adult female

and male in relation to time of day.

Journal of Zoology 271 (2007) 27–36 c� 2006 The Authors. Journal compilation c� 2006 The Zoological Society of London 31

The secret lives of maned wolvesL. F. Bandeira de Melo et al.

to each other during daylight hours, whereas all individuals

avoided each other at night.

Daily range

The female maned wolf moved the greatest distances

between sampling points per month, except for the month

of June when she gave birth (see Fig. 3). However, a

Kruskal–Wallis non-parametric analysis of variance showed

that these differences between individuals were not statisti-

cally significant (H=2.95; d.f.=2; P=0.229). The data for

the whole study period showed that during an average day

(12 sample points), the female moved a mean total of

9039� 238m (mean� SEM; minimum=112 and max-

imum=15 807), the male 7012� 192m (mean� SEM; mini-

mum=857 and maximum=15 388) and the juvenile

6165� 161m (mean� SEM; minimum=2588 and max-

imum=12 062). A Friedman repeated-measures analysis of

0102030405060708090

100

Time of day

Per

cent

age

of fi

xes

indi

stan

ce c

ateg

ory

0–50 m 51–100 m 101–200 m 201–300 m 301–400 m 401–500 m >500 m

1 3 5 7 9 11 13 15 17 19 21 23Figure 7 Distances between the adult male

and the juvenile female in relation to time

of day.

0102030405060708090

100

Time of day

Per

cent

age

of fi

xes

indi

stan

ce c

ateg

ory

0–50 m 51–100 m 101–200 m 201–300 m 301–400 m 401–500 m >500 m

1 3 5 7 9 11 13 15 17 19 21 23Figure 8 Distances between the adult female

and the juvenile female in relation to time

of day.

0

200

400

600

800

1000

1200

1400

1600

1 3 5 7 9 11 13 15 17 19 21 23Time of day (h)

Med

ian

dist

ance

mov

ed (

m)

Female Male Juvenile

Figure 9 Median distance moved (m) between

sample points in relation to time of day.

Journal of Zoology 271 (2007) 27–36 c� 2006 The Authors. Journal compilation c� 2006 The Zoological Society of London32

The secret lives of maned wolves L. F. Bandeira de Melo et al.

variance showed that these daily median totals were signifi-

cantly different (Fr=75.38; d.f.=2; Po0.001), and a post

hoc Tukey-type test showed that the female’s median daily

total was significantly greater than that of both the male and

the juvenile (there was no statistically significant difference

between the juvenile and the male). A Spearman rank

correlation of the daily median total distance travelled

against month showed significant positive correlations for

the female (rs=0.943; n=6; Po0.01) and the juvenile

(rs=1.000; n=6; Po0.001) but not for the male

(rs=0.558; n=6; P=0.228).

Activity during 24 h

Figure 9 shows that the three individuals displayed predo-

minantly nocturnal activity throughout the study period

from May to October. During this period sunrise would

have occurred between 06:00 and 07:00 h, and sunset

between 17:30 and 18:30 h. In the case of the female she

showed two peaks of activity: one at sunrise and the other

1–2 h after sunset. The juvenile female also showed a peak of

activity at sunrise but not after sunset, whereas the male

showed a small peak of activity 1–2 h before sunrise but

again no peak after sunset.

Discussion

The results of this paper strongly challenge the currently

held theory that maned wolves live largely solitary lives

(Dietz, 1984). Here we show for the first time that an adult

pair associates spatially with each other before, during and

after a birth of pups (Figs 6–8). This spatial association has a

diurnal nature, with the pair spending an average of 82% of

their time during daylight hours within 50m of each other.

However, during the night, when they are hunting, the adult

pair seemed to be actively avoiding each other (see Figs 6–8).

Therefore, our data strongly suggest that maned wolves may

indeed be social animals, but we do not have direct beha-

vioural observations to confirm what type of social beha-

viour they are expressing. Certainly, the spatial relationships

between individuals and the female were stronger (as mea-

sured by the distance between individuals; Fig. 5) when the

female had pups, which strongly suggests parental care

behaviour being expressed by the male and potentially the

juvenile female as a helper. The male also showed a

protracted and strong spatial association with the female

before her pups were born. This may reflect mate guarding

by the male, as occurs in the red fox Vulpes vulpes, which

was once thought to be monogamous (Harris & White,

1994; Baker et al., 2004).

Home-range size

The home-range sizes reported in this study are within the

limits of home ranges reported by other authors for maned

wolves, which vary between 21.7 and 115 km2 (Dietz, 1984,

1985; Carvalho and Vasconcellos, 1995). For many species,

home-range size is obviously a function of environmental

quality; that is, in general we find a negative correlation

between home-range size and the level of food resources

within any given environment (Herfindal et al., 2005). One

interesting methodological issue we had in relation to

calculating home-range size was whether MCP 100 or MCP

95 was most appropriate because of our large sample sizes

per animal (more than 1500 fixes). Using MCP 95, we were

discarding between 75 and 80 fixes per animal, which is the

number of fixes frequently used to calculate home ranges in

conventional radio-telemetry studies (e.g. Dietz, 1984).

Therefore, we also calculated MCP 99, whereby only 15–16

of the most outlying points were not included in our

analyses.

Given the large quantity of data we had available, we also

calculated home ranges in 5-day blocks, which gave means

of between 7.5 and 28.5 km2 (Fig. 2). Obviously, here we are

using a limited number of data points (60), but this magni-

tude of sample size has been used by other researchers to

calculate home ranges (Dietz, 1984). These data, when

compared with the final estimates of home range (Table 1),

show the importance of collecting many fixes and over a

prolonged period of time, thereby allowing home-range data

to reach an asymptote. It is important to collect home-range

data over long periods of time, because this will avoid

problems of autocorrelations between fixes (Harris et al.,

1990).

A further interesting point arose in relation to the number

of fixes before reaching asymptotic home-range size. We

saw in Fig. 1 that the female’s home-range size became

asymptotic quickly (around 100 fixes). However, this

asymptote may be an artefact because the female appeared

to be searching for a nest site before giving birth and was

therefore increasing her home range. It is interesting to note

that both the male and the juvenile needed hundreds of fixes

before their home ranges stabilized. In the case of the

juvenile, this may reflect the increasing physiological

needs of a growing animal or her need to explore and

gather information about her environment. In the case of

the male, the lack of reaching an asymptotic home

range may be related to the breeding season or may simply

reflect the dynamic nature of environmental use by

adult maned wolves. These data certainly suggest that

other researchers should be extremely cautious when

calculating and interpreting home-range sizes when less

than several hundred location fixes are available, especially

if fixes were collected in a short period of time (Harris et al.,

1990).

Home range and birth

For the 40 days before the birth of her pups, the female in

our study was seen to be increasing and decreasing her home

range (Fig. 2). There are three possible explanations for this

pattern of home range: (1) the female was procuring more

food due to increasing energetic demands because of her

pregnancy, (2) the female was procuring a birth site (nest/

den) and her increase in home range reflects search effort,

and (3) the female was responding to decreased prey avail-

ability by increasing her home range. The data best fit

Journal of Zoology 271 (2007) 27–36 c� 2006 The Authors. Journal compilation c� 2006 The Zoological Society of London 33

The secret lives of maned wolvesL. F. Bandeira de Melo et al.

hypothesis (2), the female searching for an appropriate

birthing site, because if she was simply responding to

increasing energetic demands she could simply increase her

activity levels within her existing home range, assuming prey

density was not limiting. However, in Fig. 3 we can see that

the distanced travelled within a 24-h period did not increase

before the female gave birth.

Immediately following the birth of her pups, the female

dramatically reduced her home-range size and distance

travelled within a 24-h period. This was obviously in

response to her need to dedicate time for parental care of

her pups. Simultaneously, the male also reduced his home-

range size and activity levels, suggesting that the male was

also providing parental care. This reduction in home-range

size was not observed in the juvenile (see Fig. 2). These data

support observations of captive studies, which suggest that

the male plays an important role in the care of offspring

(Dietz, 1984; Rasmussen & Tilson, 1984; Veado, 1997).

Furthermore, before the birth of the pups on 17 June

2003, the juvenile female spent only 2 h at exactly the

same location as that of the female in 40 days, whereas

after the birth of the pups she spent 48 h at the same

location in the following 70 days. Interestingly, on the day

after the birth she spent 6 continuous hours with the female

and presumably, therefore, the pups. The exact function of

the juvenile female’s visit remains unknown, but we can

propose various hypotheses to be tested: from helping

behaviour to simple curiosity. Undoubtedly, the birth of

pups created the emission of new stimuli, such as scents in

the environment, which may have attracted the juvenile

female. The male at this point remained close to the birth

site, but our GPS collars did not detect him at the same

point as the birth site (but we need to point out that our

sampling was not continuous). During the weeks and

months after the birth of the three pups (as confirmed by

direct observations and camera traps), the juvenile female

visited her mother and presumably the pups on several

occasions (five times in the first month, four times in the

second month, etc.). The purpose of such visits remains

unclear, and in future studies we hope to place video

cameras at the nest site to confirm whether ‘helping’ occurs

in maned wolves.

The area chosen for the birth site was an open area of

cerrado covered in tall grass species (at least 1m high) with a

small tree beside the birth site. Visual inspection of the birth

site, after the female had left it with her pups, showed that it

comprised a maze of grass tunnels. In this study we encoun-

tered many sleeping sites for maned wolves, and their

structure was different from the birth site in that they did

not contain any tunnels within the local vegetation. We

suspect that the female used these tunnels to move the pups

around, probably as an anti-predator strategy. Our camera

traps photographed several potential predators of maned

wolf pups, such as pumas Puma concolor and feral dogs

Canis familiaris. A similar pattern of cub movement has

been observed in female cheetahs, which may be in response

to predators and the build-up of parasites in the den

(Laurenson, 1993).

Home-range overlap

The female had the largest home range of the individuals in

our study (see Table 1), and the data show that the male and

the juvenile lived within the female’s home range. However,

both the male and the juvenile did have very small areas

where the female did not visit. Therefore, we conclude that

the degree of tolerance between related individuals in the

wild may be high when environmental conditions permit

(i.e. good food abundance). Why the female has a home

range much larger than the male is not clear. This could

reflect a greater energetic demand or the simple fact that she

needs to procure certain sex-specific resources, such as a

nesting site. Another interesting observation is that our

camera traps photographed other males in the area sur-

rounding our study subjects’ home ranges. It could be that

the presence of other males nearby limited the home-range

size of the male in our study, as has been observed in white

rhinoceros Ceratotherium simum (Rachlow, Kie & Berger,

1999).

The fact that one (we only observed one juvenile female

within the female’s home range) and possibly more juveniles

stay within the home range of their mother is interesting,

and this has also been observed in other reserves (e.g. RPPN

Serra do Caraca; R. J. Young, pers. obs.). This suggests an

extended learning period in maned wolves, which is most

probably related to learning the spatial distribution of

resources, and not hunting skills, as in other carnivore

species, such as cheetahs Acinonyx jubatus (Caro, 1994).

We feel confident in saying this because maned wolves are

spatially separated at night when hunting (see Figs 6–8) and,

therefore, a hunting juvenile cannot learn from an adult.

Furthermore, in comparison with other carnivores the

maned wolf has a much larger area of its brain dedicated

to spatial memory (Dunbar & Bever, 1998), suggesting a

necessity to learn about its environment.

Spatial relationships between individuals

Figure 6 clearly shows that the adult pair normally sleep

together or in close proximity during daylight hours, and

then when active at night they strongly avoid one another.

Figures 7 and 8 show a similar pattern, with the juvenile

attempting to sleep close to her parents during the day and

apparently actively avoiding them at night. These data

suggest that social bonds between adult pairs may be

stronger than previously thought (see Dietz, 1984), espe-

cially because this pattern of association was seen before the

birth of the pups (Fig. 5). It could be argued that the maned

wolves slept together because of the scarce availability of

suitable sleeping sites. However, then we would expect all

pairwise comparisons between individuals to show the same

result, which they clearly did not. These data strongly

suggest that social behaviour is important to maned wolves,

and this is a topic that should be addressed in the field

through direct behavioural observations. The relationship

between the juvenile and her parents is intriguing and may

suggest that the juvenile had an important role in the

Journal of Zoology 271 (2007) 27–36 c� 2006 The Authors. Journal compilation c� 2006 The Zoological Society of London34

The secret lives of maned wolves L. F. Bandeira de Melo et al.

reproductive success of her parents, perhaps acting as a

helper.

The apparent active avoidance of other individuals at

night seems most probably a strategy that wild maned

wolves adopt to avoid one animal interfering with the

hunting behaviour of another individual. For example, after

a predator has recently moved through a specific area, many

prey species may have already sought cover, and therefore

would be more difficult to capture. The hunting method of

maned wolves may also encourage mutual avoidance; the

use of their large ears to pinpoint the sounds of rodent prey

in tall grass would soon be compromised by the presence of

others. In otters Lontra canadensis, individuals avoid hunt-

ing close together to increase individual capture rates and to

reduce intra-specific competition (Melquist & Hornocker,

1983).

For the 6weeks after the birth of the pups, both the male

and the juvenile reduced their mean distances to the female,

and increased their frequency of encounters with the female.

These data suggest that both individuals may have been

involved in the care of the pups. Studies in captivity have

demonstrated that the male will often bring food to a female

who has pups (Dietz, 1984; Rasmussen & Tilson, 1984;

Veado, 1997).

Daily range

The daily ranges of maned wolves varied considerably,

ranging from 0.07 to 16 km, and obviously the birth of pups

greatly affected the ranging of the female. On average, adult

and juvenile maned wolves ranged between 6 and

9 kmday�1. The ranging of both the female and the juvenile

generally increased during our study, especially towards the

end of the study. It should be noted that our study

terminated as the rainy season began in 2003. During the

rainy season, prey availability is reported to be significantly

lower than in the dry season (Alho et al., 1986), which

implies that animals need to expend greater hunting effort in

the wet season. This may explain why animals increased

their home ranges at the end of this study (see Fig. 2).

Activity during 24 h

From the data in this study, we show that, as found in other

studies (Dietz, 1984), maned wolves are strongly nocturnal

with peaks of activity at dawn and dusk (i.e. crepuscular).

The crepuscular activity peaks seemed to be more pro-

nounced in the adult female in comparison with the other

two individuals. However, in other areas of Brazil maned

wolves can be active during daylight hours (e.g. in Serra da

Canastra National Park, Minas Gerais).

Conclusions

The conclusions presented here are based on data pertaining

to three individuals. Therefore, some caution must be used

so as not to overgeneralize, because individual variation in

the variables described in this study could occur (see Lott,

1984). The results presented in this article have implications

for both in situ and ex situ conservation of this species. The

data presented here suggest strongly that maned wolves are

more social than previously thought and may, like other

canid species, have rich and complex social lives. However,

to reveal more details about the lives of wild maned wolves,

direct behavioural field observations are required.

Acknowledgements

We thank CEMIG (Companhia Energetica de Minas Ger-

ais) for their financial and logistical support, without which

this project would not have been possible. We are grateful to

the group of CEMIG from RPPN Galheiro Environmental

Station for their support. This article was greatly improved

by the comments of Dr Andrew Kitchener, Dr Ron Swais-

good and Prof. Sonia Talamoni. Televilt’s staff was most

helpful in answering our queries about the use of GPS

collars. This study was conducted in compliance with the

appropriate Brazilian laws in enforcement at the time of the

study, and we wish to thank IBAMA for their permission to

carry out this study.

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