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acta ethologica
ISSN 0873-9749
acta ethol
DOI 10.1007/s10211-016-0241-4
Infanticide in a jaguar (Panthera onca)
population—does the provision of livestock
carcasses increase the risk?
Fernando R.Tortato, Allison L.Devlin,
Rafael Hoogesteijn, Joares A.May
Júnior, Jacqueline L.Frair, Peter
G.Crawshaw, et al.
1 23
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SHORT COMMUNICATION
Infanticide in a jaguar (Panthera onca)population—does
the provision of livestock carcasses increase the risk?
Fernando R. Tortato
1
&Allison L. Devlin
2,3
&Rafael Hoogesteijn
1
&
Joares A. May Júnior
1,4
&Jacqueline L. Frair
2
&Peter G. Crawshaw Jr.
5
&
Thiago J. Izzo
6
&Howard B. Quigley
3
Received: 31 May 2016 / Revised: 8 September 2016 /Accepted: 3 October 2016
#Springer-Verlag Berlin Heidelberg and ISPA 2016
Abstract Infanticide is an antagonistic behavior that may
provide an evolutionary benefit for the perpetrator. Cases of
infanticide have rarely been reported in Neotropical carni-
vores. The objective of this study was to provide empirical
evidence of infanticide in a local jaguar (Panthera onca)
population in the Brazilian Pantanal. We present infanticide
data from opportunistic sampling. Each month, from 2013
to 2015, we monitored pastures for evidence of livestock
carcasses. A remotely triggered camera trap was placed at
encountered fresh cattle carcasses. Through this monitoring,
two cases of infanticide were recorded. Both cases occurred
in close proximity to a cattle carcass, a large prey item that
may attract multiple jaguars—including females with cubs
around age of weaning—and increase the risk of infanti-
cide. Our observations provide new empirical evidence of
jaguar social behavior and intraspecific competitive
interactions, potentially driven by locally high population
density and resource provision.
Keywords Camera trap .Infanticide .Livestock .Pantanal .
Panthera onca
Infanticide occurs when an infant or juvenile is killed by an
older conspecific (Ebensperger 1998; Balme and Hunter
2013). Infanticide may stem from neutral or pathological be-
havior or may provide a selective advantage to the perpetrator
through increased access to mates or resources (Hrdy 1979;
Sussman et al. 1995; Rees 1999). In the context of sexual
selection, an unrelated male perpetrator may gain reproductive
advantages with a desired female mate by dispatching depen-
dent offspring (Hrdy 1979; Trivers 1985). For example, adult
male bears (Ursus arctos) may commit infanticide to bring
females into estrus, thus increasing reproductive fitness of
themale(Bellemainetal.2006). In other cases, the perpetrator
may benefit from direct use of the victim through predation
and consumption of the victim (Hrdy 1979; Ebensperger
1998;Digby2000; Balme and Hunter 2013). Additional pos-
sible drivers include environmental stress, social rank (where
high-ranking individuals assert dominance over lower-
ranking individuals within a group), nutritional deficiency,
high population density, or low infant viability (Braastad and
Bakken 1993; Schmalz-Peixoto 2003; Casar et al. 2008).
Information about infanticide in carnivores is difficult to
obtain in the wild, as many species are secretive, solitary, have
nocturnal activity patterns, and females actively hide their
young in secluded places (Packer and Pusey 1984;
Bellemain et al. 2006; Balme and Hunter 2013). Infanticide
is most frequently documented in African lions (Panthera
leo), where new males joining a pride may kill unrelated off-
spring (Bertram 1975; Packer and Pusey 1983). Additional
*Fernando R. Tortato
ftortato@panthera.org
1
Panthera, Pantanal Jaguar Project, Box 3203, 78060970, Cuiabá,
Mato Grosso, PO, Brazil
2
Department of Environmental & Forest Biology, SUNY College of
Environmental Science & Forestry, 1 Forestry Drive,
Syracuse, NY 13210, USA
3
Panthera, 8 West 40th Street, 18th Floor, New York, NY 10018, USA
4
UNISUL, Avenida José Acácio Moreira 787, PO Box 370,
Tubarão, Santa Catarina 78704900, Brazil
5
Centro Nacional de Pesquisa para a Conservação de Mamíferos
Carnívoros –CENAP/ICMBIO, Rua do Salmão, 330, PO Box 45,
Passo de Torres, Santa Catarina 88980-000, Brazil
6
Departamento de Ecologia e Botânica, Universidade Federal de Mato
Grosso, Avenida Fernando Correa da Costa N° 2.367. Bairro Boa
Esperança, 78060-900, Cuiabá, Mato Grosso, Brazil
acta ethol
DOI 10.1007/s10211-016-0241-4
Author's personal copy
reports of infanticide events have been reported in other felid
species including cougars (Puma concolor; Logar and
Sweanor 2001), lynx (Lynx spp.; Quinn and Parker 1987),
and ocelot (Leopardus pardalis; Emmons 1988). Female ti-
gers with cubs may attempt to reduce the risk of infanticide by
modifying their territory or through direct defensive interac-
tions with aggressive (likely unrelated) males (Singh et al.
2014). Goodrich et al. (2008) evaluated the causes of mortality
in Amur tigers and reported six cases of probable infanticide.
A study on leopards documented 14 confirmed and 15 prob-
able cases of infanticide, with all cases perpetrated by males
(Balme and Hunter 2013).
In jaguars (Panthera onca), little is known about the causes
of mortality at any given age. Human-induced mortality, in-
cluding hunting and preventive control for livestock depreda-
tion, is an important source throughout much of the jaguar’s
range (Hoogesteijn and Mondolfi 1992; Crawshaw 2002).
Deaths from natural causes are rarely documented. One case
of cannibalism was observed in the southern Brazilian
Pantanal, where an adult female jaguar was reportedly killed
and consumed by two adult males (Azevedo et al. 2010).
Jaguar cub remains have been found in the stomach contents
of hunted adult males in Venezuela (Hoogesteijn and
Mondolfi 1992). There has been only one prior case of infan-
ticide documented for jaguars in the Central region of Brazil
where two male cubs were killed by their father; paternity was
later confirmed through DNA analyses (Soares et al. 2006).
Here we present two probable cases of infanticide of a 3-
month-old and a 4-month-old jaguar cub. The first case is
based on the detection of a dead cub, opportunistically found
during routine field surveys. The second case is based on
photographic evidence from a cattle carcass monitored by a
camera trap. We discuss our findings in the context of the
sociality of this solitary species.
The study was conducted in the northern Pantanal of
Brazil, an inland wetland covering an area of 140,000 km
2
.
Over 95 % of this wetland is comprised of private cattle
ranches (Harris et al. 2005). The main economic activity in
the Pantanal is cattle ranching, a practice which began over
250 years ago (Wilcox 1992). Cattle are kept in a mosaic of
vast natural grassland and forested areas, including riparian
forests and natural forest patches. The Pantanal has distinct
dry (April–September) and wet (October–March) seasons.
Our observations took place during the dry season at São
Bento (17° 20′S, 56° 42′W), a privately owned cattle ranch.
The study area covers 270 km
2
dedicated to ranching with a
herd of approximately 4000 cattle (Bos indicus). The area is
characterized by a mosaic of forest, native grassland, and pas-
ture along two major rivers (Cuiabá and Piquiri) and standing
bodies of water of different sizes, both permanent and season-
al. All activities were authorized by the Conselho Nacional de
Desenvolvimento Científico e Tecnológico - CNPq
(Publicação Portaria MCTI n° 145/12, Processo Expedição
Científica n° 000179/2010-8) and SISBIO (n° 21447-2 e n°
21447-3). Handling of specimens was approved by SUNY
ESF Institute of Animal Care and Use Committee (#110202,
Syracuse, NY, USA).
Jaguars are unique among carnivores in that they kill prey
with a single bite through the skull (Schaller and Vasconcelos
1978). This trademark provides definitive evidence of species-
specific predation events (Hoogesteijn and Mondolfi 1992).
Each month, from 2013 to 2015, we monitored pastures for
evidence of livestock carcasses. Any carcass found with the
characteristic canine puncture in the skull was determined as a
jaguar kill. A remotely triggered camera trap (Pantheracam
v.3.0, New York, NY, USA) was placed at all 22 encountered
fresh (<24 h old) cattle carcasses and left in place for a min-
imum of 1 day and maximum of 4 days. From the photo-
graphs, we recorded visitation and identity of individual jag-
uars by their unique rosette patterns, as well as age and repro-
ductive state. Age was determined using overall body size and
proportions, and, when visible, dentition to classify individ-
uals as cubs, dispersal-aged subadults (16–25 months old), or
adults. Reproductive state was evidenced by the presence or
absence of distended mammary glands. Jaguars typically have
between 1 and 4 cubs per litter; in captivity, cubs were con-
sidered pre-weaning (nursing) at ≤5monthsofageandpost-
weaning at >5 months of age (Stehlik 1971; Sunquist and
Sunquist 2002). Cub carcasses were examined by the team,
either through direct handling or examination of photographic
evidence. For the physically recovered carcass, a necropsy
was performed to determine cause of death and estimate indi-
vidual age and body condition. Cub age was estimated based
on tooth condition and overall body size (e.g., Stander 1997).
All jaguar visitations to the carcasses occurred within 48 h
of initial monitoring. In nine events, single individuals visited
the carcass and in the other 13 cases we observed resource
partitioning and visitation by multiple individuals. Females
with cubs visited six of the 22 carcasses (27.3 %). In three
cases, up to three adult individuals visited a livestock carcass
in a single night.
The carcass of one cub (C01; Fig. 1a) was found on 26
June 2013 close to a live-trap installed to capture jaguars for
a telemetry study. The body of the cub had not yet entered
rigor mortis, so time of death was likely within 8 h of discov-
ery. The cub was found under a wire fence line. A search of the
area produced evidence of drag marks in the dry soil and
directional displacement of vegetation, indicating the cub
was dragged over a distance of 100 m until finally deposited
at the location of discovery. Results from the necropsy indi-
cated that the cause of death was due to a single puncture to
the skull characteristic of the canine bite pattern of an adult
jaguar (Fig. 1b). Based on its small body weight (10 kg), small
total body length (108 cm), and dentition, we estimated the
cub was about 3 months old. Recovered stomach contents
included about 400 g of cow hair and bone fragments, which
acta ethol
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indicated the cub had recently fed at a cattle carcass. The
nearest known cattle carcass at that time was 200 m from the
recovery site. The perpetrator was not individually identified.
The cub skin was catalogued in the mammal collection at the
Federal University of Mato Grosso state (UFMT, catalog
number UFMT-4014).
Photographic evidence of a second infanticide event was
recorded at a cattle carcass monitored from 27 to 28 August
2013. Three individual jaguars visited the carcass during this
monitoring window: one lactating adult female (F01), one
non-lactating adult female (F02), and one 4-month-old cub
(C02). Based on these characteristics, we concluded that
C02 was the cub of F01. The photo sequence on 27 August
records F01 (17:12 h) at the carcass first, followed about an
hour later by F02 (18:34 h) and 8 min later by C02 (18:42 h).
The final photograph (19:39 h) in this sequence shows F02
with C02, presumably dead, in her mouth (Fig. 2a). Although
F02 was not lactating, the image is similar to a mother carry-
ing her cub (Fig. 2b); however, we concluded that the cub was
likely dead at time of photograph as its tongue was hanging
out of its mouth, hind end dragging on the ground, and jaw of
F02 was closed at an acute angle. Despite extensive searches
of the area, the cub was not recovered so we could neither
confirm mortality nor accurately determine age. Based on
body size, the cub appeared to be about 4 months old. Both
F01 and F02 were photographed at different times at the car-
cass during the morning of 28 August, after which time no
additional visits were recorded.
With only one other published incidence of infanticide by
jaguar (Hoogesteijn and Mondolfi 1992), our records provide
important empirical evidence on a rarely observed aspect of
jaguar sociality. Despite the small sample size and opportunis-
tic nature of our sampling, the two case studies presented here
can be examined in the broader context of felid behavior. We
were able to identify the sex of one of the possible perpetra-
tors, an adult female, which is unusual for large cats given that
adult males are the typical culprits in other species (Bertram
1975; Packer and Pusey 1983,1984;Soaresetal.2006;
Fig. 1 a Photograph of the carcass of C01, recovered 26 June 2013. The
carcass was dragged about 100 m from apparent site of predation at the
edge of a small thicket and was left underneath a fence line. bResults
from the necropsy indicated a fatal bite to the skull with multiple
fractures. This injury was consistent with the typical kill method of
jaguars
Fig. 2 a Infanticide of cub C02 by resident female jaguar F02. The
camera trap was placed at the cattle carcass, where assumed mother F01
was first photographed. Subsequent records indicate an encounter
between C02 and F02, resulting in the above photograph. Note the
tongue hanging outside the mouth of C02, and the acute angle of the
jaws of F02. bImage of a jaguar mother carrying her cub in the San
Diego Zoo (photo by Debbie Beals). In this natural behavior, the cub is
not relaxed and does not touch the ground. Note that the tongue is not
outside of the mouth, unlike observed in Fig. 2a
acta ethol
Author's personal copy
Balme and Hunter 2013). Infanticide by female wild felids has
been rarely documented, although Schaller (1972) reported
cases of female lions killing offspring from competing
prides and Rudnai (1973) presented cases of maternal infanti-
cide in lions in Eastern Africa. The two likely cases of infan-
ticide in jaguars in the Pantanal had one characteristic in com-
mon: the victims were at or near a cattle carcass, a prey item
providing roughly twice the biomass of the majority of wild
prey items for jaguars (e.g., tapirs Tapirus terrestris < 300 kg;
capybara Hydrochoerus hydrochaeris < 90 kg; white-lipped
peccary Tayassu pecari < 40 kg). Large domestic prey such as
cattle, buffalo (Bubalus bubalis), and horses (Equus caballus)
may attract locally high concentrations of individual jaguars,
increasing the likelihood of antagonistic interactions among
jaguars and—by extension—the risk of infanticide.
A single jaguar may remain at a large livestock carcass for
up to 4 days (Cavalcanti and Gese 2010). This long handling
time increases the likelihood of interactions between different
individuals, either in sharing or aggressively competing for
access to the carcass. Risk of infanticide may be increased
when females bring cubs to feed at the carcass and are unable
to defend the cubs against other mature jaguars. Small cubs
(≤5 months old) may be more vulnerable to infanticide by
aggressive interactions with larger jaguars. This may also have
direct consequences for conflict between jaguars and cattle
ranchers. The increased predator activity around cattle car-
casses may cause more direct human-predator conflict, intro-
ducing additional pressure on cub and adult jaguar survival.
There is a highdensity of jaguar at the São Bento study site,
with approximately 8.0 individuals per 100 km
2
(A. Devlin,
unpublished data), compared to densities of 6.5–7.0 individ-
uals per 100 km
2
as reported in other regions within the
Pantanal (Soisalo and Cavalcanti 2006; Azevedo and
Murray 2007; Cavalcanti et al. 2012). This density is higher
than in other biomes where the jaguar occurs, including the
Atlantic Forest (1.7 individuals / 100 km
2
, Paviolo et al.
2008), Amazon (4.4 individuals / 100 km
2
, Tobler et al.
2013), and Brazilian Cerrado grassland (0.6 individuals
/100 km
2
, Sollmann et al. 2011). This locally high density
may contribute to an increased frequency of intraspecific or
density-dependent interactions. Population density and social
stress have been related to increased aggression in several
species of mammals (Logan and Sweanor 2001). To reduce
the risk of infanticide, female brown bears (Ursus arctos)with
cubs avoid areas where resources are spatially aggregated,
such as salmon streams where there is a concentration of adult
bears consuming the same resource (Ben-David et al. 2004).
Female jaguars with cubs were not recorded around smaller
prey items such as green turtle (Chelonia mydas) carcasses
(Guilder et al. 2015), but conspecific interactions have been
previously recorded around other wild prey carcasses
(Cavalcanti and Gese 2009,2010). In the Pantanal, the aver-
age interval between livestock depredation by jaguars ranges
from 11 (Tortato et al. 2015) to 13 days (Cavalcanti and Gese
2010). This frequency in livestock consumption is similar to
the consumption of wild prey in this region (Cavalcanti and
Gese, 2010). Thus, cattle carcasses may be a useful predictor
for jaguar distribution and intraspecific competition.
In both case studies presented here, the infanticide events
provide evidence of young cubs consuming cattle. Females
with cubs near age of weaning (around 3–5monthsold)
may bring their young directly to an available food source as
cub nutritional needs develop during the transition from nurs-
ing to consumption of solid food. This crucial developmental
step may potentially increase the risk of infanticide in areas of
high density with conspecifics.
Acknowledgments The authors thank fellow colleagues at ICMBio-
CENAP (Atibaia, SP, Brazil) and Instituto Pro-Carnívoros for their sup-
port and collaboration throughout the years of research. We extend our
gratitude for the assistance from the Pantaneiros of São Bento ranch.
Funding for this project was provided in part by Panthera’s Kaplan
Graduate Award (A.L. Devlin). Scholarships were granted to F.R.
Tortato by Fundação de Amparo à Pesquisa do Estado de Mato Grosso
- FAPEMAT. The majority of field support was funded by Panthera’s
Jaguar Research Program.
References
Azevedo FCC, Murray DL (2007) Spatial organization and food habits of
jaguars (Panthera onca) in a floodplain forest. Biol Cons 137:391–
402
Azevedo FCC, Costa RL, Concone HVB, Pires-da Silva A, Verdade LM
(2010) Cannibalism among jaguars (Panthera onca). Southwest Nat
55:597–599
Balme GA, Hunter LTB (2013) Why leopards commit infanticide. Anim
Behav 86:791–799
Bellemain E, Swenson JE, Taberlet P (2006) Mating strategies in relation
to sexually selected infanticide in a non-social carnivore: the brown
bear. Ethology 112:238–246
Ben-David M, Titus K, Beier LR (2004) Consumption of salmon by
Alaskan brown bears: a trade-off between nutritional requirements
and the risk of infanticide? Oecologia 138:465–474
Bertram BCR (1975) Social factors influencing reproduction in wild
lions. J Zool 177:463–482
Braastad BO, Bakken M (1993) Maternal infanticide and periparturient
behavior in farmed silver foxes Vulpes vulpes. Appl Anim Behav Sci
36:347–361
Casar C, Franco ES, Soares GCN, Young RJ (2008) Observed case of
maternal infanticide in a wild group of black-fronted titi monkeys
(Callicebus nigrifrons). Primates 49:143–145
Cavalcanti SMC, Gese EM (2009) Spatial ecology and social interactions
of jaguars (Panthera onca) in the southern Pantanal, Brazil. J
Mammal 90:935–945
Cavalcanti SMC, Gese EM (2010) Kill rates and predation patterns of
jaguars (Panthera onca) in the southern Pantanal, Brazil. J Mammal
91:722–736
Cavalcanti SMC, Azevedo FCC, Tomás WM, Boulhosa RLP, Crawshaw
PG, Jr (2012) The status of the jaguar in the Pantanal. Cat News
Special Issue 7:29–34
Crawshaw PGJr (2002) Mortalidadinducida por humanosy conservación
de jaguares: el Pantanal y el parque nacional Iguaçu en Brasil. In:
acta ethol
Author's personal copy
Medellin RA, Equihua C, Chetkiewicz CLB, Crawshaw Jr PG,
Rabinowitz A, Redford KH, Robinson JG, Sanderson EW, Taber
AB (eds) El jaguar enelnuevo milênio, Fondo de Cultura
Economica. Universidad Nacional Autonoma de Mexico y
Wildlife Conservation Society, Mexico, pp. 451–463
Digby LJ (2000) Infanticide by female mammals: implications for the
evolution of social systems. In: Van Schaik CP, Janson CH (eds)
Infanticide by males and its implications. Cambridge University
Press, Cambridge, pp. 423–446
Ebensperger LA (1998) Strategies and counterstrategies to infanticide in
mammals. Biol Rev 73:321–346
Emmons LH (1988) A field studyof ocelots (Felis pardalis) in Peru.
Revue D’Ecologie (La Terre et laVie) 43:133–157
Goodrich JM, Kerley LL, Smirnov EN, Miquelle DG, MacDonald L,
Quiqley HB, Hornocker MG, McDonald T (2008) Survival rates
and causes of mortality of Amur tigers on and near the Sikhote-
Alin Biosphere Zapovednik. J Zool 276:323–329
Guilder J, Barca B, Arroyo-Arce S, Gramajo R, Salom-Pérez R (2015)
Jaguars (Panthera onca) increase kill utilization rates and share prey
in responseto seasonal fluctuations in nesting green turtle (Chelonia
mydas mydas) abundance in Tortuguero National Park, Costa Rica.
Mamm Biol 80:65–72
Harris MB, Tomás WM, Mourão G, Silva CJ, Guimarães E, Sodona F,
Fachim E (2005) Safeguarding the Pantanal wetlands: threats and
conservation initiatives. Conserv Biol 19:714–720
Hoogesteijn R, Mondolfi E (1992) El jaguar, tigre Americano. Ediciones
Armitano, Caracas
Hrdy SB (1979) Infanticide among animals: a review, classification, an
examination of the implications for the reproductive strategies of
females. Ethol Sociobiol 1:13–40
Logan KA, Sweanor LL (2001) Desert puma–evolutionary ecology and
conservation of an enduring carnivore. Island Press, Washington,
D.C.
Packer C, Pusey AE (1983) Adaptations of female lions to infanticide by
incoming males. Am Nat 121:716–728
Packer C, Pusey AE (1984) Infanticide in carnivores. In: Hausfater G,
Hrdy SB (eds) Infanticide: comparative and evolutionary perspec-
tives. Aldine Publishing Company, New York, pp. 31–42
Paviolo A, De Angelo CD, Di Blanco YE, Di Bitetti MS (2008) Jaguar
Panthera onca population decline in the Upper Parana’Atlantic
Forest of Argentina and Brazil. Oryx 42:554–561
Quinn NWS, Parker G (1987) Lynx. In: Novak M, Baker JA, Obbard
ME, Malloch B (eds) Wild furbearer management and conservation
in North America. Ministry of Natural Resources, Ontario, pp. 682–
695
Rees A (1999) The infanticide controversy: primatology and the art of
field science. Dissertation. University of Chicago Press, Chicago
Rudnai J (1973) Reproductive biology of lions (Panthera leo massaica
Neumann) in Nairobi National Park. Afr J Ecol 11:241–253
Schaller GB (1972) The Serengeti lion: a study of predator-prey relations.
University of Chicago Press, Chicago
Schaller GB, Vasconcelos JMC (1978) Jaguar predation on capybara. Z
Säugetierk 43:296–301
Schmalz-Peixoto KE (2003) Factors Affecting Breeding in Captive
Carnivora. Dissertation. University of Oxford, Oxford
Singh R, Nigam P, Qureshi Q, Goyal S (2014) Strategy of female tigers to
avoid infanticide. Curr Sci 107:1595–1597
Soares TN, Telles MPC, Resende LV, Silveira L, Jácomo ATA, Morato
RG, Diniz-Filho JAF, Eizirik E, Brondani RPV, Brondani C (2006)
Paternity testing and behavioral ecology: a case study of jaguars
(Panthera onca) in Emas National Park, Central Brazil. Genet Mol
Biol 29:735–740
Soisalo MK, Cavalcanti SMC (2006) Estimating the density of a jaguar
population in the Brazilian Pantanal using camera-traps and capture-
recapture sampling in combination with GPS radio-telemetry. Biol
Conserv 129:487–496
Sollmann R, Furtado MM, Gardner B, Hofer H, Jácomo ATA, Tôrres
NM, Silveira L (2011) Improving density estimates for elusive car-
nivores: accounting for sex-specific detection and movements using
spatial capture–recapture models for jaguars in central Brazil. Biol
Conserv 144:1017–1024
Stander PE (1997) Field age determination of leopards by tooth wear. Afr
J Ecol 35:156–161
Stehlik J (1971) Breeding jaguars at Ostrava Zoo. Int Zoo Yrbk 11:116–118
Sunquist M, Sunquist F (2002) Wild cats of the world. University of
Chicago Press, Chicago
Sussman RW, Cheverud JM, Bartlett TQ (1995) Infant killing as an evo-
lutionary strategy: reality or myth? Evol Anthropol 3:149–151
Tobler MW, Carrilo-Percastegui SE, Hartley AZ, Powell GVN (2013)
High jaguar densities and large population sizes in the core habitat
of the southwestern Amazon. Biol Conserv 159:375–381
Tortato FR, Layme V, Crawshaw PG Jr, Izzo TJ (2015) The impact of
herd composition and foraging area on livestock predation by big
cats in the Pantanal of Brazil. Anim Conserv 18:539–547
Trivers R (1985) Social Evolution. Benjamin/Cummings, Menlo Park, CA
Wilcox R (1992) Cattle and environment in the Pantanal of Mato Grosso,
Brazil, 1870–1970. Agr Hist 66:232–256
acta ethol
Author's personal copy
