Australian Journal of Zoology Australian Journal of Zoology Society
Evolutionary, molecular and comparative zoology

Evolution of sexual segregation in mammalian herbivores: kangaroos as marsupial models

G. Coulson A C , A. M. MacFarlane A , S. E. Parsons A B and J. Cutter A

A Department of Zoology, The University of Melbourne, Vic. 3010, Australia.

B Current address: Lower Murray–Darling Catchment Management Authority, Buronga, NSW 2739, Australia.

C Corresponding author. Email:

Australian Journal of Zoology 54(3) 217-224
Submitted: 24 September 2005  Accepted: 24 April 2006   Published: 22 June 2006


Sexual segregation is best known in sexually dimorphic ungulates. Many hypotheses have been proposed to explain the evolution of sexual segregation in ungulates, but all are reducible to the influence of two factors: body size and sex-specific reproductive strategy. Definitive tests of these hypotheses are lacking in ungulates because these factors are confounded, all males being somewhat larger than females. Kangaroos represent a parallel radiation of terrestrial herbivores, but their populations are composed of a spectrum of adult body sizes, ranging from small males the same size as females to large males more than twice the size. We exploited this heteromorphism to assess the independent influences of size and sex in these ungulate analogues. We conducted a preliminary study of western grey kangaroos (Macropus fuliginosus) in north-western Victoria, Australia. Adult males predominately occupied grassland habitat, whereas females occurred mostly in lakebed, woodland and shrubland. Single-sex groups occurred more often than expected during the non-mating season. The diet of large males had the highest proportion of grass, and females had the least. These initial results indicate that both size and sex influence segregation in this species, confirming the worth of kangaroos as marsupial models for research into the evolution of sexual segregation.


Ardia D. R. Bildstein K. L. 1997 Sex-related differences in habitat selection in wintering American kestrels, Falco sparverius. Animal Behaviour 53 1305 1311 DOI

Bank M. S. Sarno R. J. Franklin W. L. 2003 Spatial distribution of guanaco mating sites in southern Chile: conservation implications. Biological Conservation 112 427 434 DOI

Barboza P. S. Bowyer R. T. 2000 Sexual segregation in dimorphic deer: a new gastrocentric hypothesis. Journal of Mammalogy 81 473 489 DOI

Bon R. Campan R. 1996 Unexplained sexual segregation in polygamous ungulates: a defence of an ontogenetic approach. Behavioural Processes 38 131 154 DOI

Bon R. Rideau C. Villaret J. C. Joachim J. 2001 Segregation is not only a matter of sex in Alpine ibex, Capra ibex ibex. Animal Behaviour 62 495 504 DOI

Bonenfant C. Loe L. E. Mysterud A. Langvatn R. Stenseth N. C. Gaillard J.-M. Klein F. 2004 Multiple causes of sexual segregation in European red deer: enlightenments from varying breeding phenology at high and low latitude. Proceedings of the Royal Society of London. Series B. Biological Sciences 271 883 892 DOI

Bowyer R. T. 2004 Sexual segregation in ruminants: definitions, hypotheses, and implications for conservation and management. Journal of Mammalogy 85 1039 1052 DOI

Bowyer R. T. Kie J. G. 2004 Effects of foraging activity on sexual segregation in mule deer. Journal of Mammalogy 85 498 504 DOI

Clutton-Brock T. H. Iason G. R. Guiness F. E. 1987 Sexual segregation and density-related changes in habitat use in male and female red deer (Cervus elaphus). Journal of Zoology 211 275 289

Conradt L. 1998 a Measuring the degree of sexual segregation in group-living animals. Journal of Animal Ecology 67 217 226 DOI

Conradt L. 1998 b Could asynchrony in activity between the sexes cause intersexual social segregation in ruminants. Proceedings of the Royal Society of London. Series B. Biological Sciences 265 1359 1363 DOI

Conradt L. 1999 Social segregation is not a consequence of habitat segregation in red deer and feral Soay sheep. Animal Behaviour 57 1151 1157 DOI

Conradt L. Clutton-Brock T. H. Guinness F. E. 2000 Sex differences in weather sensitivity can cause habitat segregation: red deer as an example. Animal Behaviour 59 1049 1060 DOI

Coulson G. M. 1993 Use of heterogeneous habitat by the western grey kangaroo, Macropus fuliginosus. Wildlife Research 20 137 149 DOI

Coulson G. M. 1997 Repertoires of social behaviour in captive and free-ranging grey kangaroos, Macropus giganteus and Macropus fuliginosus (Marsupialia: Macropodidae). Journal of Zoology 240 119 130

Croft D. B. Snaith F. 1991 Boxing in red kangaroos, Macropus rufus: aggression or play? International Journal of Comparative Psychology 4 221 236

du Toit J. T. 1995 Sexual segregation in kudu: sex differences in competitive ability, predation risk or nutritional needs? South African Journal of Wildlife Research 25 127 132

Ellis B. A. Russell E. M. Dawson T. J. Harrop C. J. F. 1977 Seasonal changes in diet preferences of free-ranging red kangaroos, euros and sheep in western New South Wales. Australian Wildlife Research 4 127 144 DOI

Estes R. D. (1991). ‘The Behaviour Guide to African Mammals. Including Hoofed Mammals, Carnivores and Primates.’ (University of California Press: Berkley, CA.)

Everitt B. S. (1977). ‘The Analysis of Contingency Tables.’ (Chapman and Hall: London.)

Ginnett T. F. Demment M. W. 1999 Sexual segregation by Masai giraffes at two spatial scales. African Journal of Ecology 37 93 106 DOI

Green S. W. Renfree M. B. 1982 Changes in the milk proteins during lactation in the tammar wallaby, Macropus eugenii. Australian Journal of Biological Sciences 35 145 152

Jaremovic R. V. Croft D. B. 1991 Social organisation of eastern grey kangaroos in southeastern New South Wales. II. Associations within mixed groups. Mammalia 55 543 554

Jarman P. J. 1983 Mating system and sexual dimorphism in large, terrestrial, mammalian herbivores. Biological Review 58 484 520

Jarman P. J. 1991 Social behaviour and organization in the Macropodoidea. Advances in the Study of Behaviour 20 1 50

Jarman P. J., and Coulson G. (1989). Dynamics and adaptiveness of grouping in macropods. In ‘Kangaroos, Wallabies and Rat-kangaroos’. (Eds G. Grigg, P. Jarman and I. Hume.) pp. 527–547. (Surrey Beatty: Sydney.)

Jarman P. J., and Phillips C. M. (1989). Diets in a community of macropod species. In ‘Kangaroos, Wallabies and Rat-kangaroos’. (Eds G. Grigg, P. Jarman and I. Hume.) pp. 143–149. (Surrey Beatty: Sydney.)

Jarman P. J., and Southwell C. J. (1986). Grouping, associations, and reproductive strategies in eastern grey kangaroos. In ‘Ecological Aspects of Social Evolution’. (Eds D. I. Rubenstein and R. W. Wrangham.) pp. 399–428. (Princeton University Press: Princeton, MA.)

Kaufmann J. H. 1975 Field observations of the social behaviour of the eastern grey kangaroo, Macropus giganteus. Animal Behaviour 23 214 221 DOI

Le Pendu Y. Guilhem C. Briedermann L. Maublanc M.-L. Gerard J.-F. 2000 Interactions and associations between age and sex classes in mouflon sheep (Ovis gmelini) during winter. Behavioural Processes 52 97 107 DOI

Lei R. H. Jiang Z. G. Liu B. W. 2001 Group pattern and social segregation in Przewalski’s gazelle (Procapra przewalskii) around Qinghai Lake, China. Journal of Zoology 255 175 180 DOI

MacFarlane A. M., and Coulson G. (2005). Sexual segregation in Australian marsupials. In ‘Sexual Segregation in Vertebrates: the Ecology of the Two Sexes’. (Eds K. E. Ruckstuhl and P. Neuhaus.) pp. 254–279. (Cambridge University Press: Cambridge.)

Main M. B. Weckerly F. W. Bleich V. 1996 Sexual segregation in ungulates: new directions for research. Journal of Mammalogy 77 449 461

Miquelle D. G. Peek J. M. Van Ballenberghe V. 1992 Sexual segregation in Alaskan moose. Wildlife Monographs 122 1 57

Norbury G. L. (1987). Diet selection and demography of the western grey kangaroo, Macropus fuliginosus melanops (Desmarest) in Hattah-Kulkyne National Park, Victoria. Ph.D. Thesis, Monash University, Melbourne.

Norbury G. L. 1988 Microscopic analysis of herbivore diets – a problem and a solution. Australian Wildlife Research 15 51 57 DOI

Norbury G. L. Coulson G. M. Walters B. L. 1988 Aspects of the demography of the western grey kangaroo, Macropus fuliginosus melanops, in semi-arid north-west Victoria. Australian Wildlife Research 15 257 266 DOI

Pellegrini A. D. Long J. D. 2003 A sexual selection theory longitudinal analysis of sexual segregation and integration in early adolescence. Journal of Experimental Child Psychology 85 257 278 DOI

Poole W. E. 1975 Reproduction in the two species of grey kangaroo, Macropus giganteus Shaw and M. fuliginosus (Desmarest). II. Gestation, parturition and pouch life. Australian Journal of Zoology 23 333 353 DOI

Priddel D. 1986 The diurnal and seasonal patterns of grazing of the red kangaroo, Macropus rufus, and the western grey kangaroo, M. fuliginosus. Australian Wildlife Research 13 113 120 DOI

Ruckstuhl K. E. 1998 Foraging behaviour and sexual segregation in bighorn sheep. Animal Behaviour 56 99 106 DOI

Ruckstuhl K. E. 1999 To synchronise or not to synchronise: a dilemma for young bighorn males. Behaviour 136 805 818 DOI

Ruckstuhl K. E. Festa-Bianchet M. 2001 Group choice by subadult bighorn rams: trade-offs between foraging efficiency and predator avoidance. Ethology 107 161 172 DOI

Ruckstuhl K. E. Neuhaus P. 2000 Sexual segregation in ungulates: a new approach. Behaviour 137 361 377 DOI

Sluiter I. R. K., Allen G. G., Morgan D. G., and Walker I. S. (1997). Vegetation responses to stratified kangaroo grazing pressure at Hattah-Kulkyne National Park, 1992–96. Flora and Fauna Technical Report No. 149. Department of Natural Resources and Environment, Melbourne.

Stewart B. S. 1997 Ontogeny of differential migration and sexual segregation in northern elephant seals. Journal of Mammalogy 78 1101 1116

Storr G. M. 1961 Microscopic analysis of faeces, a technique for ascertaining the diet of herbivorous mammals. Australian Journal of Biological Sciences 14 157 165

Weckerly F. W. 1998 Sexual-size dimorphism: influence of mass and mating systems in the most dimorphic mammals. Journal of Mammalogy 79 33 52

Wielgus R. B. Bunnell F. L. 1995 Tests of hypotheses for sexual segregation in grizzly bears. Journal of Wildlife Management 59 552 560

Export Citation Cited By (9)