© 1974 by The Society for Integrative and Comparative Biology
The Ecology and Evolution of Social Organization in the Kangaroo Family (Macropodidae)
Zoology Department, University of Florida Gainesville, Florida 32611
Approximately 45 species of kangaroos and their smaller relatives occupy virtually every terrestrial habitat in Australia. The most social macropod is the whiptail wallaby, which lives in permanent, discrete mobs of up to 50 individuals of mixed age and sex. Group formation is facilitated by their grazing habits, open forest and pasture habitat, partly diurnal activity, and low level of intraspecific aggressiveness. Pressure from cursorial predators, plus the whiptail's non-seasonal breeding and brief estrus, make group living adaptive. Ancestral macropods are believed to have been rabbit-sized inhabitants of dense forest, omnivorous, nocturnal, and essentially solitary. The major evolutionary trends in the family have been toward larger size and grazing habits; the trends toward diurnality and group living have had more modest results. Progressive stages in macropod social evolution may be represented by the present-day musk rat-kangaroo, the quokka, and the whiptail wallaby.