Variability in grouping in the Eastern grey kangaroo, Macropus giganteus. II: Dynamics of group formation

The effects of season, population density and habitat on aspects of group formation in the eastern grey kangaroo were examined. The rate at which groups join and split increased exponentially with population density, but did not vary with season or habitat. In general, large males and females with young-at-foot were seen alone more frequently than small males, females with pouch young or females with no young. The high frequency oflone large males may be due to a tendency to move alone from one group to another to check the oestrous condition of females, but females with young-at-foot appear to be relatively solitary. Association among population classes in groups of two or more was highly variable.