Home range of the allied rock-wallaby, Petrogale assimilis

Abstract

The home range and movements of the allied rock wallaby, Petrogale assimilis, a small macropod of the seasonally wet-dry tropics of Queensland, were studied over a 22-month period. There was no significant difference in the size of home ranges (95% isopleth) or core areas (65% isopleth) of males and females. Home ranges were generally elliptical with a mean size of 11.9 ha. Season had a major effect on home ranges. The following measures were all significantly greater in the dry seasons than in the wet seasons: home-range size (larger), home-range shape (more elongate), distance moved by females when feeding (longer), distance between shelter site and home-range centre of activity (longer). Feeding movements of males did not vary seasonally and were as long as dry-season movements of females, suggesting that movements of males are primarily determined by behavioural rather than physiological considerations. The overlap of rock-wallaby home ranges varied little between the sexes or seasons and averaged 38%. Core areas overlapped by an average of 22%; however, feeding adult rock-wallabies rarely met other conspecifics, except their partners. A comparison of the fixes of unpaired wallabies that had overlapping home ranges showed that temporal separation was occurring. In contrast, the home ranges of consort pairs showed extremely high temporal and spatial overlap. Rock-wallabies exhibited strong fidelity to their home ranges. The overlap of the seasonal home ranges and core areas of each individual rock wallaby averaged 68% and 52%, respectively. However, the seasonal home range of a socially immature adult male altered in location and size as he matured socially until it stabilised when he obtained a permanent consort.