Does home range of the black-tailed tree rat (Thallomys nigricauda Thomas 1882) change with season along an aridity gradient?

Abstract

Home-range size may reflect the physiological state and energetic requirements of an individual. In the black-tailed tree rat (Thallomys nigricauda) we expected differences in the home-range size of populations in habitats of differing productivity, as measured along an aridity gradient, and between seasons.We studied the variations in home-range size of black-tailed tree rats by radiotracking in winter 2006, 2007 and summer 2007 at three study sites along an aridity gradient in southern Africa. Home ranges were estimated using 100% and 95% minimum convex polygons (MCP) and 95% and 50% fixed kernels. Home ranges varied widely, from 166 to 80 199m2 for males and from 46 to 8810m2 for females. Males had larger home ranges than females, which supports a promiscuous mating system reported for the species. Although range size was reduced in both sexes in winter, this was not significant.We found no significant difference in home-range size along the aridity gradient. It is suggested that a combination of habitat productivity, season and breeding system influences the size of home range and that this species displays phenotypic flexibility in terms of its behavioural responses to these factors.

African Zoology 45(2): 177–188 (October 2010)