The ecology of the Bush Rat, Rattus fuscipes (Rodentia: Muridae), in Sherbrooke Forest, Victoria.

Abstract

A population of Rattus fuscipes, in Sherbrooke Forest, Victoria, had a well defined breeding season. Mating occurred between November and January and the young were born between December and February. Juveniles were first captured in late February at approximately 1.5 months of age. The subadult age class displaced the parental age class in the population by the following August, so that almost all animals breeding in a season belonged to a single age class. The degree of home range overlap changed seasonally and could be related to changes in the proportion of amicable and agonistic behaviour judged from a series of contrived laboratory encounters. Diet consisted of both plant and insect material and changes in the proportion of these two components correlated with changes in survival. Measurements of 15 physiological parameters and organ weights, drawn at montly intervals indicated three periods during the life cycle when R. fuscipes exhibited heightened adreno-cortical activity. It is suggested that the development of territoriality in subadults during late autumn and possibly the decrease in abundance and quality of food in early winter, largely determine the size of the breeding population in late spring.