THE EFFECTS OF AGE, SEX, REPRODUCTIVE STATUS AND TEMPORAL FACTORS ON THE TIME-USE OF FREE-RANGING RED KANGAROOS (MACROPUS-RUFUS) IN WESTERNNEW-SOUTH-WALES

The effects of temporal (time of day and season) factors and size, sex , female reproductive state and group size on the diel time-use of fre e-ranging red kangaroos (Macropus rufus) was examined. Particular emph asis was given to the effects on their foraging behaviour, with foragi ng divided into cropping, chewing and searching components. The study was conducted in semi-arid western New South Wales from July 1991 to M arch 1992, a time of deepening drought conditions in New South Wales. Group size had very little influence on the time-use of M. rufus. It w as negatively but only weakly correlated with the proportion of foragi ng time spent chewing (chewing intensity). No significant differences in time-use were found between size classes of adult males (large and medium-sized males), females with or without pouch young, or females w ith different-sized pouch young (no visible young, small pouch young o r large pouch young). Differences occurred between adult males, adult females and subadult kangaroos. These differences were mainly associat ed with their chewing and searching behaviour and were related to body size; as body size increased the proportion of time spent chewing and the intensity of chewing increased while the proportion of time searc hing and the proportion of foraging time spent searching (searching in tensity) decreased. Neither the proportion of time spent cropping or f oraging nor the proportion of foraging time spent cropping (cropping i ntensity) or the proportion of active time spent foraging (foraging in tensity) differed between any size/sex/reproductive class. Temporal ef fects had a considerable influence on time-use. M. rufus were most act ive at night and in the few hours after sunrise and sunset. Seasonal c hanges in time-use were largely a result of changes in daytime behavio ur. M. rufus foraged less and rested more during the day in winter tha n in spring or summer. There was no increase in the intensity or propo rtion of time spent foraging or cropping at night to compensate for th e reduction in diurnal foraging. It is hypothesised that temporal vari ations in time-use were related to variations in weather and vegetatio n conditions.