TIME-BUDGET VARIATIONS IN RELATION TO DENSITY-DEPENDENT SOCIAL INTERACTIONS IN FEMALE AND YEARLING MALE FALLOW DEER DURING THE RUT

We investigated time-budget variations among female and yearling (soci ally immature 1.5-year-old) male fallow deer (Dama dama) during the ru tting season in six captive populations in central Sweden. The effects of population density, male density, and operational sex ratio on tim e budgets were analyzed. Although no differences were apparent before the rut, populations differed in the time budgets of females and yearl ing males during the rut. During this period, the time spent by female s in feeding and resting activities of yearling males decreased with i ncreasing population density, whereas feeding and resting activities o f yearling males decreased with increasing male density. Behaviour of adult males during the rut and interactions of adult males with other animals appeared to be the principal factors affecting the time budget s of both females and yearling males. Our results show that density-de pendent effects may occur through social interactions alone, regardles s of the effects on resource depletion. The decrease in the proportion of time spent in restoring (lying and grazing) behaviours represents an energy cost for both females and young males. Given the timing of t he rut just before the winter, this cost may negatively effect the con dition of individuals.