Advantages of habitat selection and sexual segregation in mule and white-tailed deer

Graduation date: 1994I studied sexual segregation in mule deer (Odocoileus\ud hemionus) and white-tailed deer (Q. virginianus) in\ud different environments and at different population\ud densities to test the hypothesis that sexual segregation\ud occurs in ungulates as the result of different\ud reproductive strategies; females select habitat and behave\ud in manners primarily designed to promote offspring\ud survival, while adult males act primarily to maximize\ud energy stores prior to the rut. Data collected for both\ud species were consistent with this hypothesis. Mule deer\ud segregated both socially and spatially. Compared to\ud males, female mule deer used areas that were closer to\ud water, supported superior browse species, and provided\ud greater security for offspring from coyotes. Locally\ud available resources enabled females to minimize movements,\ud the apparent consequence of which was the depletion of\ud forb biomass, the major diet class for both sexes. Males\ud ranged further than females, a strategy that provided a\ud diet high in forbs and high in quality. The occurrence of\ud mixed-sex groups in highly productive areas suggested that\ud males responded to forage availability and not females perse, and that the effects of localized grazing pressure by\ud females may competitively exclude males from areas.\ud Sexual segregation was not maintained by intersexual\ud aggression in either mule or white-tailed deer. White tailed deer segregated socially, but demonstrated broad\ud spatial overlap. During the peak of segregation \ud (June-October), male behaviors were consistent with a pre-rut\ud energy saving and forage seeking strategy; males used\ud larger areas and made longer short term movements than\ud females, but were less active overall and were relatively\ud more active at night. Females were less mobile and\ud foraged in smaller areas than males, particularly during\ud fawn rearing periods (June-October). I also tested the\ud hypothesis that male white-tailed deer segregate and range\ud widely to scout potential mates and rivals. Based upon\ud comparisons of areas used by radio-collared males and\ud females during the peak periods of segregation (June-September) with areas used during the rut, this hypothesis\ud was rejected