Effects of parturition on home ranges and social affiliations of female white-tailed deer

The effects of parturition, contraceptive treatment, and a buck harvest on home range sizes and social affiliations of 48 female white-tailed deer (Odocoileus virginianus) were studied in a 176-ha enclosure in southern Connecticut. Population density was reduced from 68 deer/km(2) to 39 deer/km(2) in late 1992 through removal of 51 bucks. The male:female sex ratio changed from 3:2 to 1:2. Concurrently, 24 does were treated with experimental contraceptives. Kernel home ranges enclosing 95 and 50% of each doe's utilization distribution were calculated for 2 6-week periods following parturition in 1992 (pre-harvest), and 4 6-week periods in 1993 (post-harvest): 1 period before and 3 periods following parturition. Mean home range size and frequency of association with other does were significantly greater following the harvest. Lactating does occupied smaller home ranges than non-lactating does only in the post-harvest year. Lactating does associated with other does less frequently than did non-lactating does in all periods and both years. Frequency of association was lowest during the first 6 weeks following parturition. The proportion of significant social interactions between pairs of does did not change between years. Contraceptive treatment had no effect on home range size, but led to a lower frequency of social affiliations. Our results indicate parturition led to smaller home ranges and lowered sociability among does with fawns for 6 weeks pre-partum and 12-18 weeks postpartum in the post-harvest year, but these effects were partly masked in the pre-harvest year, when population density was highest.