MOVEMENT OF FEMALE WHITE-TAILED DEER: EFFECTS OF CLIMATE AND INTENSIVE ROW-CROP AGRICULTURE

Abstract

Movements (e.g., migration, dispersal) of white-tailed deer (Odocoileus virginianus) vary greatly over the geographic range of the species. Therefore, region-specific, empirical information is needed to effectively manage deer populations. Movements of white-tailed deer have been well documented in forest dominated habitats; however, little information related to white-tailed deer movements exists in intensively (>80%) cultivated areas. From January 2001 to August 2002, we monitored movements of 77 (61 adult, 16 young) female white-tailed deer in southwest Minnesota. We collected 6,867 locations, calculated 130 home ranges, and documented 149 seasonal movements. Fifteen percent of deer were nonmigratory, whereas 35% were facultative migrators, and 42.5% were obligate migrators. Mean distance between summer and winter home range was 10.1 km. Temperature and snow depth had the greatest influence on initiation of seasonal migration, whereas crop emergence and harvest had minimal effects. Four deer (8%) dispersed a mean distance of 71.3 km with 1 adult female moving a straight-line distance of 205 km. All dispersing deer occupied a temporary staging area for approximately 1 month between previous winter and new summer ranges. Mean home range (95% use area) in winter (5.2 km2) was over twice as large as home range in summer (2.3 km2). Movements exhibited by white-tailed deer in southwest Minnesota were influenced by large annual fluctuations in climate and a highly fragmented landscape dominated by row-crop agriculture. We provide data beneficial to biologists managing northern populations of white-tailed deer in fragmented environments by detailing the relationship between climate, intensive agriculture, and deer movements.