Spatiotemporal variations in resources affect activity and movement patterns of white-tailed deer (Odocoileus virginianus) at high density

Abstract

Although activity budget, movements, and habitat use of herbivores have been extensively studied, few studies have simultaneously examined these behaviors at several temporal scales. We investigated the influence of spatiotemporal variations in forage and climate on the activity and movement patterns of white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) at high density, in a predator-free ecosystem impacted by long-term browsing. We used GPS telemetry and activity sensors to monitor seasonal activity budgets, movements, and patterns of habitat use within the home ranges of 24 female deer at three temporal scales: (1) season, (2) within season, and (3) daily. At large temporal scale, deer were less active and moved less during winter than during summer. Within each season, deer reduced their activity and movements in areas where forage resources were abundant and when climatic conditions were more difficult. On a daily scale, summer and winter movements peaked at dusk, but habitat selection neither changed with period of the day nor activity (foraging vs. resting). These results provide empirical evidence on how environmental constraints can modulate the trade-offs between forage acquisition and exposure to limiting factors.