Energy Conservation by White-Tailed Deer in the Winter

Behavior of white-tailed deer (Odocoileus virginianus) in Itasca Park, north-western Minnesota, USA was analyzed for energy-conservation adaptations during winter. Track records showed a decrease in activity with an increase in perdicted heat loss when activity and heat loss were compared on a sequential basis throughout the winter. Recognition of many seasonal but gradual changes in deer characteristics, such as antler growth, reproductive condition, and molting, suggest that seasonal physiological changes occur and also effect over behavior. Energy may be conserved by reducing the general level of activity, by seeking more level land and lesser snow depths, and by walking more slowly. Such energy-conservation measures may save up to 1,000 kcal/day (= 4,184 kJ/day) for a 60 kg deer, and 0.25-0.50 kg field-weight forage. Deer should remain as undisturbed as possible in the winter; harassment by dogs and snowmobile traffic is counter to their long term physiological and behavioral adaptations.