No abstract

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. Ecological Society of America is collaborating with JSTOR to digitize, preserve and extend access to Ecology.Abstract. Behavior of white-tailed deer (Odocoileus virginianus) in Itasca Park, northwestern Minnesota, USA was analyzed for energy-conservation adaptations during winter. Track records showed a decrease in activity with an increase in predicted 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 overt 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.

The energy exchange of white—tailed deer in an open field environment under clear winter skies at night is presented. Environmental radiation flux was measured with field instruments; radiation loss and surface temperature of deer were estimated with a simulator; heat loss by convection, evaporation, and warming ingested food was estimated from methods and data reported in the literature for other species. Metabolic heat production at three dietary levels, environmental radiation flux, and the heat loss at air temperatures from 0° to —40°C and wind velocities from ½ to 12 mph at deer height were integrated to provide a quantitative basis for determining the conditions under which thermal stress commences. Calculations are for fawns and does in a standing position in an open field under clear, nocturnal skies. The smaller deer reach a negative energy balance at air temperatures approaching 0°C and wind velocities of ½ to 1 mph if they are on a starvation diet. A maintenance to full diet enables them to withstand higher winds and lower temperatures. The larger deer reach a negative energy balance at air temperatures approaching 0°C and wind velocities of 3 mph when on a starvation diet. A full diet, however, enables them to withstand exposure to ½40°C temperatures and wind velocities of 8 mph. The behavior of the animals on the study area indicated that food rather than cover was of major importance in determining the locations where the deer remained during cold weather. Neither wind nor air temperatures to 35°C forced the deer into the protection of the woodlots. The energy balance predicted from the calculations indicated that these weather conditions should not cause a negative energy balance as long as the food supplied an adequate amount of energy and the deer could seek shelter from wind by moving behind a hill, shrub, or herbaceous vegetation in the open fields.

No abstract