THE INFLUENCE OF CLIMATE ON METABOLIC AND THERMAL RESPONSES OF INFANT CARIBOU

Abstract

Metabolic and thermal responses of infant caribou to climate were measured during the June calving period on the barrens in the area of Mosquito Lake and Beverly Lake, N.W.T. It was found that temperature regulation was well established at birth and that the calves were very sensitive metabolically to cold, wind, and precipitation. The metabolic rate was doubled by a lowering of temperature to about 0 °C, but cold combined with wind and precipitation elevated the metabolic rate to over five times the resting value. Calves which were exposed without protection to such conditions eventually became hypothermic and died. Weather conditions during storms on the barrens are sufficiently severe to produce some mortality in animals exposed without protection. The possibilities for prediction of mortality from wind chill values and estimated fur heat loss are discussed.