Energetic Cost of Winter Dormancy in Grizzly Bear

Abstract

We investigated overwinter energetics of grizzly bears (Ursus arctos horribilis) by measuring oxygen uptake of 2 bears in a simulated den. Standard metabolic rate averaged 68.0 ? 2.8 (SD)% of predicted values. The lowest observed metabolic rates were further reduced to <50% of expected values. Grizzly bears have the potential to triple survival time on a given level of energy stores through a reduction in metabolic