Comfy Nap

Bison adapt to cold by lowering their metabolic rate, requiring less energy and forage. Their dense fur offers such exceptional insulation that snow can accumulate on a bison's insulated back without melting. These and many more adaptations make bison extremely tolerant to cold. In fact, -40°F is the bison's lower critical temperature…the temperature at which they must rely on their metabolism to maintain body temperature.