Retaining and losing heat
- In bears, the basal metabolic rate varies with climate and season
- Polar Bear has the highest
- Overheat easily when running; can’t travel any great distance at speeds more than a walk.
- Low surface-area to volume ratio favors heat retention.
- Tendency to overheat enhanced by thick layer of fat
- Thin adults and young cubs up to 6 months old, with little body fat, are susceptible to cold.
- Use more than twice the predicted energy for moving at a given speed, perhaps due to bulky body.
- Fat and fur both insulate.
- As long as bear isn’t exposed to wind, body temperature and metabolic rate remain normal at -37 degrees C (-35 degrees F).
- Body temperature drops to 31-35 degrees C (88-95 degrees) when in winter dens; this temperature is only slightly below normal body temperature. (Harrington 1968)
Source: San Diego Zoo wildlife Alliance Library
Manager’s Office Team