Polar Bears International

© Daniel J. Cox/NaturalExposures.com

Adaptation

The sea bear depends on sea ice.

A polar bear's life cycle is closely tied to sea ice. They rely on the ice to travel, hunt seals, breed, and in some cases, den.  especially in areas that lack alternate marine mammal prey.

Polar bears are strong swimmers and divers, a characteristic that allows them to swim from one ice floe to the next. They also swim underneath thin ice and, as Norwegian researchers recently observed, dive for kelp near shore.

Cold Climate

Arctic weather can be fiercely cold. As humans, we need protective clothing and/or shelter to stay warm. Polar bears don’t. Their bodies thrive in the stark temperatures.

In the High Arctic, the sun sets in October and doesn't rise again until late February. Winter temperatures can plunge to -40° or -46 C (-50 F) and stay that way for days or weeks. The average January and February temperature is -34 C (-29 F).

Bears are insulated with two layers of fur and a thick layer of body fat. This provides enough insulation that their body temperature and metabolic rate doesn’t change, even when temperatures reach -37 C (-34 F).

To learn more about how polar bear’s bodies adjust to their climate, see physical characteristics. A polar bear's body temperature, 37 C (98.6 F), is average for mammals.

© Daniel J. Cox/NaturalExposures.com

On bitterly cold days with fierce winds, polar bears dig shelter pits in snow banks and curl up in a tight ball. Sometimes they cover their muzzles—which radiate heat—with their thickly furred paws and let the snow drift around and over them.

Polar bears have more problems with overheating than they do with cold. That's why they typically walk at a leisurely pace. They can quickly overheat when they run.

Bear Tracker

Watch polar bears as they travel across the sea ice to hunt seals.

Check out Bear Tracker

© Daniel J. Cox/NaturalExposures.com

Polar Bear FAQ

We answer the most frequently asked polar bear questions.

Go to FAQ

Climate Change

A threat to polar bears and the sea ice they depend on.

Learn More

© Daniel J. Cox/NaturalExposures.com