Animal Adaptations What Goes Where? Adaptations in Bears

Polar Bears

Polar bears are well-adapted to severe cold. Winter temperatures in the far north often plunge to -40° F or -50° F and can stay that way for days or even weeks. On bitterly cold days with fierce winds, polar bears dig out a shelter in a snow bank and curl up in a tight ball to wait out the storm. When curled up in a ball, polar bears sometimes cover their muzzles -- which radiate heat -- with one of their thickly furred paws.

The polar bear's compact ears and small tail also help prevent heat loss. Polar bears have two layers of fur for further protection from the cold.

The polar bear's fat layer, which is three to four inches thick, not only protects it from the cold, but adds to its bouyancy in the water. A polar bear is so well-insulated that it experiences almost no heat loss. In addition to its insulating fur, the bear's blubber layer can measure 4.5 inches thick.

A polar bear's forepaws are partially webbed to assist it in swimming. The massive size of the forepaws help as well. Each measures up to 12 inches in diameter.

The polar bear's paws are superbly adapted to navigating in the Arctic. Each paw measures up to 12 inches across (31 centimeters). The polar bear's large paws help distribute the animal's weight when it is treading on thin ice. Polar bears have black footpads on the bottom of each paw. The pads are covered by small, soft bumps known as papillae. The papillae grip the ice and keep the bears from slipping. Tufts of fur grow between the polar bear's toes and footpads. Like the papillae, the fur helps to keep the bears from slipping.

A polar bear's claws are thick and curved. Each can measure more than two inches (5.1 centimeters) long. The polar bear's sharp, strong claws help the animal catch and hold its prey. The claws also provide traction on the ice. The polar bear's large paws are designed for use in the water as well as on the ice. The forepaws serve as large paddles when the bears are swimming, while the hind paws serve as rudders.

Grizzly Bears

Grizzlies often dig beneath the roots of large trees to create their dens. Grizzlies are omnivores, meaning they eat both plants and other animals. Their diet varies by the season and includes grasses, roots, berries, nuts, fish and rodents. Aided by their long front claws and massive shoulder muscles, grizzlies are excellent diggers. Grizzlies also eat a great deal of insects, sometimes tearing rotten logs apart and turning over heavy stones in search of insects.

Black Bear Black bears have short, sharp claws to help them climb trees to escape predators. Black bears like to eat berries, nuts, and insects – especially bees.