They weigh 700 to 1600 pounds They live on the ice of the Arctic coasts. They eat seals, fish, and walruses. Most female polar bears give birth to two cubs at a time. Cubs are born in a snow den. Polar bears have been known to swim 60 miles (97 kilometers) at a time. Polar bears usually live and hunt alone. In the wild, polar bears live about 25 years. Polar Bears Fur is clear. Polar Bears are Mammals. A mammal has lungs, fur or hair, and gives birth to live young. At birth, polar bear cubs weigh about 454 to 680 grams.