If climatic trends continue, polar bears will be gone from most of their range within 100 years. The current worldwide population of 20,000 to 25,000 is projected to rapidly decline. Polar bears were listed as a threatened species across their range under the Endangered Species Act in May of 2008 because of the melting of their sea ice habitat. In the wild, polar bears live an average of 15 to 18 years, although biologists have tagged a few bears that were in their early 30s. Throughout the Arctic, polar bears are known by a variety of common names, including nanook, nanuq, ice bear, sea bear, isbjorn, white bears, and beliy medved. Her milk is very rich, with about 31% fat (compared to 3.5% in whole cow's milk), so the cubs grow rapidly. Their large webbed paws help make them excellent swimmers. POLAR BEAR SKINThey have black skin to better absorb heat and thick white coats that repel water and provide camouflage in the snow and ice. They are completely dependent on their mother for warmth and food, and they will typically stay with her until they are two and a half years old. A polar bear’s home is on the sea ice, where it hunts seals at open leads and breathing holes. Polar bears ( Ursus maritimus) are closely related to brown bears but have adapted to life in the snow and ice and live in the coldest environments in the nation. Newborn cubs are 12 to 14 inches long and weigh only about a pound. She doesn't eat this entire time, so when she emerges from the den, she will have lost all of her extra body weight. It grows to about 1.6 metres (5.3 feet) tall at the shoulder and 2.22.5 metres in length. The male, which is much larger than the female, weighs 410 to 720 kg (900 to 1,600 pounds). Eventually she digs a snow cave called a "maternity den," where she spends the next 5 months, first giving birth, then nursing her cubs. Polar bears are stocky, with a long neck, relatively small head, short, rounded ears, and a short tail. Because a bear might lose the embryo if she doesn't put on enough fat, the female eats enough in the early months of her pregnancy to double her body weight. In this way, polar bears are able to concentrate on high-calorie fat when food is plentiful and pack on the pounds.įemales are pregnant for 8 months. When food is plentiful, they eat only the skin and blubber and leave the rest of the carcass for Arctic foxes and other animals. They prefer ringed seals, but they also eat bearded, harp, and hooded seals.
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