Discontinued, Limited Supply Available! Interior: Earth Polar Bear Minutiae Scientists believe that Ursus maritimus, the "sea bear," evolved about 200,000 years ago from brown bear ancestors. Range throughout the Arctic. The five "polar bear nations" are the U.S. (Alaska), Canada, Russia, Norway, and Denmark/Greenland. World's largest land predators They top the food chain in the Arctic, where they prey on seals. Will also eat berries, grasses, eggs, ducks, geese, lemmings, reindeer, seaweed, walrus, certain whales, and sometimes other polar bears. Can consume 100 pounds of blubber at one sitting. Good eyesight and keen sense of smell. They can smell food from great distances and can sniff out seal dens covered by thick layers of snow and ice. Fastidious about staying clean. After feeding, will devote up to fifteen minutes to grooming. A thorough job is important as matted and dirty fur is a poor insulator. From nose to tail, adult males measure from 7.5 to 8.5 feet long. Some weigh more than 1,300 pounds. Most adult females are about 6.5 feet long and weigh 330 to 550 pounds. A thick layer of blubber (up to 4.5 inches thick) provides them with such excellent insulation that their body temperature and metabolic rate remain the same even at -34°F. Compact ears and small tail also help prevent heat loss. Body temperature is 98.6°, which is average for mammals. Have more problems with overheating than they do with cold. Even in very cold weather, they quickly overheat when they try to run. Excellent swimmers, although they paddle with only their front paws and cannot dive deeply. On a solid surface, they can run for short bursts at speeds of up to 25 miles an hour. Though brown and black bears hibernate in winter, polar bears do not. Only pregnant females hole up in a den. The rest of the population remains active throughout the year. A pregnant female will usually occupy a den from October to March or April. In late November or early December, she gives birth to one to three young—usually twin cubs. At birth, cubs are blind and weigh 1.5 lbs. The mother nurses her cubs until they weigh about 22 lbs. and are strong enough to follow her while she hunts. Most cubs stay with their mother for 2.5 years. Live up to 33 years in the wild and a bit longer in captivity. Rarely kill people, but humans threaten their survival through pollution and hunting. Global warming also reduces the ice on which they live and hunt, threatening their survival. The IUCN lists global warming as their greatest threat. Laws protect them in all nations where they live. On May 14, 2008, the U.S. Department of the Interior listed the polar bear as a threatened species under the Endangered Species Act.
