POLAR BEAR

Polar bear (Ursus maritimus) also called White Bear, Water Bear, Sea Bear, or Ice Bear (Ursus maritimus, formerly Thalarctos maritimus), semiaquatic northern bear, family Ursidae, found throughout Arctic regions, generally on drifting oceanic ice floes. The polar bear is sought for its trophy value and (especially by Eskimo) for its hide, tendons, fat, and flesh; the liver, however, is inedible and often poisonous because of its high vitamin A content. Since 1973 the polar bear has been protected by an international agreement that allows hunting of polar bears only by local populations using traditional weapons. Camouflaged against ice and snow by its whitish fur, the polar bear is a swift and wide-ranging traveler. It swims very well and is often found many miles from land or ice packs. The polar bear stalks and captures its primary prey, the seal, whose southward migrations it may follow as far south as the Gulf of St. Lawrence in Canada and the mouth of the Amur River in Russia. It supplements its diet with fish, seaweed, grass, birds, caribou, and the occasional stranded whale. The male polar bear, which is usually larger than the female, ranges in weight from about 410 to 720 kg (about 900 to 1,600 pounds). It grows to about 1.6 m (5.3 feet) at the shoulder and 2.22.5 m in length (also having a tail of 712 cm [34 inches]). The hairy soles of the polar bear's broad feet protect and insulate it from the cold and also facilitate movement across the ice. An elongated neck supports its relatively small head. The polar bear is usually shy but is dangerous when confronted or attacked. One to four (usually two) cubs are born in winter, in a den of ice or snow, after a gestation period of 240270 days. Cubs weigh about 1 kg at birth and remain with their mother for 10 months to 2 years.