Polar bear

Polar bear

The Polar bear (Ursus maritimus) is a hypercarnivorous bear whose native range lies largely within the Arctic Circle, encompassing the Arctic Ocean, its surrounding seas and surrounding land masses. It is the largest extant bear species, as well as the largest extant predatory carnivore. A boar (adult male) weighs around 350–700 kg (770–1,540 lb), while a sow (adult female) is about half that size.

Taxonomy

The polar bear was previously considered to be in its own genus, Thalarctos. However, evidence of hybrids between polar bears and brown bears, and of the recent evolutionary divergence of the two species, does not support the establishment of this separate genus, and the accepted scientific name is now Ursus maritimus, meaning "maritime bear".

Characteristics

Polar bears are distinguished by their white fur, which helps them blend into their icy surroundings. They have a thick layer of body fat, which helps them stay warm in the cold Arctic weather. Their paws are wide and large, helping them to distribute their weight on thin ice and snow, and they are excellent swimmers.

Habitat and distribution

Polar bears are found throughout the Arctic, in countries such as Canada, Russia, Greenland, Norway and the United States (specifically Alaska). They are most commonly found along the coasts and on islands, where they can hunt their primary prey, seals.

Conservation status

The polar bear is classified as a vulnerable species by the International Union for Conservation of Nature (IUCN), with eight of the nineteen polar bear subpopulations in decline. For decades, large scale hunting raised international concern for the future of the species but populations rebounded after controls and quotas began to take effect.

See also

• Bear
• Arctic Circle
• Climate change and Arctic wildlife