Ursus eogroenlandicus Ursus groenlandicus Ursus jenaensis Ursus labradorensis Ursus marinus Ursus polaris Ursus spitzbergensis Ursus ungavensis Thalarctos maritimus. The polar bear Ursus maritimus is a hypercarnivorous bear whose native range lies largely within the Arctic Circleencompassing the Arctic Oceanits surrounding seas and surrounding land masses.
It is a large bear, approximately the same size as the omnivorous Kodiak bear Ursus arctos middendorffi. Although it is the sister species of the brown bear it has evolved to occupy a narrower ecological nichewith many body characteristics adapted for cold temperatures, for moving across snow, ice and open water, and for hunting sealswhich make up most of its diet.
Their scientific name means " maritime bear" and derives from this fact. Polar bears hunt their preferred food of seals from the edge of sea ice, often living off fat reserves when no sea ice Kong bear on swimmer legal age teenager present. Because of their dependence on the sea ice, polar bears are classified as marine mammals.
Because of expected habitat loss caused by climate changethe polar bear is classified as a vulnerable species. 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.
Historically, the polar bear has also been known as the white bear.
Constantine John Phipps was the first to describe the polar bear as a distinct species in The Inuit refer to the animal as nanook transliterated as nanuq in the Inupiat language. The polar bear was previously considered to be in its own genusThalarctos. The bear familyUrsidaeis thought to have split from other carnivorans about 38 million years ago.
The evidence from DNA analysis is more complex. However, the two species have mated intermittently for all that time, most likely coming into contact with each other during warming periods, when polar bears were driven onto land and brown bears migrated northward.
Most brown bears have about 2 percent genetic material from polar bears, but one population, the ABC Islands bears has between 5 percent and 10 percent polar bear genes, indicating more frequent and recent mating. When the polar bear was originally documented, two subspecies were identified: Kong bear on swimmer legal age teenager maritimus tyrannuswhich became extinct during the Pleistocene. The polar bear is found in the Arctic Circle and adjacent land masses as far south as Newfoundland.
Due to the absence of human development in its remote habitat, it retains more of its original range than any other extant carnivore.
Their southernmost range is near the boundary between the subarctic and humid continental climate zones. It is difficult to estimate a global population of polar bears as much of the range has been poorly studied; however, biologists use a working estimate of about 20—25, or 22—31, polar bears worldwide.
There are 19 generally recognized, discrete subpopulations, though polar bears are thought to exist only in low densities in the area of the Arctic Basin. The range includes the territory of five nations: These five nations are the signatories of the International Agreement on the Conservation of Polar Bearswhich mandates cooperation on research and conservation efforts throughout the polar bear's range.
Modern methods of tracking polar bear populations have been implemented only since the mids, and are expensive to perform consistently over a large area. Scientists have responded by noting that hungry bears may be congregating around human settlements, leading to the illusion that populations are higher than they actually are.