The Polar Bear (Ursus maritimus) is a species of bear that lives in the Arctic, found in places such as Alaska, Canada, Greenland, Norway, Iceland and Russia. It is the largest and most powerful species of bear and is the largest of all carnivorous land mammals.
Polar bears are thought to have diverged from a population of brown bears that became isolated during a period of glaciation in the Pleistocene from the eastern part of Siberia (from Kamchatka and the Kolym Peninsula).
Although it is the sister species of the brown bear, it has evolved to occupy a narrower ecological niche, with many body characteristics adapted for cold temperatures, for moving across snow, ice and open water, and for hunting seals, which make up most of its diet. Although most polar bears are born on land, they spend most of their time on the sea ice. 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 is present. Because of their dependence on the sea ice, polar bears are classified as marine mammals.
Because of expected habitat loss caused by climate change, the polar bear is classified as a vulnerable species. For decades, large-scale hunting raised international concern for the future of the species, but thankfully populations have rebounded after controls, conservation measures and quotas began to take effect, though climate change is still a big threat at large for the bears. For thousands of years, the polar bear has been a key figure in the material, spiritual, and cultural life of circumpolar peoples, and polar bears remain important in their cultures. Historically, the polar bear has also been known as the "white bear". It is sometimes referred to as the "nanook", based on the Inuit term nanuq.
The polar bear is the apex predator within its home range, with seals making up the bulk of their diet. Ringed and bearded seals are their favorite prey. The polar bear is a keystone species for the Arctic. Several animal species, particularly Arctic foxes and glaucous gulls, routinely scavenge on polar bear kills. Their preferred method of hunting seals would usually be to wait by a seal breathing hole and quickly snatch and kill any seal coming up for air with their jaws. Its diet also includes walruses, beluga whales, narwhals, reindeer, musk oxen, bird eggs and chicks, and fish like the Arctic char.
Polar bears are incredibly powerful animals, with a bite force of 1200 PSI (one of the most powerful of any land predator), paws powerful enough to smash a seal's skull or rip a man's head off, razor sharp claws, powerful canine teeth and jaws, as well as a muscular build with powerful limbs. They can run at 25 mph over short bursts, have great amounts of stamina overall and can swim at 6 mph. One polar bear was recorded swimming in the Arctic Ocean for 220 miles for almost 10 days without rest.
These iconic bears have evolved for life in the cold Arctic, with features like thick layers of blubber for warmth and protection, translucent fur with hollow insides for trapping warm air for keeping warm further as well as having black colored skin, sharp claws and gripping paw pads for walking on ice. They also have keen senses of sight, smell and hearing, especially their sense of smell which is one of the best in the animal kingdom. They can smell and track prey from up to 5.6 miles away.