The polar bear’s Latin name, Ursus maritimus, means “sea bear.” It is the only bear considered a marine mammal, because it depends upon the marine environment for survival. Being the largest land carnivore in North America, it is distinguished from other types of bears by its long body, neck and skull, and its white hollow-haired coat
The polar bear is well-adapted to life in the extremes of the Arctic. Its distinctive white colour acts as camouflage in the snow and ice, enabling it to stalk seals and hide from human hunters. Its thick coat has glossy guard hairs and a dense underfur. As well, an insulating layer of fat beneath the skin helps to keep the polar bear warm. The polar bear’s feet have small bumps and cavities on the sole, providing traction and preventing it from slipping on icy terrain.
It has large canine teeth and grinding surfaces on its cheek teeth. Large, strong paws assist the hunting of seals in holes in the ice, further aided by claws that are sharp, straight and non-retractable.
Habitat and behaviour
The polar bear spends most of its time patrolling vast areas of ocean ice surrounding open water. It uses the ice as a platform to hunt ringed seal — the most common seal found in the Arctic. When hunting, the polar bear uses its sense of smell and also preys on other types of seals such as the bearded seal, beluga, narwhal and, occasionally, walrus.
During periods when food is less available, the polar bear has the ability to slow down its metabolism. It will do this after 7 to 10 days of no food as a way to conserve its energy and can sustain this state until food becomes available again. The bears will do this when the weather is the warmest, in the summer, or the coldest, in the winter.
The polar bear is an excellent swimmer. A buoyant layer of fat helps it stay warm in the frigid Arctic water. Its powerful front paws are like paddles and its rear paws trail behind and act as rudders. It has been known to swim up to 10 kilometres per hour and for more than 200 kilometres without a rest. It is also able to hold its breath for more than a minute underwater.
Canada is one of five “polar bear nations,” along with the United States (Alaska), Russia, Denmark (Greenland) and Norway. While the polar bear population worldwide is estimated to be between 20,000 and 25,000, approximately 13,000 to 15,000 live in Canada.
The polar bear is found in Canada from James Bay to northern Ellesmere Island and from Labrador to the Alaskan border. Churchill, Man., on the west coast of Hudson Bay, is one of the three largest polar bear maternity denning areas in the world.
A polar bear’s territory depends on the breakup and freezing patterns of the sea ice and on the bear’s ability to travel the ice floes in search of food. When it has access to ice and seals, the polar bear does not need to travel far, and its territory is relatively small. But the bear’s range can vary from about 500 square kilometres covered in a year to around 600,000 square kilometres. A normal range is anywhere from 100,000 to 150,000 square kilometres.