Polar Bears Adaptation To The Cold And Hostile Arctic Climate

Polar Bear adaptation to the wintery and hostile Northern climate is one of nature's wonders. The shifting sea ice, where polar bear live, is one of the cruelest and grimmest climates on the globe.

It's only in recent evolutionary time that bears accommodated to arctic sea life. It began around the Ice Age, in the northern seas, when the seals needed to breathe and reproduce at the water's surface. Because of this, the seals became a rich year-round food source near a population of brown bears, who then set out to inhabit the ice, developing into something like the polar bear of today, around 100,000 years ago.

Weighing about 330 to 1,760 pounds, the length of the polar bear's body is approximately 6.6 to 10 feet. The male body is usually bigger than the female. The polar bear, similar to the brown bear, is large and thickset. It has an elongated neck and small head. Its fur, usually white, occasionally appears yellow, due to oxidation.

A polar bear has black skin, which helps it adjust to the Arctic temperature, absorbing and holding heat from the sunlight. It is definitely well attired for the weather with a layer of fat more than 4 inches thick, providing efficient insulation. The dense fur on its feet (its foot is about 9 inches wide and 12 inches long) provides warmth and traction. Since each foot is so big, it acts as a handy snowshoe.

It adjusts well to swimming with its broad feet that serve as paddles and when swimming underwater it lays the small ears flat for protection, and its nostrils close under water. It paddles at about 6 and one-half miles per hour --front feet only, back paws trailing--and can remain under water for about 2 minutes. The hairs of its waterproof coat are hollow which is an adept insulator and increases the bear's buoyancy while swimming.

A polar bear has a keen sense of smell, sensing prey at a distance of about 20 miles. While little is known about its sense of touch (its eyesight and hearing is acute), a polar bear is able to manipulate assorted objects with amazing dexterity.

With canine teeth larger and malariform teeth sharper than those of different bears, the polar bear is the most carnivorous North American bear.

A polar bear inhabits Arctic islands, sea ice, and water and continental coastlines. It prefers the sea ice habitat, with water channels or cracks through the ice, next to continental coastlines or islands. Some polar bears spend part of the year on land, although in warmer climates a bear could become isolated. Most pregnant females spend the autumn and winter on land in maternity dens.

A polar bear moves throughout the year within its home ranges, which are inclined to be a larger area than for other mammal species because of the alterations in sea ice from year to year and even season to season. Small home ranges (19,000 to 23,000 miles) can be found near Canadian Arctic Islands, while bigger home ranges can be seen in the Bering or Chukchi Sea realms. The polar bear stays in the home range area during the same season. A polar bear is capable of traveling 19 miles or more per day for several days, although some are capable of a good deal more than that. One can only hope that polar bear adaptation will persist, as their habitat area shrinks and the pressures of civilization continue to encroach on the the natural homes where the polar bear calls home.