Thursday 24 December 2009

Polar Bears


The polar bear (Ursus maritimus) is a bear native largely within the Arctic Circle encompassing the Arctic Ocean, its surrounding seas and surrounding land masses. It is the world's largest carnivore species found on land. It is also the largest bear, together with the omnivore Kodiac bear which is approximately the same size. An adult male weighs around 350–680 kg (770–1,500 lb), while an adult female is about half that size. Although it is closely related to the brown bear, it has evolved to occupy a narrow ecological niche, with many body characteristics adapted for cold temperatures, for moving across snow, ice, and open water, and for hunting the seals which make up most of its diet. Although most polar bears are born on land, it spends most of its time at sea, hence its name meaning "maritime bear", and can hunt consistently only from sea ice, spending much of the year on the frozen sea.
The polar bear is classified as a vulnerable species, with 5 of the 19 polar bear subpopulations in decline. For decades, unrestricted hunting raised international concern for the future of the species; populations have rebounded after controls and quotas began to take effect. For thousands of years, the polar bear has been a key figure in the material, spiritual, and cultural life of Arctic indigenous
peoples, and the hunting of polar bears remains important in their cultures.
The IUCN now lists global waming as the most significant threat to the polar bear, primarily because the melting of its sea ice habitat reduces its ability to find sufficient food. The IUCN states, "If climatic trends continue polar bears may become extirpated from most of their range within 100 years." On 14 May 2008, the United States Department of the Interior listed the polar bear as a threatened species under the Endangered Speices Act.
Being both curious animals and scavengers, polar bears investigate and consume garbage where they come into contact with humans. Polar bears may attempt to consume almost anything they can find, including hazardous substances such as strofoam, plastic, car batteries, ethylene glycol, hydraulic fluid, and motor oil. The dump in Churchill, Manitoba was closed in 2006 to protect bears, and waste is now recycled or transported to Thompson, Manitoba. To see just how far polar bears have come in integrating with humans take a look at the picture below: