Polar bears are marine mammals, and spend much of their time on Arctic sea ice. Many adaptations make polar bears uniquely suited to life in icy habitats. Their fur is thicker than any other bears’ and covers even their feet for warmth and traction on ice. A thick layer of blubber beneath their fur provides buoyancy and insulation. The long neck and narrow skull of the polar bear probably aid in streamlining the animal in the water while warming the air that they breathe, and their front feet are large, flat and oar-like, making them excellent swimmers.The most carnivorous of the bear species, polar bears feed primarily on the fat of ice-dependent seals. The remains of these seals provide food for many other Arctic wildlife species, giving polar bears a vital role in their ecosystem.
The World Conservation Union (IUCN) estimates that there are between 20,000-25,000 polar bears in the world. As the sea ice advances and retreats each season, individual polar bears may travel thousands of miles per year to find food. Polar bears are distributed throughout the Arctic region in 19 subpopulations, including Alaska, Canada, Russia, Greenland and Norway. Due to changes in climate, their icy habitats are shrinking, and many of their homes are melting. The National Wildlife Federation reports that polar bears simply can’t adapt to temperatures above 50 degrees.