Polar bears have black skin and although their fur appears white, it is actually translucent, and only appears white because it reflects visible light. Their large paws are specially adapted for swimming, which enables them in the wild, to swim steadily for many hours and cover long distances as they move from one area of ice to another.
Polar bears are the largest land predator in the world and are top of the food chain in the Arctic where their main source of food is seals. A single polar bear can consume 45 kilos of meat at one feeding, and needs about one seal per week, or 50 to 75 seals per year, to survive. They hunt and catch seals by waiting for them to appear at their breathing holes in the ice and by stalking them sunbathing on the ice surface. When the summer arrives and the sea ice retreats, polar bears head towards land to live out the ice free season. During this time, they can go for long periods without eating, surviving mostly off of the fat they accumulated over the winter by eating seal blubber. The females may go without food for four to eight months during the time they enter their den, give birth and arrive back at the sea ice again in the spring.