Complete Polar Bear Facts

Staying Warm - Fur not fat!

Fur Polar bears are covered in fur except for the tip of their nose, and the bottoms of their paws. Their fur is white which makes them more difficult to see when they are standing on white snow - this is called camouflage. Their fur can look pure white or sometimes a little yellow if they have been in the sun. Polar bears also like to lie in seaweed, which can stain their fur a brownish colour. Of course they can also just get dirty from rolling on the ground. To keep warm, a polar bear has two types of fur; a top layer and an under layer. The top layer is made up of long oily hairs which act like a winter jacket does; it is a protective layer to keep the polar bear warm and dry. When a polar bear goes for a swim, the top layer keeps the under layer from getting wet. When the bear is done swimming they can shake off all the water, just like a dog shakes off when it is wet. The under layer is a soft layer of fur that acts like a sweater does. It is thick and wooly, and keeps the bear warm. All the little spaces between the hairs are just like the little spaces between the threads of a person's sweater - they both hold on to warm air, which keeps us (or the polar bear) warm. Each hair also has little spaces to hold more air, which makes polar bear hair very good at keeping polar bears very warm. Air is also very good at making things float. Just like a beach ball floats because there is air inside, the air around a polar bear's fur helps keep the bear floating. It's like they are always wearing a life jacket! In May or June, as the weather starts to get warmer, polar bears start to lose their old fur, and grow new fur for the next winter. They can't buy new clothes, so they grow new fur each year, and shed the old. If you know someone with a cat or a dog, you may have noticed that many cats and dogs shed their fur in the same way. In the early 1980's scientists thought that polar bear fur was like a fiber optic line, but made a very big mistake. Read their Big Guess about polar bear fur.
Fat Polar bear fat can be 10cm (4") thick, but the fat does not provide as much warmth for polar bears as it does for some marine mammals (such as seals). According to well known polar bear researcher, the late Malcolm Ramsey "The blubber under their skin isn't distributed so that it can act as an insulator, it's concentrated in the gut when they're fat,and in the hind limbs. The fat is stored for energy." Their fur and fat are so good at keeping them warm that they have the same body temperature as you do.
Getting too warm The blubber that helps to keep a polar bear warm in winter makes the bear very hot in summer. Imagine wearing your heavy winter clothes in the middle of summer. To keep cool in the summer months, polar bears become very lazy and spread out as much as possible. A swim in the chilly Arctic Ocean will also keep a polar bear cool.
	Snow blankets Snow to stay warm? As a polar bear falls asleep on a snowy day, he or she will become covered in a blanket of snow, and just like there are little air spaces in polar bear fur, there are also air spaces between all the little snow flakes on the ground. O^oC may sound very cold, but it's better than -20^oC. A thick layer of snow will protect the bear from cold temperatures and strong winds. Someties polar bears will dig into a snow bank to sleep and stay warm.