Discover the surprising truth about polar bear skin and fur.
The answer to this question seems obvious: Polar bears are white. But as is often the case in the animal kingdom, the obvious answer is not the correct one. Despite their ability to blend in with their snowy Arctic environment, polar bears actually have black skin beneath their fur. Even more interesting, their fur isn't actually white -- it's transparent, made up of hollow-tubed hairs that help trap heat from the sun's rays.
With a thick layer of blubber designed to maintain body heat, black skin that absorbs sunlight, and two layers of heat-trapping fur, polar bears boast a physiology designed to keep them toasty even in the most extreme temperatures. Polar bears are so well insulated that they are rendered invisible under the lens of an infrared camera.
Measuring up to 10 feet tall and weighing on average a half-ton, polar bears rule the Arctic food chain, feasting on a diet consisting primarily of seals (with a few whales, reindeer and walruses mixed in for variety).
Unfortunately, even the undisputed king of the great white North is unable to withstand the overwhelming force of global warming. According to conservationists, climate change and reduced ice shelves in the Arctic have crippled the polar bear population, and in 2008 they were officially listed as an endangered species.