Polar Bear Facts: The Sea Bear Whose Fur Isn't White at All
A polar bear crunching a fish in the snow looks exactly like the Arctic should: white on white, huge and calm. But almost nothing about this bear is what it first seems — starting with its colour. The polar bear is really a sea-going hunter in a clever optical disguise, built for a world made of ice.
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A Bear Named for the Sea
The polar bear's scientific name, Ursus maritimus, means sea bear, and it earns it: this is the largest land carnivore on Earth, yet it spends much of its life on frozen ocean. Big males can weigh 350 to 600 kilograms — as much as a small car. Polar bears are such strong swimmers, paddling with their front legs like a dog, that they have been seen many kilometres from any shore or ice.
Fur That Isn't White, Skin That Is Black
Here is the surprise: polar bear fur is not white. Each guard hair is actually translucent — see-through and hollow — and it only looks white because the hairs scatter light, the same trick that makes snow and clouds look white. Underneath all that fur, the bear's skin is jet black, which may help soak up warmth from the sun. A thick layer of fat under the skin, up to 10 centimetres deep, keeps the cold of the Arctic Ocean out.
Snowshoe Paws and Paddle Feet
A polar bear's front paws can measure 30 centimetres across — wider than dinner plates. On snow and thin ice they spread the bear's enormous weight like snowshoes, stopping it from crashing through. Between the toes, rough pads and tufts of fur grip slippery ice, and those same broad paws become powerful paddles in the water. Even the soles are mostly furred, like a pair of built-in winter boots.
Hunting Seals on a Melting Stage
Sea ice is the polar bear's hunting platform. A bear will wait motionless beside a seal's breathing hole for hours, relying on a sense of smell so sharp it can detect a seal nearly a kilometre away, or even under a metre of snow. When the ice melts in summer, the hunt pauses and the bears must fast on land. Because climate change is shrinking that ice season, polar bears are listed as vulnerable — their future depends on keeping their frozen stage.
Quick Summary
The polar bear (Ursus maritimus) is the world's largest land carnivore: a black-skinned, translucent-furred sea bear that hunts seals from the Arctic ice, and whose survival is tied to that ice lasting.
Frequently Asked Questions
Is a polar bear's fur really white?
No. The hairs are translucent and hollow, and they scatter light so the coat looks white — the same reason snow looks white. The skin underneath is actually black.
What do polar bears eat?
Mostly ringed and bearded seals, caught from the sea ice. They also scavenge carcasses and will try fish, birds, eggs and kelp, especially during the summer fast when the ice is gone.
How big is the biggest polar bear?
Large males stand over 3 metres tall on their hind legs and can weigh around 600 kilograms, making the polar bear the largest land carnivore alive today.
Why are polar bears vulnerable?
They depend on sea ice to hunt, travel and raise cubs, and the Arctic ice season is getting shorter as the climate warms. Less ice means less hunting time and longer, hungrier summers on land.