Photo: Daniel J. Cox
Adaptations & Characteristics
How do polar bears survive, and thrive, on the Arctic sea ice? Follow Anuri to discover their secrets.
Wonderfully Adapted
In the Arctic, temperatures can plunge to -40° or -46 C (-50 F) in winter and stay that way for days or weeks. But polar bears are built for those conditions.
From fur to skin, to paws and claws, the sea bear’s physique is designed to protect them from the cold, hunt seals, and dominate the Arctic.
Photo: Daniel J. Cox
Two Layers of Fur
Polar bears have 2 layers of fur that prevent almost all heat loss. In fact, the fur keeps them so warm that adult males can quickly overheat when they run.
Surprisingly, their fur isn’t actually white. It just looks that way. Each hair shaft is pigment-free and transparent with a hollow core that scatters and reflects visible light.
Photo: Daniel J. Cox
Thick Padding of Fat
In addition to 2 layers of fur, a thick layer of fat helps keep the bears warm. A polar bear’s body fat can measure up to 11.4 cm (4.49 in).
In the water, polar bears rely more on their fat than their fur to keep out the cold; wet fur is a poor insulator. That’s why mother bears don’t like to swim with young cubs in the spring—the cubs don't have enough fat to stay warm.
Specialized Paws
Polar bear paws are ideal for getting around in the Arctic.
They’re huge—as big as dinner plates—and measure up to 30 cm (11.81 in) across. This helps the bears walk on thin ice without falling through.
The polar bear’s super-paws are also designed for swimming. The forepaws act like large paddles and their hind paws serve as rudders.
Slip-Proof Treads
Black footpads on the bottom of each paw are covered by small, soft bumps known as papillae.
Papillae grip the ice and keep the bear from slipping. Tufts of fur between their toes and footpads help with warmth, as well.
Powerful Claws
Thick, curved, sharp, and strong—each measures more than 5 cm (1.97 in) long. Polar bears use their claws to catch and hold slippery seal prey and to gain traction on ice.
Photo: Daniel J. Cox
Ears & Tails
Polar bear ears are small and round, and their tails short and compact, to prevent heat loss and conserve the most warmth possible.
Photo: Daniel J. Cox
Size & Weight
Adult males normally weigh 350- 600 kg (775-1,300 lb). Adult females are usually 150-290 kg (330-650 lb). But some can be larger. Researchers in Canada estimated one male bear at 800 kg (1,700 lb)!
Polar bears are also tall. Scientists usually measure their height at the shoulder when on all fours. Those heights are typically 1-1.5 m (3.3-5 ft) for adult polar bears. An adult male may reach over 3 m (10 ft) when standing on its hind legs.
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