How Do Polar Bears Survive in the Arctic? Facts, Adaptations, and Life on the Sea Ice

Polar Bears of the Tundra

By William Drumm, underwater photographer and ocean ambassador

I photographed these polar bears from a Tundra Buggy in Churchill, Manitoba, and what I saw made me want to learn everything.

There was a moment, sitting in a Tundra Buggy on the tundra outside Churchill, Manitoba, when a polar bear stood up and leaned on the side of our buggy; and my heart stopped. Until you see, hear, and smell polar bears up close, it’s hard to grasp their size and their disposition. 

The polar bear that leaned on our buggy was around 11 ft tall from toes to nose. The sound of him breathing was as loud as a man’s voice, and you could almost hear it picking apart and processing the various scents as he inhaled. The bear gave off a stagnant odor of something long dead, as he was only recently feeding on mummified bird carcass (the only food around) before coming over to try his luck with our Tundra Buggy.

These massive animals move with a kind of confidence that only makes sense once you understand where they live, and what they’re built for.

I traveled to Churchill in autumn, just before the return of the sea ice, to photograph polar bears. We stayed at the Tundra Buggy Lodge, a cluster of large all-terrain vehicles linked together like a train, with separate buggies for sleeping, dining, and a lounge. We photographed from the buggies themselves, which elevate you just above the bears and let you get incredibly close without disturbing them or risking a polar bear attack.

What struck me immediately was how hungry they were. We arrived right before the sea ice returns to Hudson Bay, which means the bears had been on land for months, fasting, conserving energy, waiting. A polar bear’s entire year revolves around that moment the ice comes back and they can hunt again.

After spending days with these animals, I came home wanting to understand them better. So I did the research. Here’s what I learned.

What Makes Polar Bears Different from Other Bears?

Polar bears (Ursus maritimus – Latin for “sea bear”) are classified as marine mammals, which puts them in the same category as seals, walruses, and whales. That’s not a trivial distinction. They depend on the ocean ecosystem for survival in a way no other bear species does.

Unlike grizzly or black bears, polar bears are almost exclusively carnivorous. They don’t forage for berries or dig for roots. They eat seals, and specifically the calorie-dense blubber that seals carry. Seeing a bear eat a dried up bird carcass showed how hungry the bear was. 

There are approximately 26,000 polar bears in the world today, spread across the Arctic regions of Canada, Greenland, Russia, Alaska (United States), and Norway (Svalbard). Canada is home to roughly two-thirds of the global population, which is part of what makes Churchill, sitting on the western shore of Hudson Bay, one of the best places on earth to see them.

How Are Polar Bears Adapted to Cold Weather?

The adaptations that let polar bears thrive in -50°C temperatures are layered, literally and figuratively.

Fur that is not white at all. This might be the fact that surprises people most. Polar bear fur is transparent, each hollow hair shaft scatters and reflects visible light, which is why the coat appears white or yellowish. Underneath all that fur is jet-black skin, designed to absorb solar heat. Two layers of fur trap air close to the body, providing insulation so effective that adult males can overheat just from running.

Four inches of fat. Below the skin sits a thick layer of blubber, sometimes over four inches deep. This insulates the body during swims in near-freezing water and during the long fasting periods on land.

Paws built for two environments. A polar bear’s paws can measure nearly a foot across. The wide surface distributes their weight on thin ice. The footpads are covered in small soft bumps called papillae that grip the ice like traction studs. And the slightly webbed toes make those same paws effective paddles in the water. Fur even grows on the bottom of their feet for insulation.

A streamlined body for swimming. Compared to other bears, polar bears have a longer neck, narrower skull, and more elongated body, features that reduce drag in the water. Their scientific name says it all.

Do Polar Bears Live in Alaska? What About Antarctica?

Polar bears live across the circumpolar Arctic, but their real home isn’t land, it’s sea ice. The ice is their hunting platform, their highway, and in some cases their den.

They’re found in five countries: Canada, the United States (Yes, polar bears live in Alaska), Russia, Greenland, and Norway. Polar bears are only found in the Arctic, and do not live in Antarctica. Within those borders, they’re drawn to coastlines, islands, and the shifting edges of sea ice where seals surface to breathe.

Why Does Sea Ice Matter So Much?

Polar bears are not fast enough to catch seals in open water. They depend on ice as a platform, waiting motionless at breathing holes or at the ice’s edge for a seal to appear, then striking with surprising speed. Without ice, that hunting strategy falls apart entirely.

The bears I photographed in Churchill illustrated this perfectly. Hudson Bay freezes over in winter, which brings the bears back to hunt. But in autumn, when the ice is still weeks away, they’re stranded on land with no food source. The bears we saw were lean and quiet, conserving every calorie while they waited. Some had been fasting for five months or more. It was hard to see how hungry they were.

How Fast Can Polar Bears Run and How Far Can They Swim?

For an animal that can weigh over 1,500 pounds, polar bears move with remarkable efficiency.

On land, they can run in short bursts up to 25 miles per hour, though they rarely do as burning calories is something polar bears avoid whenever possible in an environment where food is scarce and unpredictable.

In water, they swim using powerful front paws as paddles, holding their hind legs flat like a rudder. They’re strong, sustained swimmers. Some individuals have been recorded swimming more than 60 miles without stopping, which has become increasingly necessary as sea ice retreats and the distances between ice floes grow wider.

They are solitary animals that roam enormous territories, home ranges can exceed 600,000 square kilometers in a single year. And they navigate these territories largely by smell. A polar bear’s sense of smell is extraordinary: they can detect seals nearly a mile away, and can smell seal dens hidden under several feet of snow.

How Do Polar Bears Hunt?

Polar bears are patient, methodical hunters, nothing like the dramatic predator chases you might picture. Most hunts involve long periods of waiting.

Their main technique is called still hunting: they locate a seal’s breathing hole in the ice (by smell), then stand or crouch nearby, motionless, sometimes for hours. When the seal surfaces, the bear strikes with its forepaws and hauls the animal onto the ice. It feeds primarily on the blubber, often leaving the muscle behind.

Despite spending roughly half their lives hunting, polar bears have a relatively low success rate, some studies suggest that less than 2% of hunts succeed. That’s why access to blubber-rich seals during the winter and spring sea ice season is so critical. A successful polar bear can consume 100 pounds of blubber in a single sitting, packing on the fat reserves it needs to survive the lean months on land.

What do polar bears eat? Their primary prey is ringed seals and bearded seals. They’ll also eat walruses, beluga whales, bird eggs, carrion, and occasionally vegetation, but none of these come close to replacing seals nutritionally. Polar bears are the most carnivorous of all bear species.

How Do Polar Bears Reproduce? Cubs, Dens, and Development

Only one type of polar bear dens in winter: pregnant females. Males and non-pregnant females remain active year-round.

As autumn arrives, a pregnant female digs a maternity den into a deep snowdrift, often on land near the coast. The den insulates against the cold and provides a protected space for birth. She then waits for snow to seal the entrance and give birth inside, in November or December.

Polar bear cubs are born tiny, weighing less than half a kilogram, roughly the size of a guinea pig. They are blind, nearly hairless, and completely dependent on their mother. They grow rapidly on milk that contains about 31% fat, one of the richest milks produced by any land animal.

By spring, the family emerges onto the sea ice for the first time. Cubs typically stay with their mothers for two to two-and-a-half years, learning how to hunt, navigate the ice, and survive. The mother can go up to eight months without eating during this period, one of the most extraordinary feats of endurance in the animal kingdom.

Females typically have their first litter around age five and reproduce slowly, a new litter roughly every three years. This slow reproductive rate becomes critically important when we talk about conservation.

Are Polar Bears Endangered? Conservation Status Explained

Polar bears are currently listed as ‘Vulnerable’ on the IUCN Red List. Not yet Endangered, but facing serious, accelerating threats.

The primary threat is climate change. The Arctic is warming roughly four times faster than the rest of the planet. Sea ice is forming later in the year and melting earlier, which shortens the window polar bears have to hunt and build the fat reserves they need to survive and reproduce. Longer ice-free seasons mean longer fasting periods on land, exactly the situation the Churchill bears are living through every autumn.

The consequences are measurable: lower body weights, fewer surviving cubs, and increased mortality, particularly for older bears and first-year cubs. Similar warning signs are showing up across other apex predators. See how shark populations are responding to conservation efforts.

Other threats include:
– Oil and gas exploration in Arctic waters (contact with oil spills damages insulation)
– Increased Arctic shipping traffic
– Toxic chemical accumulation through their prey
– Human-wildlife conflict as bears spend more time near communities on land

A 2020 study projected that without significant action on greenhouse gas emissions, all but a few polar bear populations could collapse by the end of the century. Because polar bears reproduce slowly, population recovery takes decades. When numbers fall, they don’t bounce back quickly.

Frequently Asked Questions About Polar Bears

Why is polar bear fur transparent, not white?

Each hair shaft is hollow and pigment-free. It scatters visible light, making the coat appear white or yellow, but the fur itself is colorless. This also provides insulation, trapping air close to the black skin beneath.

Are polar bears considered marine mammals?

Yes. Because they depend so heavily on sea ice and marine ecosystems for food and habitat, polar bears are classified as marine mammals alongside seals, walruses, and cetaceans.

How many polar bears are left in the world?

Scientists estimate the current global population at approximately 26,000 individuals, spread across 19 subpopulations. Population trends vary by region, with some subpopulations declining.

Do polar bears live in Antarctica?

No. Polar bears live only in the Arctic. Antarctica is home to penguins, and no bears of any kind.

Are polar bears and grizzly bears related?

Closely. Polar bears evolved from brown bears relatively recently, genetic evidence suggests the split occurred between 150,000 and 500,000 years ago. The two species can still interbreed, producing what’s known as a “pizzly” or “grolar” bear. These hybrids have been documented in the wild and are becoming more common as warming drives grizzlies into Arctic habitats.

What should I know if I want to photograph polar bears in Churchill?

Churchill, Manitoba is considered the polar bear capital of the world. The best time to visit is October and November, just before Hudson Bay freezes over and the bears head back to the ice. Tundra Buggies are large all-terrain vehicles designed specifically for wildlife viewing on the tundra, they allow close encounters without disturbing the animals. The Tundra Buggy Lodge offers the unique experience of staying overnight on the tundra itself, giving you maximum time with the bears in their environment.

More Than Just an Arctic Symbol

Polar bears are often reduced to a symbol of the Arctic, of climate change, of wilderness. But spending time with them in Churchill changed that.

They’re patient, intelligent hunters navigating a world that is shrinking around them. Every adaptation, the transparent fur, the black skin, the dinner-plate paws, reflects millions of years of refinement for a specific, extraordinary environment. And every year that environment becomes a little less stable.

Understanding polar bears means understanding their relationship with sea ice: what the ice provides, what losing it costs, and how much depends on what happens next.

The bears I watched from that Tundra Buggy were waiting for the ice to come back. They’ve been doing it for hundreds of thousands of years. The question is whether it will keep coming.

I used several sources for this blog. To learn more about polar bears, I recommend checking out World Wildlife Fund, National Wildlife Federation and Polar Bears International.

Thank you Frontiers North for the incredible Tundra Buggy expedition.