Sea ice, not open tundra, is the real habitat
Polar bears aren’t tundra animals that occasionally step onto ice. It’s the reverse: sea ice is home, and the coastline is just where a bear waits out the seasons when the ice retreats. Alaska’s records cluster along the Chukchi and Beaufort coasts, where pack ice forms close enough to shore for a bear to hunt from it for much of the year. When the ice pulls back in summer, bears either follow it north or come ashore and largely fast, living off fat reserves built earlier in the year. That rhythm drives the seasonal swing in reports. More bears show up near the coast in early summer, when retreating ice pushes them toward land, and reports thin out again once the pack reforms and bears move back out onto it, farther from where people are watching.
A body built for cold water
Under the fur, a polar bear’s skin is black, which helps it soak up what little solar heat the Arctic offers. The guard hairs on top look white but aren’t pigmented at all. They’re translucent and hollow, and they scatter light the same way snow does. A dense underfur and a thick layer of fat do the rest, letting a bear swim for hours in water that would kill an unprotected person in minutes. Its paws are broad and slightly webbed, working as paddles in the water and snowshoes on thin ice, with small bumps on the pads that grip slick surfaces. None of this is built for a life on grass and dirt. It’s a cold-water toolkit that happens to come with fur.
Hunting from the edge of the ice
A polar bear’s main prey is ringed seals, with bearded seals a heavier but less frequent meal. Most hunts happen at a seal’s breathing hole: a bear finds the hole by scent, then waits, sometimes for hours, for a seal to surface. Success is rare on any single try, so a hunting bear needs a lot of intact ice and a lot of patience. Bears also stalk seals hauled out on the ice, covering the last stretch in a slow crouch before a short, fast rush. Away from seals, they’re not picky. Bird eggs, carrion, and even a beached whale carcass all get eaten when the opportunity is there, though nothing replaces the fat a seal provides.
Cubs born in a snow den, mostly out of sight
Pregnant females dig a den into a snowdrift or frozen bank in early winter and stay there through the birth. Cubs are tiny and nearly hairless at birth. They nurse on extremely rich milk while their mother lives off her own stored fat, without eating or drinking herself. By the time the family leaves the den in spring, cubs weigh many times their birth size. They’re ready to follow their mother onto the ice. A female typically raises one to two cubs at a time and keeps them close for more than two years, teaching them to hunt before they head out on their own. That long dependency is part of why polar bear numbers can’t rebound quickly from a bad stretch.
A changing Arctic
The IUCN lists the polar bear as Vulnerable, and the reason isn’t hunting or habitat loss in the usual sense. It’s that the platform they hunt from is disappearing earlier each spring and forming later each fall. That shortens the window bears have to build the fat reserves they need. Bears spending more time on land, closer to coastal communities, is one visible symptom of that shift. It’s changing how people and bears share the same stretch of coastline in parts of northern Alaska. The record counts here don’t measure how many bears there are; they measure how many times and where people happened to see and report one. Read them as a map of contact, not a census.
Ringed and bearded seals make up most of a polar bear’s diet, and a successful hunt like this one can sustain a bear for days.
Cubs stay with their mother for more than two years, long enough to learn how to hunt seals from the ice before striking out alone.
