Diet & Prey

In fall, a seal cuts 10 to 15 breathing holes (known as aglus by Canadian Inuit) in the ice, using the sharp claws on its fore flippers.

Seals keep their breathing holes open all winter long, even in ice up to 2 m (6 ft) thick. They surface about every 5 to 15 minutes at one of the holes or use air pockets trapped under the ice when available.

Polar bears attack by waiting for seals to breathe at the openings. They locate them with their powerful sense of smell and wait for the seals to emerge. Polar bears have to be smart and patient because the wait can be long—sometimes hours, or even days.

Bears also stalk ringed seals that are basking on ice by taking advantage of their sleep-wake rhythms.

The bear crawls slowly forward and freezes in place when the animal raises its head. At about 6 m (20 ft) from the seal, the bear uses its explosive speed to pounce, killing the seal before it can escape back into the sea.

Polar bears have evolved to prey on seals. But they are curious and will eat other foods when available — including geese, bird eggs, whales that wash up on the beach, and even the occasional small mammal.

All of these foods are less predictable, however. And most of them, except whales or walruses, don’t provide enough calories to sustain the polar bear’s massive body size or build up the bear’s fat reserves. 

While individual bears may benefit from eating these foods, they would not provide enough calories, in the right form, to sustain polar bears at the population level.