Polar Bears International

© Daniel J. Cox/NaturalExposures.com

Diet

They are what they eat.

Polar bears depend on the high-fat content in seal fat. The bears prey on both ringed and bearded seals across their range, but will take other prey when available.

Blubber

When hunting is good and a polar bear's body is in good condition, the bear may eat only the seal's blubber and skin.

A polar bear can eat 100 pounds of blubber in a single sitting.

Ringed seals are the most accessible, especially to younger bears and females. Male polar bears also hunt larger bearded seals.

When an adult bear is in good shape, polar bears often eat only the blubber in order to build up the fat reserves they need to sustain themselves between meals. They leave the carcass for scavengers such as arctic foxes, ravens, and other bears.

A closer look at the polar bear’s main prey.

Ringed seals are the most abundant seal in the Arctic. They live in water and use land-fast, solid ice as well as ice floes for resting, molting, and giving birth.

Adult ringed seals have a thick layer of blubber and reach an average length and weight of 1 1/4 meters (4.1 feet) and 58 kilograms (150 pounds). Their backs are dark and spotted with cream-colored rings. Underneath, their coats are white to creamy yellow.

Seal pups are typically born in snow dens on land-fast ice in March and April. Their mothers nurse them for about two months and pups learn to swim and hunt as the ice breaks up in early summer. The seal pupping season is a time of plenty for polar bears, since naive young pups make easy prey.

Arctic warming also threatens ringed seals. Loss of ice limits their distribution, rain events can collapse lairs, and low snow years can mean seal pups are born in the open, where they become easy prey for arctic foxes, several bird species, and polar bears. In western Svalbard, changes in sea-ice extent and snow cover have led to reproductive failure for ringed seals in some areas.

© Daniel J. Cox/NaturalExposures.com

Alternative Food Sources

Terrestrial

While polar bears have evolved as a highly specialized predator of ice seals, they are always alert to other food sources—including vegetation, geese, bird eggs, and even the occasional small mammal.

Although individual bears may benefit from eating these alternative foods in places where they occur, there is no evidence they could provide enough calories, in the right form, to sustain polar bears at the population level.

Impact on the Ecosystem: Increased polar bear use of terrestrial foods would have negative impacts on land-dwelling species and others who rely on them for survival—the barren ground grizzly, arctic fox, wolves, several scavengers, and birds of prey.

Marine foods

Polar bears occasionally feed on other Arctic marine mammals, including bowhead whale remains, the walrus, and the narwhal.

Beluga whales or narwhals that become trapped in a small opening in pack ice can quickly become easy prey for bears.

While whale carcasses on the shore or those frozen in the sea ice offer a bonanza, none of these alternative marine foods are available on a predictable enough basis to offset the possible loss of ringed and bearded seals.

Bear Tracker

Watch polar bears as they travel across the sea ice to hunt seals.

Check out Bear Tracker

© Daniel J. Cox/NaturalExposures.com

Polar Bear FAQ

We answer the most frequently asked polar bear questions.

Go to FAQ

Climate Change

A threat to polar bears and the sea ice they depend on.

Learn More

© Daniel J. Cox/NaturalExposures.com