© Ondrej Prosicky / iStock
Polar bear diet
Polar bears are the top predator in the Arctic marine ecosystem. The polar bear’s body requires a diet based on large amounts of seal fat, making it the most carnivorous member of the bear family.
Food can be hard to come by for polar bears for much of the year. The bear puts on most of its yearly fat reserves between late April and mid-July to maintain its weight in the lean seasons.
The food-free season can last 3 to 4 months — or even longer in areas like Canada’s Hudson Bay. As the Arctic warms due to climate change, the ice pack is forming later in the season, and bears must wait longer to begin hunting again.
Did you know?
Don’t move! The polar bear often relies on “still hunting” — patiently waiting next to a hole in the ice until it senses a surfacing seal.
Hunting by smell. Using its sense of smell, the polar bear will locate seal birth lairs, and then break through the lair’s roof in order to catch its prey.
Learning to hunt. The adolescent polar bear often has to scavenge on the carcasses of other bears’ kills while learning to develop its own hunting skills.
Efficient digestion. The bear’s digestive system absorbs approximately 84% of the protein and 97% of the fat it consumes.
Fatty diet. The average polar bear can consume 2kg (4.4 lbs) of fat in a day.
A big appetite. The bear’s enormous stomach can hold 10-20% of its body weight.
What do polar bears eat?
Saimaa ringed seal (Pusa hispida saimensis). Saimaannorppa, norppa, Saimaa, jää, lumi, hylje
Ringed seal
Seals are a energy-rich food source, especially for hungry polar bear mothers and their growing cubs. Polar bears can devour huge amounts of fat from seals when they are available.
Bearded seal (Erignathus barbatus) lying on ice, Raudfjorden, Spitsbergen, Svalbard, Norway, June 2009
Bearded and other seals
Polar bears largely eat ringed and bearded seals, but depending upon their location, they may eat harp, hooded and ribbon seal. A 121-pound seal can provide 8 days worth of energy – but the bear needs to eat much more in order to store up reserves. When there are plenty of seals, adult polar bears only eat the fat, leaving the carcass for scavengers such as foxes, ravens and younger bears.
Polar bear (Ursus maritimus) eating seal carcass on ice, Spitsbergen, Svalbard, Norway.
Carcasses
Polar bears use their sense of smell to detect a carcass from nearly 20 miles away. They will happily feed on the carcasses of beluga whales, grey whales, walruses, narwhals and bowhead whales when available.
© naturepl.com / Sergey Gorshkov / WWF
Garbage, berries, seaweed and more
Polar bears may attempt to find alternate prey on shore, including muskox, reindeer, small rodents, waterfowl, shellfish, fish, eggs, kelp, berries and even human garbage. Bears attracted to communities by garbage or stored food may come into conflict with people.
Polar bear feeding on narwhal, Svalbard, Norway
Bigger prey
Occasionally, the bears will hunt narwhals, beluga whales and adult walrus.
