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Wildlife Branch


Polar Bears in Manitoba

  1. What do polar bears eat?
  2. How much do polar bears eat?
  3. How long do polar bears live?
  4. How many cubs does a female bear have?
  5. When are the cubs born?
  6. Where are cubs born?
  7. How long do the cubs remain with their mother?
  8. Where are polar bears found?
  9. Why are there so many polar bears in Churchill?
  10. What protects polar bears from the extreme cold?
  11. Why are polar bears white?
  12. Where are captured polar bears kept?
  13. How is climate change affecting polar bears?

Q: What do polar bears eat?

A: Because of the scarcity of plants in its icy habitat, the polar bear is the most carnivorous North American bear. With a keen sense of smell the polar bear can locate prey even when it is hidden by snowdrifts or ice.

Seals are the polar bear's primary prey, particularly the ringed seal and, sometimes, the bearded seal. When hunting is good, polar bears will typically eat only the fat and leave the rest of the carcass for scavengers including arctic foxes, ravens, and younger bears.

While seals are its main food source, the bears have been known to kill and eat both walrus and beluga whales, hunt short-legged reindeer and sometimes snack on other foods including birds, bird eggs, kelp, and beached whales.

Q: How much do polar bears eat?

A: Polar bears have developed very large stomachs capacities, which allows them to take advantage of unexpected meals. Their ability to store body fat enables them to go long periods without any food.

Q: How long do polar bears live?

A: In the wild, polar bears live an average of 15 to 18 years, although biologists have tagged a few bears in their early 30s. In captivity, they may live until their mid- to late 30s. One zoo bear in London lived to be 41.

Q: How many cubs does a female bear have?

A: There are usually two cubs in a litter. Female polar bears have their first set of cubs between the ages of four and eight (most frequently at age five or six). Polar bears have one of the slowest reproductive rates of any mammal, with females typically producing five litters in their lifetime.

Q: When are the cubs born?

A: Polar bear cubs are born around November to January in snow dens called maternity dens.

Q: Where are the cubs born?

A: The peatlands south of Churchill also provide ideal habitat for pregnant females to dig maternity dens. This is one of the only places in the world where maternity dens are dug into the ground. The female bears seek out the soft peatlands for their dens. Some dens are over 100 years old. In most other places, maternity dens are dug into snowdrifts along mountain slopes or hills near the sea ice.

Q: How long do the cubs remain with their mother?

A: Polar bear cubs normally stay with their mother until they are 2 1/2 years old, although some bears in the Hudson Bay area wean their young at age 1 1/2. During the time that the cubs are with their mother, they must learn how to hunt and survive in one of the Earth's harshest environments.

Q: Where are polar bears found?

A: Polar bears are found near the North Pole, northern Canada, Alaska and Arctic Islands. The bears may also inhabit broken ice packs at the northern edge of the North American continent. Churchill is a prime area for seeing these beautiful and powerful creatures. The lowlands of Hudson Bay and James Bay, are one of the world's largest denning areas for Polar Bears.

Q: Why are there so many polar bears in Churchill?

A: In spring as the ice begins to break-up, the strong winds on the Hudson Bay create a counter clockwise current which naturally forces the bears onto the shores of Manitoba south of Churchill. In the summer months there are few bears around Churchill.

In late autumn, ice begins to form north of Churchill along the western shore of Hudson Bay. Many polar bears move north along the shore and pass through the town on their way to intercept the ice as it forms. By moving north to intercept the ice, the bears shorten the time they spend fasting on land. Once on the ice they can begin to hunt seals again.

Polar bears have been migrating this route for thousands of years, long before the town of Churchill was built.

Q: What protects polar bears from the extreme cold?

A: Polar bears are covered with a heavy fur. The coat consists of two layers - a dense undercoat of fine white hair and outer coat composed of glossy guard hairs. The individual guard hairs are hollow which helps to make the polar bear more buoyant when swimming. The guard hairs also shed water easily, so that after a swim the polar bear can shake itself like a dog to decrease chilling and to dry itself fairly quickly.

The thick layer of fat beneath their skin protects them against the cold. The actual colour of the skin of the polar bear is black.

Q: Why are polar bears white?

A: The colour varies from pure white to more of a yellow hue. The white fur is important camouflage for the bears as they hunt their prey out on the ice pack.

Polar bears are clever in their use of cover, be it land, water, or ice. This aids both their hunting of seals and their own escape from human hunters. The soles of the bears' feet have small bumps (called papillae) and cavities that act like suction cups which help to keep them from slipping on the ice.

Q: Where are captured polar bears kept?

A: In 1980 a polar bear holding facility, called D20, was constructed in Churchill. Natural Resource officers only capture bears when the are deemed a threat to people. The polar bears are held in D20 and are not fed. The bears are naturally fasting during the summer months.

The holding facility has a capacity for 23 polar bears. The bears are held until the ice freezes and then released. If there are too many bears in the holding facility, a few bears are tranquillized and flown a short distance Northwest rather than waiting for the Hudson Bay to freeze.

Q: How is climate change affecting polar bears?

A: The major threat to the western Hudson Bay population of polar bears is global warming. The increase in temperature leads to changes in the sea ice, which is the preferred habitat of polar bears. It is on the ice that bears are able to kill seals. Changes in the ice which affect the seal population or the bear's ability to kill seals would adversely affect the bear population.

When the ice melts, they move ashore and survive on stored fat until the following winter when they can hunt seals on the ice once again. Most bears fast for about four months, however pregnant females remain on land to give birth and fast for about eight months. Early ice break-up cuts short their time to hunt and build up their body condition, and longer ice-free periods extend the time that the bears fast on shore. Studies have shown that for each week early that break up occurs, the bears come ashore ten kilograms lighter and thus in poorer condition.

Warmer weather for Hudson Bay can have other catastrophic impacts on polar bears. Spring rains can collapse maternity dens before mother and cub have departed and can impact the maternity dens of ringed seals, the primary prey species for our polar bears. If the ringed seal population declines as a result, the polar bear population would decline in turn.