Frequently Asked Questions
- What do polar bears eat?
- How much do polar bears eat?
- How long do polar bears live?
- How many cubs does a female bear have?
- When are the cubs born?
- Where are cubs born?
- How long do the cubs remain with their mother?
- Where are polar bears found?
- Why are there so many polar bears in Churchill?
- What protects polar bears from the extreme cold?
- Why are polar bears white?
- Where are captured polar bears kept?
- 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.
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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.
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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.
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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.
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Q: When are the cubs born?
A: Polar bear cubs are born around November to January in snow
dens called maternity dens.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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