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Wildlife in Manitoba File# 3820730

Polar bears

In the last two decades, polar bears living in the western Hudson's Bay area have undergone a change for the worse. Bears are returning from the sea ice underfed and underweight. In poor condition, mother bears are less likely to successfully raise offspring. The plight of Manitoba's great white bears is inexorably linked to climate change.

The polar bear is the most carnivorous of the bears, feeding primarily on ringed seals and occasionally on bearded seals. Polar bears are at their leanest in March, just before the seal pupping season. Bears rely heavily on the predictable spring abundance of ringed seal pups to provide energy and nourishment for survival throughout the year - particularly for raising and nursing cubs (1).

At six weeks of age, the body weight of ringed seal pups is about 50% fat (2).

Seal pups are abundant from their birth in April to the breakup of the sea ice in early summer. The pups are easier for polar bears to catch because they are inexperienced. As a result, the bears are usually able to refill much of their dwindling energy stores every spring, stalking seals on the sea ice.

Polar bears need stable sea ice as a solid surface on which to hunt ringed seals. Anything that affects the distribution and annual duration of sea ice has a profound effect on the health and well-being of polar bear populations (3). Since 1981, ice breakup on Hudson Bay has occurred earlier and earlier, forcing bears to come ashore in progressively poorer condition (4). Their hunting season cut short, they do not have enough time to regain their energy stores.

Increased temperatures caused by human-made greenhouse gas emissions are responsible for melting the arctic ice out from under the bears' feet.

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Ringed seals

Ringed seals are an important food source for Polar Bears. They also depend on stable, landfast sea ice and adequate snow cover to rear pups (5).

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Beluga whales

Beluga whales are found in Hudson's Bay, and almost always close to sea ice. They prefer to forage at ice edges and cracks (6).

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In Canada, general warming is allowing red foxes to expand their range northward (7). Unfortunately for arctic foxes, redfoxes are better suited to living in a warmer environment.Arctic foxes are retreating further north as their habitat shrinks.

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Image of "howling wolf" by Terry Spivey, USDA Forest Service, Image # 1374864,

Wolves, moose, and trees

With increased winter snowfall in the North Atlantic region of North America, wolves are hunting in larger packs (8).

Triple the numbers of moose are killed per day, compared to less snowy years when wolves hunt in smaller packs (9).

With fewer moose feeding on their lower branches, fir trees quickly fill in the forest's understory.