Adaptation of young polar bears – key to survival?

Mother Nature is truly resourceful at providing new survival foods. The snow goose and elder duck eggs could help polar bears survive. The egg supply in part is coming from a rebounding over population of snow geese in the Hudson Bay area. ‘Canada’s vulnerable polar bear population could survive the effects of climate change by switching a significant part of their diet from seal meat to scrambled eggs, according to a new U.S. study that suggests snow geese nests along the Hudson Bay shore may become a key feeding site for the iconic Arctic mammal.snow20goose20on20nest
The study, headed by American Museum of Natural History biologist Robert Rockwell, says warming temperatures and changing ice conditions in one of Canada’s prime polar bear habitats Cape Churchill Peninsula in northern Manitoba have created a longer stretch of time each spring when young bears are searching for food in the same coastal area where snow geese are nesting.

Polar bears have been losing their ice platforms used to hunt for seals forcing some bears particularly young males to forage for food farther north or onto land. Trouble is they are not good land hunters in the past if they were stuck on land for months, a polar bear would typically survive on its own fat reserves not prey

Over 40 years “young male bears were seen among snow goose nests…” says Robert Rockwell, an ornithologist at the American Museum of Natural History and a biology professor at City University of New York’s City College. “I’ve seen  a young male eat eider duck eggs whole or press its nose against the shell, break it, and eat the contents.”060913191415

The warming temperatures and changing ice conditions in one of Canada’s prime polar bear habitats Cape Churchill Peninsula in northern Manitoba  have created a longer stretch of time each spring when starving young bears are searching for food in the same coastal area where snow geese are nesting. They are coming ashore earlier. The eggs may be deficient in calories  as well as other nutrients. We will have to watch as evolution is taking place in front of our eyes. Hungry juveniles “are beginning to overlap the nesting period of the large colony of snow geese” occupying the tundra north of Churchill. “”Polar bears are known to eat snow goose eggs, and since obtaining such a resource would not involve the high costs of a chase across the tundra, the eggs could compensate for some of the energy deficit associated with lost seal-hunting opportunities,” the study stated. “The obvious questions are whether polar bears and nesting geese will increasingly overlap and how much energy is available for the bears.”
In one case described in the paper, a scientist observed a polar bear gobble “the contents of about 10 nests and then rest for up to an hour before resuming foraging.”

The authors themselves witnessed a young bear as it consumed eggs from about 200 eider duck nests near Manitoba’s La Perouse Bay.
eider-ducks-eggs-102
Above image elder duck eggs.

How much energy is available for the polar bear from eggs?

We do not know, but it is a step in a new direction towards survival we hope.

Area these bears are now seen foraging.manitoba-map1

Resources

Eggs key to polar bear surviva: Study – Randy Boswell   Canwest News Service December 15, 2008
Polar Bears Find New Food Source – LIVE SCIENCE STAFF   LiveScience
ANIMAL NEWS, SCIENCE NEWS
Dec. 15 , 2008.

Images courtesy of

snow goose and eggs image (google images)  www.aknextgeneration.org

polar bear image  U.S. Fish and Wildlife Service – Dave Olsen

elder duck image (google images)   http://www.arcticvoice.org

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