Ausgabe 52/2005

Climate Change The Polar Bears' Last Stand

Global warming is causing famine-like conditions for polar bears in the Canadian province of Manitoba. The feeding season is shorter and the ice is thinner -- bears are slowly starving, weak bears are drowning and they are leaving behind orphans. Scientists in Canada are trying to save the species by finding foster families for orphaned cubs.

By Annika Thomé

Anyone who lives in Churchill in the North Canadian province of Manitoba knows the polar bear hotline number by heart. Local residents have good reason to: every year, between October and January, this 1,000-strong community is a favorite stomping ground of polar bears. Indeed, the number of bears passing through the city in a year often outnumbers the population of humans, making this the "Polar Bear Capital of the World."

Global warming literally has polar bears walking on thin ice and in danger of extinction.

Global warming literally has polar bears walking on thin ice and in danger of extinction.

Around this time hundreds of the large land-living carnivores roam the area. After a meager summer spent in the tundra, the bears are now waiting, with rumbling stomachs, for the Hudson Bay to freeze over, so that they can go back to hunting seals on the massive ice floes.

Recently, the residents of Churchill have been forced to call the polar bear emergency number more often than ever. The effects of climate change on the bears' natural habitat is causing the furry white giants to become more aggressive.

The period in which the ice is stable enough to support fully grown bears is getting ever shorter. Each year, the winter arrives later and later, and in spring the ice starts to melt earlier. The result is that the bears don't get the chance to eat enough to build up the layer of fat necessary to keep them warm. On average, today's polar bears weigh 80 to 90 kilograms less than they did 15 years ago. Only rarely do the largest male bears reach their maximum natural weight of 1 ton.

Often animals weak from hunger end up drowning because they have dared to venture out too early onto dangerously thin ice. The young left behind don't stand a chance of surviving in the wild alone.

Finding surrogate mothers for orphaned cubs

Kim Daley, a 34-year-old Canadian biologist who works for the Born Free Foundation, looks after these orphaned cubs. "We give young animals who have been left to fend for themselves a second chance in the wild," she says, as she tramps through the snow in her green down-jacket and lined rubber boots.

But Daley is only now starting to realize just how difficult it is to find surrogate parents for the young animals. She recently managed for the first time to follow the fate of an adopted cub using transmitters that give the animal's location. It turned out to be a frustrating experience.

The biologist spotted the perfect surrogate mother for her nine-month-old charge by plane: a female polar bear, which was well-fed and had a cub of a similar age. The bear was traveling east of the Nelson River, a good 300 kilometers away from Churchill. Daley notified her colleagues by radio, who immediately anaesthetized the foundling and loaded it into a helicopter.

Before uniting the foundling with its new family, Daley tranquilized the surrogate mother bear. "We marked her back orange and checked whether she had enough milk," the biologist explains. A collar, with an inbuilt radio transmitter which would give the animal's whereabouts, was also attached to the bear's neck.

The crew carefully placed the orphaned cub between the sleeping bear and her own offspring. The problem remained that female bears don't accept cubs with a foreign smell. To trick the bear's sensitive sense of smell, Daley used Vicks VapoRub. She spread the medication generously over the snout, head and rear of the bears to mask the foreign cub's scent.

From the air, the biologist saw the older bear lift her head, sniff the cubs and gently nudge them awake. With fuel running low, the team was then forced to head home.

A few weeks later the pilots of the Hudson Bay Helicopters fleet reported seeing the three bears still harmoniously together. But then, on further observation flights, the pilots noticed that suddenly only two were left. "There was no trace of our foundling. Chances are slim that it has found another mother or has survived alone," Daley says. The small bear has probably starved to death.

Female polar bears generally give birth to one or two cubs. They are as small as rats, weighing about 600 grams. Thanks to the mother's nutritious milk, they quickly put on weight. Normally the mother polar bear leaves her young to fend for themselves when they are about two-and-a-half years old.

Polar bears live under year round protected status in Canada. Indigenous people are only allowed to shoot the animals for their own needs. But it's not food people are looking for when they hunt the large animals -- polar bear meat often contains parasites, such as threadworms, which nest in the small intestine and muscles and can be deadly for humans. That, however, doesn't deter criminals, who want to get their hands on the bear's fur, a highly sought-after trophy. Each year, some 700 polar bears in Canada fall victim to poachers. Experts estimate that there are a mere 15,000 polar bears left in Canada out of a total estimated world population of barely 22,000.

Bad news for tourism

The shrinking population has hit Churchill particularly hard and is something which has worried local residents for a long time now -- Churchill's survival depends on bear tourism.

Every winter hundreds of adventurers and photographers make the pilgrimage to the frozen peacefulness of Canada's wilderness. Well-heeled tourists spend their entire Christmas vacation in barracks and containers, freeze their toes blue in temperatures of minus 40 degrees Celsius and bounce along former military trails in uncomfortable, frozen snow-buggies -- all in order to, for once in their lives, see a polar bear in the wild.

But the four-legged animals can also be viewed in captivity. Near the airport up to 22 polar bears sit behind bars -- in their search for food these animals had come a little too close to the residents of Churchill for comfort.

The gamekeepers on call certainly have quite a job on their hands. The animals are inoculated, weighed and tattooed. Only then are they allowed to be released. The large white animals are then finally transported back on to the ice by helicopters, far enough north of Churchill so that they no longer pose a threat.


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