Polar bears are the poster animals of global warming. The image of a polar bear floating on an ice floe is one of the most dramatic visual statements in the fight against rising temperatures in the Arctic.
But global warming is not killing the polar bears of Canada's eastern Arctic, according to one ongoing study. Scheduled for release next year, it says the number of polar bears in the Davis Strait area of Canada's eastern Arctic – one of 19 polar bear populations worldwide – has grown to 2,100, up from 850 in the mid-1980s.
"There aren't just a few more bears. There are a ... lot more bears," biologist Mitchell Taylor told the Nunatsiaq News of Iqaluit in the Arctic territory of Nunavut. Earlier, in a long telephone conversation, Dr. Taylor explained his conviction that threats to polar bears from global warming are exaggerated and that their numbers are increasing. He has studied the animals for the Nunavut government for two decades.
Updates from the study by Taylor and his team have received significant media coverage in Canada, shaking the image of the polar bear as endangered.
"I don't think there is any question polar bears are threatened by global warming," responds Andrew Derocher of the World Conservation Union and a professor of biological sciences at the University of Alberta in Edmonton. He spoke by phone from Tuktoyaktuk in Canada's Northwest Territories 1,800 miles to the west of Davis Strait.
This past weekend, the midday temperature was just 6 degrees F. on the shore of the Arctic Ocean there. Daylight now lasts 18 hours, from 6 a.m. until just before midnight.
Perfect conditions for polar bear hunting. But Professor Derocher and a graduate student, Seth Cherry, are shooting the animals with tranquilizer darts and fitting them with radio transmitters. It's part of a long-term effort to figure out whether the huge carnivores – with the Kodiak bear, the largest on the planet – are being hurt by global warming.
The study by Taylor and his team has received widespread media coverage in Canada, shaking the image of the polar bear as endangered. There are even questions about the famous photograph of a polar bear adrift on what looks like an isolated and melting ice floe. Even scientists who firmly believe that the bears are under threat from climate change say the picture doesn't tell the whole truth.
Polar bears often travel on ice floes, and they can swim "easily" in open water for 60 miles, according to Derocher. "Bears will often hang out on glacier ice or large pieces of multiyear ice. To me that picture looked a little fudged," he says. "But some colleagues of mine said it was legit."
But Derocher still maintains the polar bear is threatened, even if its numbers aren't down all across the circumpolar region where the giant bears live and hunt (). Of the 13 polar bear populations in Canada, at least two are in decline, Derocher says. The number of polar bears along the western edge of Hudson Bay, for example, has fallen by 22 percent over the last decade.
"They are declining due to global warming and changes in when the ice freezes and melts in Hudson Bay," says Derocher. The port of Churchill on Hudson Bay has seen its shipping season lengthen because of disappearing ice.
Derocher and other scientists in his group are concerned that the retreating ice in the Arctic may pose a danger to future generations of polar bears because of habitat loss.
"The critical problem is, the sea ice is changing. We're looking ahead three generations, 30 to 50 years. To say that bear populations are growing in one area now is irrelevant," says Derocher.
That Davis Strait area where the bear population is thriving stretches from the southern part of Baffin Island, the fifth-largest island in the world, to the subarctic shores of Ungava Bay in Quebec Province and the coast of Northern Labrador. Just this one polar bear range covers an estimated 55,000 square miles, much of it open sea at certain times of year.
Animal rights activists can take some credit for the growth of polar bear numbers in the eastern Arctic. The battle to ban the hunting of harp seal pups has meant that the harp seal population has jumped from 2 million to 5 million. It also means sealers, especially those from Norway, are no longer hunting the polar bears, which they used to do when the seal hunt was larger.
"The increase in the population is not a climate-change related issue," Derocher claims. It's the result of "conservation and an increase in the harp seal population," he says.
Canada hosts two-thirds of the world's estimated 25,000 polar bears. Males can grow to be 11 feet long (5 feet tall at the shoulder) and weigh 1,500 pounds. The largest females are 7 feet long and weigh up to 700 pounds. Polar bears evolved from their cousin, the giant brown bears of Alaska, about 200,000 years ago.
Fully grown male polar bears are too big to wear the radio collars that Derocher and his team carry in their helicopter. Instead, they look for young males and females. Derocher says it's harder and harder to find polar bears in the area. Even native hunters say it's increasingly difficult to locate the animals.
Inuit hunters in the eastern Arctic, however, have long disagreed with scientists about polar bear numbers. In small Inuit communities, hunters kill bears that wander too close to human settlements.
The huge arctic territory of Nunavut is 730,000 square miles, bigger than Alaska and almost three times the size of Texas. It has a population of just 26,000, almost all of them Inuit.
Inuit hunters make their own estimates of the polar bear population based on the number of animals they encounter on their travels. Taylor says scientists have ignored the anecdotal evidence of the Inuit, who say bear numbers were rising. Inuits also report more polar bears wandering into their towns and villages, where they are a threat to children.
"I'm pretty sure the numbers [of polar bears] are climbing," says Pitselak Pudlat, an Inuit hunter and manager of the Aiviq Hunters and Trappers Organization at Cape Dorset, Baffin Island. "During the winter there were polar bears coming into town." His community is north of the bear population studied by Taylor.
Derocher worries about Taylor's evidence. Taylor and his team work for the Inuit-dominated government. For cultural reasons, that government wants to preserve hunting and keep polar bears off the endangered species list, Derocher says.
"It's not sport hunting I'm worried about. They're after big males, and there are enough of them for breeding," says Derocher. "But some populations of polar bears do need better protection."