Inupiat Eskimo guide Sam Leavitt leads a search for polar bears
Three hundred miles (480km) north of the Arctic Circle, Sam Leavitt drives his big truck along a snow-covered beach on the coast of Alaska, next to the Beaufort Sea.
It is nearly 10 degrees below zero. The waves freeze into shards of ice as they hit the shore, but the truck's window is down and Sam's huge hands are bare. He wears only a cotton hooded top and jeans.
Sam, an Inupiat Eskimo, was born and raised in Barrow, Alaska's most northern town. He recounts the changes local people have seen in the polar bear population.
"Six polar bears recently drowned out in the open water. Their bodies were spotted by sailors."
The cause, according to Sam, would have been exhaustion.
"He's trying to swim, he can swim over 100 miles, but it's like 200 miles out, and that's too far, even for a polar bear."
In autumn, female polar bears head from the ice to the land, to build dens in snowdrifts and give birth.
I never cease to be amazed at the amount of value people hold to fish and wildlife
Sam believes the ice is too distant from the land for some bears to make it to shore.
In May 2008, the polar bear was categorised as threatened under America's Endangered Species Act (ESA). Research and climate modelling by US federal scientists predicted a near-catastrophic reduction in the polar bear population as the sea ice retreats.
Rosa Meehan, at the US Fish and Wildlife Service in Anchorage, Alaska, believes the polar bear population is on the brink of collapse.
"What we found and what we've been able to model is a really dramatic loss of sea ice...[We] now have pretty solid projections of dramatic declines in polar bear populations.
"Prior to the listing it was a general sense of 'oooh this is bad, this is likely to happen'. With the listing we did a very detailed analysis and now have a very clear picture of where we see the world going," Ms Meehan says.
The listing obliges the authorities to come up with a conservation plan, and to protect the polar bears' habitat.
Now John McCain's running mate in the US election has picked a fight with Washington over the polar bears. In her capacity as governor of Alaska, Sarah Palin has mounted a legal challenge against the decision to put polar bears on the ESA list.
The Governor's website gives these reasons:
the decision was not based on best science and commercial data
the polar bear population has doubled in the past 40 years to almost 25,000 worldwide
it could deter fishing, oil and gas exploration, transport and tourism.
The Alaska Department of Fish and Game, where state hunting permits are sold, is putting forward Governor Palin's side of the argument.
For a civil service building, its lobby is unusual - big game trophies such as caribou, bears and the world's biggest moose ever to be "taken" adorn its walls. Alaskans do not shoot bears, they "take" them.
The department's endangered species co-ordinator, Doug Vincent-Lang, enthuses about Alaskans' attitude to animals.
Can man and bear both continue to thrive in Alaska?
"I never cease to be amazed at the amount of value people hold to fish and wildlife", he says.
But Mr Vincent-Lang argues the evidence used to put polar bears on the ESA list just was not strong enough.
"I guess it's our feeling that the ESA has strict legal standards as to whether a species should be listed as either threatened or as endangered.
"We do not feel based on looking at the best available science that those thresholds have been reached in the case of polar bears," he said.
His department believes in developing other conservation stategies, including additional research and monitoring, to ensure polar bears remain viable, he says.
There are plenty of Alaskans who agree with Governor Palin's decision to try to overturn the threatened species listing.
In the gun section of the Sportsman's Warehouse, in downtown Anchorage, salesman Tom Mobley gently takes down his favourite hunting rifle from the hundreds on display racks behind him. It costs nearly $4,000 and is made of woven carbon fibre.
Hunting has long been a way of life in the state
Tom works the mechanism and explains that it is a bolt action rifle.
"It uses the model 700 Remington titanium action, probably the best action in the world."
Tom says he respects every animal he shoots.
"Upon taking game I actually do thank it, even though it is dead. I say a little prayer. To me it's respect to the game. Some people think I'm crazy, but I can live with that."
He says Alaskan hunters have great respect for wildlife, but his attitude to listing polar bears is uncompromising.
"That bear is no more endangered than I am. This is hype so these organisations can get their way and get money."
"They're more dangerous to humans than any animal out there. Global warming? It's natural in my book. Yes man may contribute a little wee bit, but nothing Mother Nature can't handle. Excuse me people, you're wrong, you're wrong, you're wrong".
Others interpret Mrs Palin's actions in a different light.
Rick Steiner, marine scientist at the University of Alaska, says the governor's objection to the listing has little to do with science.
"The reason they were worried about this listing is because of the potential legal threat to oil and gas development in the Arctic both onshore and offshore. They made a political decision and misrepresented the basis of their decision to the public."
Sam Leavitt in the company of one of the last bears to be hunted legally
After Mrs Palin's vice presidential speech in which she uttered the phrase "drill baby drill", there's little doubt that securing future energy supplies is high on her list of priorities.
And there is a lot of potential in her own back yard. An estimated 20% of the world's untapped oil and gas reserves lie under the Arctic ocean.
When we put to it to Mr Vincent-Lang that the state government's position was motivated by oil, gas and business, rather than research, he pointed to Alaska's record.
"Those industries are all important to the state of Alaska, you're correct. But at the same time we're confident in our ability to regulate development activities and still preserve fish and wildlife uses.
"For instance, we've had significant oil and gas development in the North Slope over the last 30 to 40 years, a period of time where you might note that polar bears have also increased substantially in numbers."
Sam gets out his jeep, binoculars in hand, trying one last time to see if he can see a polar bear.
"Only seagulls, polar bear's Sunday today, holiday," he chuckles.
He hopes that the bears will exist for the next 2,000 - he wants his great grand-children to know the great arctic bear.
It will take a couple of decades before we know who is right about the polar bear, and whether it can surmount the challenges of climate change, but it might be too late by then. Some scientists believe the polar bears in Alaska could become extinct in 50 years' time.
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