KAKTOVIK (Alaska) • Come autumn, polar bears are everywhere around this Arctic village, dozing on sand spits, roughhousing in the shallows, padding down the beach with cubs in tow and attracting hundreds of tourists who travel long distances to see them.
At night, the bears steal into town, making it dangerous to walk outside without a firearm or bear spray.
On the surface, these bears may not seem like members of a species facing possible extinction.
Scientists have counted up to 80 at a time in or near Kaktovik; many look healthy and plump, especially in early autumn, when their presence overlaps with the Inupiat village's whaling season.
But the bears that come to Kaktovik are climate refugees, on land because the sea ice they rely on for hunting seals is receding.
The Arctic is warming twice as fast as the rest of the planet, and the ice cover is retreating at a pace that even the climate scientists who predicted the decline find startling.
Much of this year was warmer than normal and the freeze-up came late. Last month, the extent of Arctic sea ice was lower than ever recorded for that month.
In the southern Beaufort Sea, where Kaktovik's 260 residents occupy 2.6 sq km on the north-east corner of Barter Island, sea ice loss has been especially precipitous.
The continuing loss of sea ice does not bode well for polar bears, an apex predator that has become the poster animal for climate change.
Few scientists dispute that in the long run, polar bears are in trouble.
A 2015 assessment for the International Union for Conservation of Nature's Red List projected a reduction of more than 30 per cent in the number of polar bears by 2050.
But the effect of climate change in the shorter term is less clear-cut, and a population-wide decline is not yet apparent.
Numbers aside, scientists are seeing other more subtle indicators that the species is at increasing risk, including changes in the bears' physical condition, body size, reproduction and survival rates. And scientists have linked some of these changes to a loss of sea ice and an increase in ice-free days in the areas where the bears live. "It's not going to happen in a smooth, linear way," said Mr Eric Regehr, a biologist at the federal Fish and Wildlife Service in Anchorage who took part in the assessment last year.
Even a few decades ago, most polar bears in the southern Beaufort Sea remained on the ice year- round or, if they did come to shore, stopped only briefly. The sea ice gave them ready access to seals.
But as the climate has warmed, the spring thaw has come earlier and the autumn freeze later. As a result, researchers have found that a larger proportion of the bears in the southern Beaufort region are choosing to spend time on shore.
In the southern Beaufort Sea and in the western Hudson Bay, bears are going into the winter skinnier and in poorer condition.
They are also smaller. And older and younger bears are less likely to survive than in the past. "You see it reflected through the whole population," said Prof Andrew Derocher, professor of biological sciences at the University of Alberta, who has studied polar bears for 32 years. "They just don't grow as fast, and they don't grow as big."
In Kaktovik, at least for now, whales are providing the bears with an alternative source of food. But dead whale is not a polar bear's preferred cuisine.
"The bears are not here because we hunt whales," said Mr Robert Thompson, an Inupiat guide who owns one of six boats that take tourists to view the bears. "They're here because their habitat has gone away, and it's several hundred miles of open water out there."