Steven Kazlowski / Two curious young Polar bears (Ursus maritimus), Barter Island, off the 1002 area of the Arctic National Wildlife Refuge, North Slope of the Brooks Range, Alaska, October 2011

Sylvain Cordier / Polar bear (Ursus maritimus), female with two cubs, on a barrier island outside Kaktovik, Alaska, USA.

Matthias Breiter / Polar Bear (Ursus maritimus) mother with cubs on coast, Barter Island, Alaska

Steven Kazlowski / Polar bear (Ursus maritimus) female with cubs aged two years, along a barrier island during fall freeze up, Barter Island, 1002 area of the Arctic National Wildlife Refuge, Alaska

Steven Kazlowski / Photographers photographing of a group of curious Polar bears (Ursus maritimus) from motorboats along a barrier island during autumn freeze up, Barter Island, 1002 area of the Arctic National Wildlife...

Steven Kazlowski / Polar bear (Ursus maritimus) head close-up portrait of an adult male, with snowflakes on fur, Barter Island, 1002 area of the Arctic National Wildlife Refuge, Alaska

Steven Kazlowski / Sun setting as a blizzard freezes the landscape outside the Inupiaq village of Kaktovik, Barter Island, 1002 area of the Arctic National Wildlife Refuge, Alaska, October 2008

Steven Kazlowski / Polar bear (Ursus maritimus) curious cub stands on newly formed autumn pack ice, off Barter Island the the Arctic National Wildlife Refuge, Alaska

Steven Kazlowski / Polar bear {Ursus maritimus} walking through the Arctic coastal village of Kaktovik at night with dogs watching, Barter Island, Alaska.

Sylvain Cordier / Polar bears (Ursus maritimus) two juveniles fighting, along a barrier island outside Kaktovik, Alaska, USA.

Sylvain Cordier / Polar bears (Ursus maritimus) female adult with two cubs, on a barrier island outside Kaktovik, Alaska, USA.

Sylvain Cordier / Polar bears (Ursus maritimus) standing up on hind legs, barrier island outside Kaktovik, Alaska, USA. September.