Steven Kazlowski,Steven Kazlowski / Polar bear (Ursus maritimus) juvenile spreading body weight over thin newly forming pack ice, trying not to break through, Beaufort Sea, off the 1002 area of the Arctic National Wildlife Refuge, North...

Steven Kazlowski,Steven Kazlowski / Polar bear (Ursus maritimus) juvenile rolling around on newly formed pack ice, Beaufort Sea, off the 1002 area of the Arctic National Wildlife Refuge, North Slope, Alaska

Steven Kazlowski,Steven Kazlowski / Polar bear (Ursus maritimus) portrait, female. Bernard Spit, 1002 area of the Arctic National Wildlife Refuge, North Slope, Alaska.

Steven Kazlowski,Steven Kazlowski / Polar bear (Ursus maritimus) curious adult head underwater, Beaufort Sea, off the 1002 area of the Arctic National Wildlife Refuge, North Slope, Alaska.

Steven Kazlowski,Steven Kazlowski / Polar bear (Ursus maritimus) young bear in freezing water during autumn freeze up, Bernard Spit, 1002 area of the Arctic National Wildlife Refuge, North Slope, Alaska, Beaufort Sea

Steven Kazlowski,Steven Kazlowski / Polar bear (Ursus maritimus) 4-5 year-old on pack ice, low angle shot, off the 1002 area of the Arctic National Wildlife Refuge, North Slope of the Brooks Range, Alaska, Beaufort Sea, autumn

Steven Kazlowski / Polar bear (Ursus maritimus) adult walking over newly formed pack ice during fall freeze up, 1002 area of the Arctic National Wildlife Refuge, North Slope, Alaska, USA

Steven Kazlowski / Polar bear (Ursus maritimus) sow and cub sliding on their backs over the pack ice, much like ice skating, 1002 coastal plain of the Arctic National Wildlife Refuge, Alaska, USA

Steven Kazlowski / Grizzly bear (Ursus arctos horribils) walking on snow, 1002 coastal plain, Arctic National Wildlife Refuge, North Slope of Brooks Range, Alaska, USA

Steven Kazlowski / Polar bear (Ursus maritimus) curious cub sits up on its hind legs and tries to balance itself, along Bernard Spit in autumn, 1002 area of the Arctic National Wildlife Refuge, Alaska, USA, October

Steven Kazlowski / Polar bear (Ursus maritimus) curious cub sits up on its hind legs, paw raised, and tries to balance itself, along Bernard Spit in autumn, 1002 area of the Arctic National Wildlife Refuge, Alaska, US...

Steven Kazlowski / Polar bear (Ursus maritimus) curious cub stands along Bernard Spit as its mother and other cub rest in the background, 1002 area of the Arctic National Wildlife Refuge, Alaska, USA, October