Steven Kazlowski / Young Polar bear (Ursus maritimus) standing and trying to balance in shallow water along the Bernard Spit, 1002 area of the Arctic National Wildlife Refuge, North Slope of the Brooks Range, Alaska, Oc...

Steven Kazlowski / Young Polar bear (Ursus maritimus) standing and trying to balance in shallow water along the Bernard Spit, 1002 area of the Arctic National Wildlife Refuge, North Slope of the Brooks Range, Alaska, Oc...

Steven Kazlowski / Young Polar bear (Ursus maritimus) standing and trying to balance in shallow water along the Bernard Spit, 1002 area of the Arctic National Wildlife Refuge, North Slope of the Brooks Range, Alaska, Oc...

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

Andy Rouse / Polar Bear (Ursus maritimus) portrait in sea-ice landscape. Wide angle / fish-eye shot. Svalbard, Norway, September.

Steven Kazlowski / Polar bear (Ursus maritimus) on sea ice, off the coast of Svalbard, Norway

Steven Kazlowski / Polar bear (Ursus maritimus) mother with cub, newly emerged from their den on the Arctic coast, eastern Arctic National Wildlife Refuge, Alaska

Staffan Widstrand / Polar Bear (Ursus maritimus) mobbed by possibly a Skua, Svalbard, Norway, July

Staffan Widstrand / Polar Bear (Ursus maritimus) head portrait with blue tongue out, Svalbard, Norway

Staffan Widstrand / Polar Bear (Ursus maritimus) reflection in water, Svalbard, Norway

Staffan Widstrand / Polar Bear (Ursus maritimus) head portrait with blue tongue sticking out, Svalbard, Norway

Mark Carwardine / Polar bear swimming {Ursus maritimus} Nunavut, Canada

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 / Polar bear (Ursus maritimus) underwater view swimming in a pool, Anchorage Zoo, Alaska, USA. No release available.

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

Andy Rouse / Polar bear (Ursus arctos maritimus) mother rolling in snow watched by new year cubs, 6 months old, Svalbard, Arctic

Andy Rouse / Polar bear (Ursus maritimus) standing against expedition ship, taken with extreme wide angle lens, Svalbard, Arctic September 2011

Andy Rouse / Polar bear (Ursus maritimus) on pack ice taken with fisheye lens, Svalbard, Arctic September 2011

Steven Kazlowski / Young Polar bear (Ursus maritimus) in the water along the coast of the Beaufort Sea, Bernard Spit, off the 1002 area of the Arctic National Wildlife Refuge, North Slope of the Brooks Range, Alaska, Oc...

Steven Kazlowski / Young Polar bear (Ursus maritimus) standing and trying to balance in shallow water along the Bernard Spit, 1002 area of the Arctic National Wildlife Refuge, North Slope of the Brooks Range, Alaska, Oc...

Steven Kazlowski / Portrait of Polar bear (Ursus maritimus) cub along the Bernard Spit during autumn freeze up, 1002 area of the Arctic National Wildlife Refuge, North Slope of the Brooks Range, Alaska, October 2011

Steven Kazlowski / Young Polar bear (Ursus maritimus) traveling across newly formed pack ice during autumnal freeze up, off the 1002 area of the Arctic National Wildlife Refuge, North Slope of the Brooks Range, Alaska,...

Erlend Haarberg / Brown bear (Ursus arctos) at forest edge, Ovre-Pasvik National Park, Finnmark, Norway, May

Roy Mangersnes / Polar bear (Ursus maritimus) holding piece of ice after licking off freshwater, Spitsbergen, Svalbard, Norway, August

Roy Mangersnes / Polar bear (Ursus maritimus) foot sticking out of water while diving for food, Spitsbergen, Svalbard, Norway, August

Roy Mangersnes / Polar bear (Ursus maritimus) sitting with dark blue tongue showing, Spitsbergen, Svalbard, Norway, August

Roy Mangersnes / Female Polar bear (Ursus maritimus) and cub on coastal rocks near Whale skeleton, Spitsbergen, Svalbard, Norway, August

Andy Rouse / Polar Bear (Ursus maritimus) in snowstorm. Spitsbergen, Norway. Non-excusive.

Andy Rouse / Polar Bear (Ursus maritimus) crossing pack ice. Svalbard, Norway, September.

Andy Rouse / Polar Bear (Ursus maritimus) portrait on pack ice. Svalbard, Norway, September.

Andy Rouse / Polar Bear (Ursus maritimus) sleeping on pack ice. Wide angle / fish-eye shot. Svalbard, Norway, September.

Andy Rouse / Polar Bear (Ursus maritimus) sleeping on ice. Svalbard, Norway, September.

Ole Jorgen Liodden / Polar Bear (Ursus maritimus) sitting on floe in vast thawing sea-ice landscape. Spitsbergen, Svalbard, August 2011. Second place, Mammals Category, GDT 2012 competion. Winner in ANIMALS IN THEIR ENVIR...

Ole Jorgen Liodden / Polar Bear (Ursus maritimus) in arctic ice landscape backlit by midnight sun. Nordaustlandet, Svalbard, August.

Ole Jorgen Liodden / Polar Bear (Ursus maritimus) with blooded face looking at Glaucous Gull (Larus hyperboreus) in flight. Spitsbergen, Svalbard, July.

Ole Jorgen Liodden / Polar Bear (Ursus maritimus) looking across ice floe seascape. Nordaustlandet, Svalbard, August.

Ole Jorgen Liodden / Polar Bear (Ursus maritimus) profile in silhouette. Nordaustlandet, Svalbard, August.

Jenny E. Ross / Polar Bear (Ursus maritimus) sub-adult male on cliff searching for eggs in Brunnich's Guillemot nests, as gulls look on from above. This unusual behaviour happens when when lack of sea-ice prevents t...

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 adult investigates a remote camera along a hillside on Spitsbergen and the northwest coast of the Svalbard Archipelago, Norway, Greenland Sea, July

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

Eric Baccega / Polar Bear (Ursus maritimus) mother with her 3-month cub, soon after emerging from their hibernation den. Wapusk National Park, Manitoba, Canada, March.

Eric Baccega / Polar Bear (Ursus maritimus) mother resting while her 3-month cubs play. Wapusk National Park, Manitoba, Canada, March.

Eric Baccega / Polar Bear (Ursus maritimus) walking on icepack with arctic coast in the background. Floe edge, Arctic Bay, Baffin Island, Nunavut, Canada, April.

Andy Rouse / Polar Bear (Ursus maritimus) mother and two cubs playing around iceberg. Svalbard, Norway, Europe, February.

Andy Rouse / close up portrait of a Polar Bear (Ursus maritimus), about three year. Svalbard, Norway, Europe, February.

Andy Rouse / Polar Bear (Ursus maritimus) large male on pack ice. Svalbard, Norway, Europe, February.

Andy Rouse / Polar Bear (Ursus maritimus) mother standing on hind legs, and cub (18 months old). Svalbard, Norway, Europe, February.

Andy Rouse / Two Polar Bears (Ursus maritimus) swimming. Svalbard, Norway, Europe, February.

Andy Rouse / Two Polar Bear (Ursus maritimus) new year cubs (6 months). Svalbard, Norway, Europe, February.

Kevin Schafer / Polar bear (Ursus maritimus) resting on pack ice, Svalbard, Arctic Norway, vulnerable species 2010

Kevin Schafer / Polar bear (Ursus maritimus) sitting on pack ice, Svalbard, Arctic Norway, vulnerable species 2010

Bryan and Cherry Alexander / Tourists on icebreaker "Professor Multanovskiy" watching Polar bear (Ursus maritimus) in pack ice. Svalbard, Norway, 2004.

Eric Baccega / Polar bear (Ursus maritimus) female and her two cubs on large iceberg off Baffin Island. Nunavut, Canada, August 2010

Eric Baccega / Polar bear (Ursus maritimus) female and her two cubs on large iceberg off Baffin Island. Nunavut, Canada, August 2010

Eric Baccega / Polar bear (Ursus maritimus) female and her two cubs on an iceberg, off Baffin Island. Nunavut, Canada, August 2010

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 / Polar bears (Ursus maritimus) female with cubs aged two years travelling along a barrier island during autumn freeze up, Bernard Spit, 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) young male playing / rolling around in the snow along a barrier island during autumn freeze up, Bernard Spit, 1002 area of the Arctic National Wildlife Refuge, Alaska

Steven Kazlowski / Polar bear (Ursus maritimus) portrait of curious young male, covered in snow from rolling around / playing. On a barrier island during autumn freeze up, Bernard Spit, 1002 area of the Arctic National...

Steven Kazlowski / Polar bear (Ursus maritimus) young boar playing / rolling around in the snow along a barrier island during autumn freeze up, Bernard Spit, 1002 area of the Arctic National Wildlife Refuge, Alaska

Steven Kazlowski / Two Polar bear (Ursus maritimus) newborn cubs playing outside their den, mouth of Canning River along the Arctic coast, eastern Arctic National Wildlife Refuge, Alaska

Steven Kazlowski / Polar bear (Ursus maritimus) sow with newborn spring cub newly emerged from their den, mouth of Canning River along the Arctic coast, eastern Arctic National Wildlife Refuge, Alaska

Steven Kazlowski / Polar bear (Ursus maritimus) head portrait of adult scenting the wind, Arctic National Wildlife Refuge, Alaska

Steven Kazlowski / Polar bear (Ursus maritimus) juvenile shaking off snow after rolling around on the pack ice, arctic coast, 1002 area of the Arctic National Wildlife Refuge, Alaska, Beaufort Sea

Steven Kazlowski / Polar bear (Ursus maritimus) profile portrait of juvenile, Bernard Spit, Arctic National Wildlife Refuge, Alaska

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 / Polar bear (Ursus maritimus) footprints in the snow along a barrier island during autumn freeze up, Bernard Spit, 1002 area of the Arctic National Wildlife Refuge, Alaska. October 2009

Steven Kazlowski / Polar bear (Ursus maritimus) portrait of a juvenile male playing in the slushy freezing water, Bernard Spit, 1002 area of the Arctic National Wildlife Refuge, Alaska.

Nick Garbutt / Adult Polar bear (Ursus maritimus) at sunset on tundra vegetation on shores of Hudson Bay, Canada (late Sept). Digitally Modified.

Bryan and Cherry Alexander / Polar bear (Ursus maritimus) getting covered in snow as he sleeps. Cape Churchill, Canada.

Bryan and Cherry Alexander / Polar bear (Ursus maritimus) on sea ice in wind. Churchill, Manitoba, Canada.

Bryan and Cherry Alexander / Polar bear (Ursus maritimus) mother and cubs with Parhelion / sun dogs over sea ice. Churchill, Manitoba, Canada.

Bryan and Cherry Alexander / Young Polar bear (Ursus maritimus) investigating tripod. Cape Churchill, Canada.

Steven Kazlowski / Polar bear (Ursus maritimus) traveling along the coast on sea ice in search of seals, Svalbard, Norway

Steven Kazlowski / Female Polar bear (Ursus maritimus) curiously checks out the photographer, standing upright on hind legs, Svalbard, Norway

Steven Kazlowski / Portrait of polar bear (Ursus maritimus) travelling across melting sea ice in search of seals, Svalbard, Norway

Steven Kazlowski / Portrait of Polar bear (Ursus maritimus) sow standing with her cub on the snow in late winter, Arctic coast of Alaska

Steven Kazlowski / Polar bear (Ursus maritimus) sow standing with her cub outside their den in late winter, Arctic coast of Alaska

Steven Kazlowski / Polar bear (Ursus maritimus) sow with her cub outside their den in late winter, Arctic coast of Alaska, USA

Steven Kazlowski / Polar bear (Ursus maritimus) sow with her cub outside their den in late winter, Arctic coast of Alaska

Steven Kazlowski / Polar bear (Ursus maritimus) sow plays with her spring cub outside their den in late winter, Alaska

Steven Kazlowski / Polar bear (Ursus maritimus) sow plays with her spring cub outside their den in late winter, Alaska

Steven Kazlowski / Polar bear (Ursus maritimus) sow plays with her spring cub outside their den in late winter, Alaska

Steven Kazlowski / Portrait of Polar bear (Ursus maritimus) sow with spring cub, newly emerged from their den in late winter, Arctic coast, Alaska, USA

Steven Kazlowski / Polar bear (Ursus maritimus) sow with spring cub, newly emerged from their den in late winter, Arctic coast, Alaska, USA

Eric Baccega / Two Polar bears (Ursus maritimus) standing upright, fighting, Churchill, Manitoba, Canada

Nick Garbutt / Adult Polar bear (Ursus maritimus) at sunset, Shores of Hudson Bay, Canada, late September, digitally modified

Matthias Breiter / Polar Bear (Ursus maritimus) cooling off on a frozen lake, Churchill, Manitoba, Canada

Steven Kazlowski / Polar bear (Ursus maritimus) sow jumping while hunting for seals on sea ice, off the coast of Svalbard, Norway

Wild Wonders of Europe / Liodden / Polar bear (Ursus maritimus) in front of glacier, Spitsbergen, Svalbard, Norway, March 2009. BOOK & WWE OUTDOOR EXHIBITION. Wild Wonders kids book.

Wild Wonders of Europe / de la Lez / Polar bear (Ursus maritimus) portrait, Svalbard, Norway, July 2008

Wild Wonders of Europe / de la Lez / Polar bear (Ursus maritimus) leaping from sea ice, Moselbukta, Svalbard, Norway, July 2008