Juergen & Christine Sohns / African Wild Dog (Lycaon pictus) group attacking Cape Warthog (Phacochoerus aethiopicus), Tswalu Game Reserve, South Africa

Danny Green / Polar bear (Ursus maritimus) cub ready to jump down from pack ice. Svalbard, Norway, April.

Alex Mustard / School of White collar butterflyfish (Chaetodon collare) pack together above a coral reef. North Male Atoll, Maldives. Indian Ocean

Sven Zacek / Bearded seal (Erignathus barbatus) sunbathing on iceberg broken off from glacier. Kongsfjorden fjord, Spitsbergen, Norway. June 2014.

Nick Garbutt / Pack of wolves (Canis lupus). Yellowstone National Park, Wyoming, USA. January.

Daniel J. Cox / Gray Wolf (Canis lupus) pack on ridge in winter, Lamar Valley, Yellowstone National Park, Wyoming

Andy Rouse / Polar bear (Ursus maritimus) standing on pack ice at the water's edge, Svalbard, Norway. June.

Frederique Olivier / Group of Adelie penguins (Pygoscelis adeliae) diving from the edge of the sea ice, Antarctica.

Frederique Olivier / Group of Adelie penguins (Pygoscelis adeliae) walking away from the camera on sea ice at sunset, with one solitary penguin in the foreground, Antarctica.

Frederique Olivier / Group of Adelie penguins (Pygoscelis adeliae) running and gathered on sea ice, Antarctica.

Frederique Olivier / Adelie penguin (Pygoscelis adeliae) colony, with icebergs and pack ice in the background, Antarctica.

Ingo Arndt / Harp seal (Phoca groenlandicus) pup on sea ice looking down into icy water, Magdalen Islands, Gulf of St Lawrence, Quebec, Canada, March.

Ingo Arndt / Harp seal (Phoca groenlandicus) pup sleeping on sea ice, Magdalen Islands, Gulf of St Lawrence, Quebec, Canada, March.

Eric Baccega / Pack of Grey wolves (Canis lupus) howling in the snow, captive. Bavarian Forest National Park, Germany, March. Captive.

Eric Baccega / Pack of Grey wolves (Canis lupus) greeting one another and expressing submissive behaviour,captive, Bavarian Forest National Park, Germany, July. Captive.

Ingo Arndt / Polar Bear (Ursus maritimus) on icefield with moon in late winter, Svalbard, Spitsbergen, Norway, April

Wim van den Heever / White tailed sea eagle (Haliaeetus albicilla) feeding on fish on pack ice, Hokkaido, Japan, February.

Wim van den Heever / White tailed sea eagle (Haliaeetus albicilla) in flight landing, Hokkaido, Japan, February.

Wim van den Heever / Steller's sea-eagle (Haliaeetus pelagicus) standing on pack ice, Hokkaido, Japan, February.

Wim van den Heever / Steller's sea-eagle (Haliaeetus pelagicus) landing on pack ice, Hokkaido, Japan, February.

Ole Jorgen Liodden / Polar bear (Ursus maritimus) standing on ice floe, looking at camera. Svalbard, Norway. August.

Will Burrard-Lucas / Ethiopian wolves (Canis simensis) individual from the BBC pack greeting each other after returning from hunting, Ethiopia.

Ole Jorgen Liodden / Polar bear (Ursus maritimus) walking across vast ice floe, Spitsbergen, Svalbard, July 2013.

Steven Kazlowski / Polar bear (Ursus maritimus) curious young bear approaches over newly forming pack ice during autumn freeze up, Beaufort Sea, off Arctic coast, Alaska

Steven Kazlowski / Polar bear (Ursus maritimus) curious young bear approaching camera, over newly forming pack ice during autumn freeze up, Beaufort Sea, off Arctic coast, Alaska

Steven Kazlowski / Polar bear (Ursus maritimus) young bear rolling around in the snow, on newly formed pack ice during autumn freeze up, Beaufort Sea, off Arctic coast, Alaska

Steven Kazlowski / Polar bear (Ursus maritimus) juvenile crossing over newly forming pack ice, during autumn freeze up, Beaufort Sea, off Arctic coast, Alaska

Ben Cranke / Steller's Sea Eagle (Haliaeetus pelagicus) stood on ice floe, Hokkaido, Japan. February.

Jabruson Motion / THIS VIDEO CLIP WILL BE AVAILABLE TO VIEW ONLINE SOON. TO VIEW NOW, PLEASE CONTACT US. - Agile mangabey (Cercocebus agilis) on top of bushmeat pack with other mangabey limbs and hands and Blue Duiker...

Ingo Arndt / Harp Seal (Phoca groenlandicus) pup on ice, Magdalen Islands, Gulf of Saint Lawrence, Quebec, Canada

Steven Kazlowski / Polar bear (Ursus maritimus) curious young boar on the newly frozen pack ice reaches for remote camera with paw, Beaufort Sea, off the 1002 area of the Arctic National Wildlife Refuge, North Slope, Al...

Steven Kazlowski / Polar bear (Ursus maritimus) curious young male on the newly frozen 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) 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 / Polar bear (Ursus maritimus) 3-year-olds play fighting 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) 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) 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 / Polar bear (Ursus maritimus) investigating camera on pack ice 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) investigating camera on pack ice off the 1002 area of the Arctic National Wildlife Refuge, North Slope of the Brooks Range, Alaska, Beaufort Sea, autumn

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

Florian Möllers / Wolf (Canis lupus) pack running in deep snow, captive in enclosure of the Bavarian Forest National Park, Germany, February

Tony Heald / African Wild Dog (Lycaon pictus) pack passing infront of large African elephant (Loxodonta africana) Mana Pools National Park, Zimbabwe October 2012

Christophe Courteau / Fighting between a pack of 21 African Wild Dogs {Lycaon pictus} and the dominant female of a clan of Spotted Hyaenas (Crocuta crocuta) Northern Okavango Delta, Botswana

Christophe Courteau / Fighting between a pack of 21 African Wild Dogs {Lycaon pictus} and the dominant female of a clan of Spotted Hyaenas (Crocuta crocuta) Northern Okavango Delta, Botswana

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

Jeff Rotman / Whitetip reef sharks (Triaenodon obesus) pack silhouetted following scent trail in water column, Cocos Island, Costa Rica, Pacific Ocean

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

Chadden Hunter / Aerial view of hunting pack of Timber wolves (Canis lupus) in Arctic circle in Northern Canada, Taken on location for BBC Frozen Planet series, 2009

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.

Frederique Olivier / Killer whale (Orcinus orca) amongst thick pack ice, Antarctica. Taken on location for the BBC series, Frozen Planet.

Juergen Freund / A massive workforce of more than 300 women debone Milkfish (Chanos chanos) and pack them on ice. 60% for export market, mainly the Filipino communities living in North America and 40% consumed locall...

Andy Rouse / Polar Bear (Ursus maritimus) large male on pack ice. 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.

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

Suzi Eszterhas / African Wild Dog (Lycaon pictus) pack attacking Warthog (Phacochoerus africanus), northern Botswana

Suzi Eszterhas / African Wild Dog (Lycaon pictus) pack attacking Warthog (Phacochoerus africanus), northern Botswana

Suzi Eszterhas / African Wild Dog (Lycaon pictus) pack attacking Warthog (Phacochoerus africanus), northern Botswana

Suzi Eszterhas / African Wild Dog (Lycaon pictus) pack attacking Warthog (Phacochoerus africanus), northern Botswana

Anup Shah / Pack of Black-backed jackals (Canis mesomelas) scavenging on the remains of a carcass left by African lions ( Panthera leo) Masai Mara National Reserve, Kenya. March.

Andy Rouse / Polar Bear (Ursus maritimus) sitting on pack ice, Svalbard, Norway, September 2009

Andy Rouse / Polar Bear (Ursus maritimus) on pack ice, Svalbard, Norway, September 2009

Andy Rouse / Polar bear (Ursus maritimus) on pack ice, walking head on, Svalbard, Norway (non-ex) September 2007

Andy Rouse / Polar bear (Ursus maritimus) on broken up pack ice, Svalbard, Norway, September 2009

Andy Rouse / Polar bear (Ursus maritimus) on broken pack ice with faint rainbow behind, Svalbard, Norway, February 2009

Andy Rouse / Polar bear (Ursus maritimus) on pack ice, Svalbard, Norway (non-ex) September 2007

Steven Kazlowski / Pair of Arctic foxes (Vulpes / Alopex lagopus) one adult in its winter coat and one pup in its summer coat, play vigorously on the pack ice, 1002 area of the Arctic National Wildlife Refuge, Alaska, O...

Steven Kazlowski / Two Arctic foxwa (Vulpes / Alopex lagopus) play on pack ice off the Arctic coast, 1002 area of the Arctic National Wildlife Refuge, Alaska, October 2008

Steven Kazlowski / Polar bear (Ursus maritimus) cub chases an Arctic fox (Vulpes / Alopex lagopus) on the pack ice to practice its hunting skills, 1002 area of the Arctic National Wildlife Refuge, Beaufort Sea, Alaska,...

Steven Kazlowski / Polar bear (Ursus maritimus) two years, plays with a spring cub on newly formed pack ice along the Arctic coast, Arctic National Wildlife Refuge, Beaufort Sea, Alaska, October 2008

Steven Kazlowski / Spring cub Polar bear (Ursus maritimus) jumping from newly forming pack ice, Arctic coast, Arctic National Wildlife Refuge, Beaufort Sea, Alaska, Autumn, October 2008

Steven Kazlowski / Two Polar bear (Ursus maritimus) spring cubs playing in and around newly forming pack ice along the Arctic coast, 1002 area of the Arctic National Wildlife Refuge, Beaufort Sea, Alaska, Autumn, Octobe...

Steven Kazlowski / Two Polar bear (Ursus maritimus) spring cubs play in and around newly forming pack ice along the Arctic coast, 1002 area of the Arctic National Wildlife Refuge, Beaufort Sea, Alaska, Autumn, October 2...

Steven Kazlowski / Two Polar bear (Ursus maritimus) spring cubs play vigorously on newly forming pack ice along the Arctic coast, Arctic National Wildlife Refuge, Beaufort Sea, Alaska, Autumn, October 2008

Steven Kazlowski / Two Polar bear (Ursus maritimus) spring cubs playing in and around newly forming pack ice along the Arctic coast, 1002 area of the Arctic National Wildlife Refuge, Beaufort Sea, Alaska, Autumn, Octobe...

Steven Kazlowski / Polar bear (Ursus maritimus) spring cub jumping across newly forming pack ice, Arctic coast, Arctic National Wildlife Refuge, Beaufort Sea, Alaska, October 2008

Steven Kazlowski / Inupiaq subsistence hunter dragging Ringed seal (Phoca hispida) catch on the pack ice near Point Hope, Alaska, Chukchi Sea, March 2008

Steven Kazlowski / Young Inupiaq woman with Sheefish (Stenodus leucichthys nelma) caught through a hole in pack ice over the Chukchi Sea, for the village elders of Kotzebue, Alaska, March 2008

Steven Kazlowski / Inupiaq subsistence hunter resting after dragging Ringed seal (Phoca hispida) catch on the pack ice near Point Hope, Alaska, Chukchi Sea, March 2008

Carol Walker / Cowboy leading Quarter horses pack train in the snow at Flitner Ranch, Shell, Wyoming, USA. Model released.

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) curious cub in newly forming pack ice checks out the photographer as the mother sits on shore, Arctic Alaska

Steven Kazlowski / Polar bear (Ursus maritimus) cub in newly forming pack ice with the mother sitting on the shore, Arctic coast, Alaska

Steven Kazlowski / walrus, Odobenus rosmarus, resting on pack ice during spring breakup, Chukchi Sea, off the National Petroleum Reserves, Alaska

Steven Kazlowski / Polar bear (Ursus maritimus) cub rolling around on the pack ice, holdind its head. Arctic National Wildlife Refuge, Alaska

Flip Nicklin / Bottlenose Dolphin (Tursiops truncatus) with plastic six pack holder in mouth, Hawaii

Mark Raycroft / Alaskan Malamute (Canis familiaris) in snow wearing pack

Pete Cairns / European wolf pack (Canis lupus) feeding on red deer carcass in winter, Captive, Scotland, UK.

Staffan Widstrand / Polar bear {Ursus maritimus} on pack ice, Churchill, Canada.

Jim Brandenburg / Arctic Wolf (Canis lupus) pack hunting Muskox (Ovibos moschatus) herd, Ellesmere Island, Nunavut, Canada

Mitsuaki Iwago / African Lion (Panthera leo) females killing Burchell's Zebra (Equus burchellii), Serengeti National Park, Tanzania

Richard Du Toit / African elephant sprays itself with mud {Loxodonta africana} Linyanti, Botswana, Southern Africa. The mud-pack, when dry, forms a hard crust that deters insect attacks.

Yva Momatiuk & John Eastcott / Timber Wolf (Canis lupus) members of the pack in mock fight, Grizzly Discovery Center, Montana