Heather Angel / Giant panda (Ailuropoda melanoleuca) sliding down slope on back after losing footing. Panda Breeding Centre, Wolong, Sichuan, China. January 1987.

Ismaele Tortella / Eurasian otter (Lutra lutra) hunting in a shoal of Atlantic herring (Clupea harengus), northern Norway, March

Ismaele Tortella / Four Eurasian elk (Alces alces) walking through vegetation , Norway, August

Ismaele Tortella / Svalbard reindeer (Rangifer tarandus platyrhynchus) feeding in snow, Svalbard, Norway, March.

Ismaele Tortella / Reindeer (Rangifer tarandus), Kvaloya island, Tromso, Norway, November.

Morley Read / Opossum (Marmosa sp.) on the branch of a rainforest shrub at night, Pastaza Province, Ecuadorian Amazon.

Bence Mate / European rabbits (Oryctolagus cuniculus) fighting each other, Kiskunsag National Park, Hungary. June. Winner, General Fauna Category, 2019 Cadiz Photo Nature Competition.

Andy Rouse / African lion (Panthera leo) female carrying young cub, Masai Mara, Kenya, Africa. Highly commended in the African Wildlife Category of the Nature's Best Photography Competition 2019.

Diane McAllister / Polar bears (Ursus maritimus) fighting in water. Beaufort Sea , Kaktovik Alaska. USA. Highly commended in the Polar Passion category of the Nature's Best Photography Competition 2019.

Claudio Contreras / Californian sea lion (Zalophus californianus) swimming in Southern sea palm (Eisenia arborea) and Giant Kelp (Macrocystis pyrifera) forest, San Benitos Islands, Baja California Pacific Islands Biosphe...

Ann & Steve Toon / RF - Lion (Panthera leo) head portrait at night, Zimanga private game reserve, KwaZulu-Natal, South Africa. (This image may be licensed either as rights managed or royalty free.)

Danny Green / Polar bear (Ursus maritimus) walking across sea ice, reflected in water. Svalbard, Norway, July.

Danny Green / Polar bear (Ursus maritimus) female resting with cubs on glacier. Svalbard, Norway, July.

Danny Green / Polar bear (Ursus maritimus) female and cubs feeding on Whale carcass. Svalbard, Norway, July.

Danny Green / Polar bear (Ursus maritimus) and two cubs feeding on Whale carcass. Svalbard, Norway, July.

Danny Green / Polar bear (Ursus maritimus) and cubs, standing on sea ice. Svalbard, Norway, July.

Danny Green / Polar bear (Ursus maritimus) and cubs resting on sea ice. Svalbard, Norway, July.

Danny Green / Polar bear (Ursus maritimus) female and cubs, one cub walking up slope of ice in foreground. Svalbard, Norway, July.

Danny Green / Polar bear (Ursus maritimus) and cubs feeding on Whale carcass. Svalbard, Norway, July.

Danny Green / Polar bear (Ursus maritimus) and cubs feeding on Whale carcass, on iceberg. Svalbard, Norway, July 2018.

Danny Green / Polar bear (Ursus maritimus) walking across ice, snow covered mountain in background. Svalbard, Norway, April 2018.

Danny Green / Polar bear (Ursus maritimus) resting in snow. Svalbard, Norway, July.

Danny Green / Polar bear (Ursus maritimus) licking paw, close-up. Svalbard, Norway, April.

Danny Green / Polar bear (Ursus maritimus) standing on glacier. Svalbard, Norway, July 2018.

Danny Green / Polar bear (Ursus maritimus) standing on ice. Svalbard, Norway, July.

Danny Green / Polar bear (Ursus maritimus) looking for food on ice. Svalbard, Norway, April.

Danny Green / Polar bear (Ursus maritimus) male standing beside rocks in frozen and snow covered landscape. Svalbard, Norway, April 2019.

Danny Green / Polar bear (Ursus maritimus) male walking across frozen landscape. Svalbard, Norway, April 2019.

Danny Green / Polar bear (Ursus maritimus) male in snow. Svalbard, Norway, April.

Danny Green / Polar bear (Ursus maritimus), male and female approaching each other across snow covered rocky landscape. Svalbard, Norway, April 2019.

Danny Green / Polar bear (Ursus maritimus) male approaching female on snow covered hill top. Svalbard, Norway, April 2019.

Danny Green / Polar bear (Ursus maritimus) male approaching female in rocky area covered in snow. Svalbard, Norway, April 2019.

Danny Green / Arctic fox (Vulpes lagopus), two in snow covered landscape. Svalbard, Norway, April 2019.

Danny Green / RF - Polar bear (Ursus maritimus) male walking through snow covered landscape, mountains in background. Svalbard, Norway, April (This image may be licensed either as rights managed or royalty free.)

Danny Green / RF - Reindeer (Rangifer tarandus) walking up slope in snow. Svalbard, Norway, April. (This image may be licensed either as rights managed or royalty free.)

Danny Green / RF - Polar bear (Ursus maritimus) cub walking in snow. Svalbard, Norway, April. (This image may be licensed either as rights managed or royalty free.)

Danny Green / RF - Polar bear (Ursus maritimus) female walking across ice. Svalbard, Norway, April. (This image may be licensed either as rights managed or royalty free.)

Danny Green / Ringed seal (Pusa hispida) and pup resting on ice. Svalbard, Norway. April.

Danny Green / Reindeer (Rangifer tarandus), two standing on ridge in blizzard. Svalbard, Norway. April.

Danny Green / Reindeer (Rangifer tarandus), two play fighting in snow. Svalbard, Norway, April.

Danny Green / Reindeer (Rangifer tarandus), two standing on ridge in snow. Svalbard, Norway, April.

Danny Green / Reindeer (Rangifer tarandus) standing on ridge in snow, another reindeer in background. Svalbard, Norway, April.

Danny Green / Reindeer (Rangifer tarandus) hunkering down in snow during blizzard. Svalbard, Norway, April.

Danny Green / Reindeer (Rangifer tarandus) walking in snow. Svalbard, Norway, April.

Danny Green / Polar bear (Ursus maritimus) female and cubs play fighting. Svalbard, Norway, March 2018.

Danny Green / Polar bear (Ursus maritimus) two walking in snowy landscape. Svalbard, Norway, April 2018.

Danny Green / Polar bear (Ursus maritimus) male female pair looking upwards, snow covered hills in background. Svalbard, Norway, April 2018.

Danny Green / Polar bear (Ursus maritimus) group on ice, female and cubs feeding on Whale carcass. Svalbard, Norway, June 2018.

Danny Green / Polar bear (Ursus maritimus) resting on sea ice, view from above. Svalbard, Norway, June 2018.

Danny Green / Polar bear (Ursus maritimus) sleeping in snow. Churchill, Manitoba, Canada, November.

Danny Green / Polar bear (Ursus maritimus) hunting Seal on sea ice. Svalbard, Norway, July 2018.

Danny Green / Polar bear (Ursus maritimus), two cubs playing, leaping across sea ice, reflected in water. Svalbard, Norway, July.

Danny Green / Polar bear (Ursus maritimus), two cubs walking on sea ice. Svalbard, Norway, July.

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

Danny Green / Ringed seal (Pusa hispida) resting on ice, reflected in water. Svalbard, Norway. July.

Daniel Heuclin / Llama (Lama glama) Laguna colorada. Altiplano, Bolivia.

Daniel Heuclin / Llama (Lama glama) herd, Laguna colorada. Altiplano, Bolivia.

Nick Garbutt / Puma (Puma concolor puma) young male standing with mouth open. Estancia Amarga, near Torres del Paine National Park, Patagonia, Chile. December.

Nick Garbutt / Western red panda (Ailurus fulgens fulgens) climbing in tree. Singalila National Park, India / Nepal border.

Nick Garbutt / American bison (Bison bison) female covered in hoar frost near hot spring, portrait. Midway Geyser Basin, Yellowstone National Park, USA. February.

Nick Garbutt / RF - Red fox (Vulpes vulpes) foraging in snow covered valley. Hayden Valley, Yellowstone National Park, USA. February 2019. (This image may be licensed either as rights managed or royalty free.)

Gabriel Rojo / Guanaco (Lama guanicoe) female and newborn baby, nose to nose in grassland. La Pampa Province, Argentina.

Tony Wu / Bowhead whale (Balaena mysticetus), group socialising in shallow water, aerial view. Part of larger group of more than 50 whales congregating, Sea of Okhotsk sub-population, Russia.

Ann & Steve Toon / Cheetah (Acinonyx jubatus) walking, silhouetted at dusk. Zimanga private game reserve, KwaZulu-Natal, South Africa.

Ann & Steve Toon / African elephants (Loxodonta africana) herd silhouetted at sunset. Chobe National Park, Botswana.

Will Burrard-Lucas / White rhino (Ceratotherium simum), portrait. Solio Game Reserve, Solio Ranch, Kenya. Taken with remote camera buggy / BeetleCam.

Alex Mustard / Dugong (Dugong dugon) male and juvenile Golden trevally (Gnathanodon speciosus) swimming over Seagrass (Halophila stipulacea) meadow. Marsa Nabaa, Marsa Alam, Egypt.

Alex Mustard / Spinner dolphin (Stenella longirostris) pod socialising close to surface. Fury Shoal, Sataya Reef, Marsa Alam, Egypt.

Felis Images / Asiatic lion (Panthera leo persica), female and cubs in morning light, cub biting mother's leg. Gir National Park, Gujarat, India. Photo Phillip Ross/Felis Images

David Tipling / Grey seal (Halichoerus grypus) female in surf, Horsey, Norfolk, England, UK, February.

David Tipling / Grey seal (Halichoerus grypus) pup, Horsey, Norfolk, England, UK, February.

Tony Wu / Humpback whale (Megaptera novaeangliae australis) female with suckling calf. Vava'u Islands, Tonga.

Tony Wu / Humpback whale (Megaptera novaeangliae australis) male calf playing at ocean surface after coming up to breathe. Vava'u Islands, Tonga.

Tony Wu / Sperm whale (Physeter macrocephalus), ten swimming together in gathering of more than 50 individuals. Whales with flatulence and defecating. Sri Lanka.

Ann & Steve Toon / Meerkats (Suricata suricatta) on the move, Kgalagadi Transfrontier Park, Northern Cape, South Africa, January. Second place in the Mammals Category of the GDT European Nature Photographer of the Year...

Andy Rouse / Bengal tiger (Panthera tigris) male, sub-adult aged three years, face portrait. Ranthambhore National Park, India.

Tony Heald / African wild dog (Lycaon pictus) portrait. Chobe National Park Botswana. Digitally enhanced sepia image.

Tony Heald / Elephant (Loxodonta africana) calves playing, Etosha National Park,Namibia.

Cyril Ruoso / Ringed-tailed lemur (Lemur catta) amongst granite rocks in cave. Lemurs lick minerals from the rocks. Anja Community Reserve, Madagascar.

Staffan Widstrand / African bush elephant, (Loxodonta africana) two head to head playing, Zimanga Private Nature Reserve, KwaZulu Natal, South Africa

Staffan Widstrand / RF - African bush elephant, (Loxodonta africana) at night, reflected in waterhole, South Africa

Bernard Castelein / Coquerel's sifaka (Propithecus coquereli) in tree, relaxing, Ankarafantsika National Park, Madagascar

Bernard Castelein / Silky sifaka (Propithecus candidus) in tree, Marojejy National Park, Madagascar. Critically endagered species.

Heather Angel / Northern white cheeked gibbon (Nomascus leucogenys) female standing in tree with baby aged two weeks. Parents captive bred and released. Wild Elephant Valley / Xishuangbanna, Yunnan Province, China, 2...

Heather Angel / Giant panda (Ailuropoda melanoleuca) portrait, in falling snow. Captive bred, in enclosure, Panda Breeding Centre, Wolong, Sichuan Province, China. February 2008.

Oscar Dewhurst / Fallow deer (Dama dama) walking across frost-covered playing fields at dawn, with tower blocks of London in the background. Richmond Park, London, UK. December

Oscar Dewhurst / Red deer (Cervus elaphus) stag roaring, silhouetted under trees at sunrise. Bushy Park, London, UK. September

Andy Rouse / Bengal Tiger (Panthera tigris) family drinking from pool, Ranthambhore, India

Doug Perrine / Dugong or Sea cow (Dugong dugon) split level view, Calauit Island, off Busuanga, Calamian Islands, Palawan, Philippines.

Jack Dykinga / Bighorm sheep (Ovis canadensis) males grouped together before the rutting season. Valley of Fire State Park, Nevada, USA, February.

Jordi Chias / Humpback whale (Megaptera novaeangliae), Antarctic Peninsula, Antarctica.

Jordi Chias / Crabeater seals (Lobodon carcinophaga) resting on ice floating ice sheet, Antarctic Peninsula, Antarctica.

Jordi Chias / Antarctic fur seal (Arctocephalus gazella), Antarctic Peninsula, Antarctica.

Jordi Chias / Antarctic fur seal (Arctocephalus gazella), Antarctic Peninsula, Antarctica.

Jordi Chias / Crabeater seals (Lobodon carcinophaga), Antarctic Peninsula, Antarctica.

Jordi Chias / Humpback whale (Megaptera novaeangliae) spyhopping, Antarctic Peninsula, Antarctica.