Ismaele Tortella / Northern gannet (Morus bassanus) colony, chick climbing back into nest, with the midnight sun, Norway, July

Ismaele Tortella / Tracking shot of a Whooper swan (Cygnus cygnus) family walking, Lofoten, northern Norway, August.

Morley Read / Slow motion clip of a Mute swan (Cygnus olor) with three cygnets, Cornwall, England, UK, May.

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.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) two adults brooding chicks age 5 weeks, Antarctica. Highly commended in the Polar Passion Category of the Nature's Best Photography Awards 2019.

Morley Read / Close-up of Agua rica leaf frog (Phyllomedusa ecuatoriana) eggs after 18 days development, the tadpoles are fully developed and ready to hatch, Ecuador. Endangered.

Morley Read / Close-up of Agua rica leaf frog (Phyllomedusa ecuatoriana) eggs after 11 days development, showing beating heart and blood flowing over gills, Ecuador. Endangered.

Chase Dekker / Humpback Whale (Megaptera novaeangliae) calf breaching, Monterey Bay, California

Chase Dekker / Humpback Whale (Megaptera novaeangliae) calf breaching, Monterey Bay, California

Chase Dekker / Humpback Whale (Megaptera novaeangliae) calf breaching, Monterey Bay, California

Chase Dekker / African Lion (Panthera leo) cub, Masai Mara, Kenya

Gerry Ellis / Chimpanzee (Pan troglodytes) orphan Larry playing in tree, Ape Action Africa, Mefou Primate Sanctuary, Cameroon

Gerry Ellis / Chimpanzee (Pan troglodytes) orphans, Larry investigating Daphne's tongue, Ape Action Africa, Mefou Primate Sanctuary, Cameroon

Gerry Ellis / Chimpanzee (Pan troglodytes) orphan Larry, Ape Action Africa, Mefou Primate Sanctuary, Cameroon

Gerry Ellis / Chimpanzee (Pan troglodytes) orphan Larry playing in forest nursery, Ape Action Africa, Mefou Primate Sanctuary, Cameroon

Gerry Ellis / Chimpanzee (Pan troglodytes) orphan Larry scratching, Ape Action Africa, Mefou Primate Sanctuary, Cameroon

Juergen & Christine Sohns / African Lion (Panthera leo) six week old cubs, Tswalu Game Reserve, South Africa

Juergen & Christine Sohns / African Lion (Panthera leo) six week old cub, Tswalu Game Reserve, South Africa

Anup Shah / Olive Baboon (Papio anubis) male with three month old young, Gombe National Park, Tanzania

Anup Shah / Eastern Chimpanzee (Pan troglodytes schweinfurthii) four year old infant male, named Gizmo, foraging for insects in log, Gombe National Park, Tanzania

Fiona Rogers / Eastern Chimpanzee (Pan troglodytes schweinfurthii) four year old infant male, named Gizmo, Gombe National Park, Tanzania

Fiona Rogers / Eastern Chimpanzee (Pan troglodytes schweinfurthii) four year old infant male, named Gizmo, Gombe National Park, Tanzania

Martin Willis / Budgerigar (Melopsittacus undulatus) father with begging chick at nest cavity, Queensland, Australia

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

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

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

Oscar Dewhurst / Mute swan (Cygnus olor), two cygnets sheltering under parent's wing. Richmond Park, London, England, UK. April.

Oscar Dewhurst / Mute swan (Cygnus olor) swimming with cygnets in misty lake in morning light. Richmond Park, London, England, UK. May.

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) 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.

Jack Dykinga / Burrowing owl (Athene cunicularia) female and ten chicks aged a few weeks. Marana, Arizona, USA. May.

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

Ingo Arndt / Mountain Lion (Puma concolor) mother and four month old cubs playing, Torres del Paine National Park, Patagonia, Chile. Highly commended in the Animal Portraits Category of the Wildlife Photographer o...

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) egg hatching on father's feet. Atka Bay, Antarctica. August. Winner of the Portfolio category of the Wildlife Photographer of the Year Awards 2019.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) chick looking upwards to parents beak. Atka Bay, Antarctica. August. Winner of the Portfolio category of the Wildlife Photographer of the Year Awards 2019.

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...

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

Jordi Chias / Chinstrap penguin (Pygoscelis antarcticus) with chicks, Antarctic Peninsula, Antarctica.

Jordi Chias / Gentoo penguin (Pygoscelis papua) feeding chick, Antarctic Peninsula, Antarctica.

Jordi Chias / Gentoo penguin (Pygoscelis papua) feeding chick, Antarctic Peninsula, Antarctica.

Jordi Chias / Gentoo penguin (Pygoscelis papua) with chick, Port Charcot, Antarctic Peninsula, Antarctica.Antarctic Peninsula, Antarctica.

Jordi Chias / Humpback whale (Megaptera novaeangliae), adult and baby at surface, Antarctic Peninsula, Antarctica.

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

Ingo Arndt / Female Puma (Puma concolor) with two cubs aged around four months, Torres del Paine National Park, Patagonia, Chile, July.

Mark Raycroft / Woodland Caribou (Rangifer tarandus caribou) mother nursing calf, Newfoundland, Canada

Alex Mustard / California sea lion (Zalophus californianus) pups in an underwater cave. Los Islotes, La Paz, Baja California Sur, Mexico. Sea of Cortez, Gulf of California, East Pacific Ocean.

Ernie Janes / Celebes crested macaque (Macaca nigra) infant, captive.

Suzi Eszterhas / African Elephant (Loxodonta africana) herd drinking at waterhole, Mashatu Game Reserve, Botswana

Suzi Eszterhas / African Elephant (Loxodonta africana) herd drinking at waterhole, Mashatu Game Reserve, Botswana

Suzi Eszterhas / African Elephant (Loxodonta africana) mother and calf at waterhole, Mashatu Game Reserve, Botswana

Suzi Eszterhas / African Elephant (Loxodonta africana) calf drinking at waterhole, Mashatu Game Reserve, Botswana

Suzi Eszterhas / Leopard (Panthera pardus) one-year-old cub in tree, Jao Reserve, Botswana

Suzi Eszterhas / Leopard (Panthera pardus) one-year-old cub, Jao Reserve, Botswana

Suzi Eszterhas / Leopard (Panthera pardus) mother and eight-month-old cub, Jao Reserve, Botswana

Suzi Eszterhas / Leopard (Panthera pardus) four-month-old cub in tree, Jao Reserve, Botswana

Suzi Eszterhas / Leopard (Panthera pardus) four-month-old cub in tree, Jao Reserve, Botswana

Suzi Eszterhas / Leopard (Panthera pardus) mother and four-month-old cubs, Jao Reserve, Botswana

Suzi Eszterhas / Leopard (Panthera pardus) six-week-old cub nursing, Jao Reserve, Botswana

Suzi Eszterhas / Leopard (Panthera pardus) six-week-old cubs playing, Jao Reserve, Botswana

Suzi Eszterhas / Leopard (Panthera pardus) six-week-old cub, Jao Reserve, Botswana

Suzi Eszterhas / Leopard (Panthera pardus) six-week-old cub nuzzling mother, Jao Reserve, Botswana

Suzi Eszterhas / Leopard (Panthera pardus) mother playing with her six-week-old cub, Jao Reserve, Botswana

Suzi Eszterhas / Leopard (Panthera pardus) five-week-old cub, Jao Reserve, Botswana

Suzi Eszterhas / Leopard (Panthera pardus) five-week-old cub, Jao Reserve, Botswana

Suzi Eszterhas / Leopard (Panthera pardus) five-week-old cub playing with mother's tail, Jao Reserve, Botswana

Suzi Eszterhas / Leopard (Panthera pardus) five-week-old cub playing with mother's tail, Jao Reserve, Botswana

Suzi Eszterhas / Leopard (Panthera pardus) mother and five-week-old cub, Jao Reserve, Botswana

Suzi Eszterhas / Leopard (Panthera pardus) mother grooming five-week-old cub, Jao Reserve, Botswana

Suzi Eszterhas / Leopard (Panthera pardus) five-week-old cub playing with mother, Jao Reserve, Botswana

John Chan / Great horned owl (Bubo virginianus) chicks stretching and flapping their wings, Southern California, USA, May.

John Chan / Great horned owl (Bubo virginianus) chick watching for parents to return with food, Southern California, USA, June.

David Woodfall / Dunlin (Calidris alpina) small wader with young in machair. North Uist, Scotland, UK, June.

David Woodfall / Little tern (Sterna albifrons ) feeding sand eel (Hyperoplus spp) to young chick. Gronant Dunes, Denbighshire, Wales, UK, June.

John Shaw / Snow monkey or Japanese macaque (Macaca fuscata) female with baby clinging to her back. Jigokudani, Japan, February.

John Shaw / Common loon (Gavia immer) with a chick alongside. British Columbia, Canada. June.

Andy Rouse / Galapagos sea lion, (Zalophus wollebaeki), pup on shore, Galapagos.

Andy Rouse / RF - African Lion, (Panthera leo), female with cub, Masai Mara, Kenya, Africa,

Jiri Lochman / Brush-tailed phascogale (Phascogale tapoatafa) female with young, Kingston Forest, Western Australia, October.

John Cancalosi / Great horned owl (Bubo virginianus) chick stretching its wings in nest in a Saguaro (Carnegiea gigantea), is groomed by its parent, Sonoran Desert, Arizona, USA, May.

John Chan / Anna's Hummingbird (Calypte anna) chick, sleeping in nest, Southern California, USA, March.

Morley Read / Close-up of an Amazon leaf frog (Cruziohyla Craspedopus) tadpole developing in egg, Ecuador. (non-ex)