Edwin Giesbers / Female Orang Utan (Pongo pygmaeus) sitting, holding two young. One is her own offspring, the other was rejected by its birth mother, and so this female has adopted it. Both young are 3 months old.Capt...

Duncan Usher / Wild Boar (Sus scrofa) sow with piglets in snow, Sababurg, Hessen, Germany

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

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.

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

Marie Read / Common loons (Gavia immer), two adults and chick swimming on a misty lake in early morning, Michigan, USA. June.

TJ Rich / Four chocolate working cocker spaniels on wall. Mother and offspring. Monmouth, Monmouthshire, Wales

Edwin Giesbers / Close-up of a litter of Wild boar (Sus scrofa) piglets sleeping on top of their mother, with another piglet joining, Germany, January. Captive.

Edwin Giesbers / Close-up of a litter of Wild boar (Sus scrofa) piglets sleeping on top of their mother, with another piglet joining, Germany, January. Captive.

Edwin Giesbers / Close-up of a litter of Wild boar (Sus scrofa) piglets sleeping on top of their mother, Germany, January. Captive.

Marie Read / Eared grebes (Podiceps nigricollis), pair, one adult feeding one of two chicks riding on the other adult's back, Bowdoin National Wildlife Refuge, Montana, USA

Marie Read / Eared grebes (Podiceps nigricollis), pair, one adult carrying food (damselfly) for two chicks riding on the other adult's back, Bowdoin National Wildlife Refuge, Montana, USA

Marie Read / Eared grebes (Podiceps nigricollis), pair, one adult feeding chick riding on the other adult's back, Bowdoin National Wildlife Refuge, Montana, USA

Jabruson Motion / Female Sumatran orangutan (Pongo abelii) 'Wati' feeding on ants, with a juvenile wanting to join in, Bukit Lawang Orangutan Sanctuary, Gunung Leuser National Park, North Sumatra, Indonesia.

Jabruson Motion / Female Sumatran orangutan (Pongo abelii) 'Wati' feeding on ants with a juvenile, Bukit Lawang Orangutan Sanctuary, Gunung Leuser National Park, North Sumatra, Indonesia.

Brian Bevan / Grey seal (Halichoerus grypus) pup trying to suckle, Norfolk, England, UK, January.

Fred Olivier / Young Burchell's zebra (Equus burchellii) playing, biting and kicking its mother, Serengeti NP, Tanzania.

Andy Rouse / Bengal tiger (Panthera tigris tigris) female 'T19 Krishna' carrying 2 month cub, Ranthambhore National Park, India.

David Pattyn / Little Grebe (Tachybaptus ruficollis) female sleeping with one of her 28 day chicks. The Netherlands, June.

Enrique López-Tapia de Inés / Rita Pudel, widow, with her son, in the room that serves as a shelter, in Namaskar Association ‘House of Widows’. Culturally in Nepal women lose many rights when they become widows and may be treated...

Bertie Gregory / 2020VISION / Adult male Peregrine falcon (Falco peregrinus) food passing a Feral pigeon (Columba livia) to his offspring, Bristol, England, UK, June.

Rob Jordan / 2020VISION / Merlin (Falco columbarius) female on perch with Meadow Pipit chick prey for its offspring. Sutherland, Scotland, UK, June. 2020VISION Book Plate.

Rob Jordan / 2020VISION / Merlin (Falco columbarius) female on perch with Meadow Pipit chick prey for its offspring. Sutherland, Scotland, June.

Rob Jordan / 2020VISION / Merlin (Falco columbarius) female on perch with Meadow Pipit chick prey for its offspring. Sutherland, Scotland, June.

Rob Jordan / 2020VISION / Merlin (Falco columbarius) female on perch with Meadow Pipit chick prey, legs just visible, for its offspring. Sutherland, Scotland, June.

Bernard Castelein / Zanzibar Red Colobus (Procolobus kirkii) mother with offspring, sitting in tree, Jozani Chwaka Bay NP, Zanzibar, Tanzania

Suzi Eszterhas / Sumatran Orangutan (Pongo abelii) female grabbing the hand of her offspring, aged 1.5 years, North Sumatra, Indonesia. Critically Endangered

Martin Dohrn / Sleeping African elephants (Loxodonta africana), two adults and offspring, Masai Mara, Kenya. Image taken at night using thermal camera technology without artificial light.

Ann & Steve Toon / Roan antelope (Hippotragus equinus) with young offspring, Mlilwane nature reserve breeding programme, Swaziland, Southern Africa

Ann & Steve Toon / Roan antelope (Hippotragus equinus) with young offspring, Mlilwane nature reserve breeding programme, Swaziland, Southern Africa

Anup Shah / Female Chimpanzee 'Patti' (39-years-old) carries jockey-riding offspring 'Tarzan' on her back {Pan troglodytes schweinfurtheii}, Kasekela community, Gombe NP, Tanzania. 2002

Anup Shah / Female Chimpanzee 'Gremlin' demonstrates to offspring how to use a stem as a tool to remove termites from a termite mound {Pan troglodytes schweinfurtheii} Kasekela community, Gombe NP, Tanzania. 2002

Anup Shah / Female Chimpanzee 'Fanni' with offspring 'Fundi' (male, 17-months-old) and Fudge (male, 4-years-10-months-old) {Pan troglodytes schweinfurtheii}, Kasekela community, Gombe NP, Tanzania. 2002

Juan Manuel Borrero / Mule - offspring of male donkey and female horse - Spain

Pete Oxford / Emperor Penguin (Aptenodytes forsteri) parents with chick. Weddell Sea, Antarctica.

Ingo Arndt / European River Otter (Lutra lutra) sisters resting, Europe

Ingo Arndt / European River Otter (Lutra lutra) sisters resting, Europe

Suzi Eszterhas / Black Bear (Ursus americanus) 7 week old cubs playing in den. One cub shows brown color phase while the other shows black color phase

Suzi Eszterhas / Cheetah (Acinonyx jubatus) mother and eight week old cubs, Maasai Mara Reserve, Kenya

Suzi Eszterhas / African Lion (Panthera leo) four to five week old cubs, vulnerable, Masai Mara National Reserve, Kenya

Donald M. Jones / Red Fox (Vulpes vulpes) kits, Montana