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

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

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

Suzi Eszterhas / Cotton-top tamarin (Saguinus oedipus), adult with two week old baby on back. Northern Colombia.

Suzi Eszterhas / Red-shanked douc langur (Pygathrix nemaeus) infant sucking thumb while caretaker holds it. Animal was rescued from illegal wildlife trade, Endangered Primate Rescue Center, Cuc Phuong National Park, V...

Willi Rolfes/ BIA / Alpine Marmot (Marmota marmota) parent with young feeding, Hohe Tauern National Park, Austria

Marion Vollborn/ BIA / Leopard (Panthera pardus) cub, Okavango Delta, Botswana

Willi Rolfes/ BIA / Alpine Marmot (Marmota marmota) parent feeding with begging young, Hohe Tauern National Park, Austria

Willi Rolfes/ BIA / Alpine Marmot (Marmota marmota) parent with young feeding, Hohe Tauern National Park, Austria

Cyril Ruoso / Ring-tailed Lemur (Lemur catta) mother with young drinking, Anja Park, Madagascar

Richard Du Toit / Northern Giraffe (Giraffa camelopardalis) calves, iSimangaliso Wetland Park, KwaZulu-Natal, South Africa

Flip Nicklin / Humpback Whale (Megaptera novaeangliae) calf, Maui, Hawaii

Flip Nicklin / Humpback Whale (Megaptera novaeangliae) mother and calf, Maui, Hawaii

Flip Nicklin / Humpback Whale (Megaptera novaeangliae) calf, Maui, Hawaii

Paul Souders/ Worldfoto / African Elephant (Loxodonta africana) calf feeding, Ngorongoro Conservation Area, Tanzania

Donald M. Jones / White-tailed Deer (Odocoileus virginianus) mother cleaning fawn, Montana

Donald M. Jones / White-tailed Deer (Odocoileus virginianus) doe cleaning newborn fawn, Montana

Donald M. Jones / White-tailed Deer (Odocoileus virginianus) doe smelling newborn fawn, Montana

Agustin Esmoris / American Oystercatcher (Haematopus palliatus) parent with chick, Chubut, Argentina

Christophe Courteau / Mountain gorilla (Gorilla beringei beringei) female with baby, portrait. Volcanoes National Park, Rwanda.

Chase Dekker / Red Fox (Vulpes vulpes) kit, Washington

Marion Vollborn/ BIA / Cheetah (Acinonyx jubatus) cub, Castile-La Mancha, Spain

Hiroya Minakuchi / African Elephant (Loxodonta africana) mothers and calves, Amboseli National Park, Kenya

Hiroya Minakuchi / African Elephant (Loxodonta africana) herd, Amboseli National Park, Kenya

Richard Du Toit / Northern Giraffe (Giraffa camelopardalis) mother and calf, Itala Game Reserve, KwaZulu-Natal, South Africa

Juergen & Christine Sohns / Swamp Wallaby (Wallabia bicolor) mother and joey, Mount Lofty, South Australia, Australia

Juergen & Christine Sohns / Eastern Grey Kangaroo (Macropus giganteus) mother with joey, Maloney Beach, New South Wales, Australia

Juergen & Christine Sohns / Eastern Grey Kangaroo (Macropus giganteus) mother with joey jumping, Maloney Beach, New South Wales, Australia

Juergen & Christine Sohns / African Elephant (Loxodonta africana) calf, Addo National Park, South Africa

Suzi Eszterhas / Mallard (Anas platyrhynchos) rehabilitator, Isabel Luevano, with one day old orphan duckling, International Bird Rescue, Fairfield, California

Michael Quinton / Northern Hawk Owl (Surnia ulula) parent with chicks at nest, Alaska

Andrew Peacock / White Rhinoceros (Ceratotherium simum) mother and calf in grassland, Ol Pejeta Conservancy, Kenya

Juergen & Christine Sohns / African Elephant (Loxodonta africana) calf, Addo National Park, South Africa

Juergen & Christine Sohns / African Elephant (Loxodonta africana) calf drinking at waterhole, Addo National Park, South Africa

Juergen & Christine Sohns / African Elephant (Loxodonta africana) mother browsing with calves, Addo National Park, South Africa

Juergen & Christine Sohns / African Elephant (Loxodonta africana) mother and calf, Addo National Park, South Africa

Juergen & Christine Sohns / African Elephant (Loxodonta africana) mother and calf, Addo National Park, South Africa

Sebastian Kennerknecht / Harbor Seal (Phoca vitulina) pup, Elkhorn Slough, Monterey Bay, California

Sebastian Kennerknecht / Harbor Seal (Phoca vitulina) pup, Elkhorn Slough, Monterey Bay, California

Fiona Rogers / Eastern chimpanzee (Pan troglodytes schweinfurtheii) infant male 'Fifty' aged 3 years portrait.Gombe National Park, Tanzania.

Yva Momatiuk & John Eastcott / Mustang (Equus caballus) mother and foal, Oshoto, Wyoming

Yva Momatiuk & John Eastcott / Mustang (Equus caballus) mother and foal, Oshoto, Wyoming

Anup Shah / Eastern Chimpanzee (Pan troglodytes schweinfurthii) sixteen month old baby female, named Gossamer, in tree, Gombe National Park, Tanzania

Fiona Rogers / Eastern Chimpanzee (Pan troglodytes schweinfurthii) five year old juvenile female, named Fadhila, playing with her three year old brother, named Fifty, Gombe National Park, Tanzania

Chien Lee / Pygmy Anteater (Cyclopes didactylus) mother and young, Esmeraldas, Ecuador

Chien Lee / Giant Crab Spider (Sparassidae) feeding on young Peacock Day Gecko (Phelsuma quadriocellata), Madagascar

Chien Lee / Spike-browed Frog (Sphenophryne cornuta) father transporting froglets, Digul River, West Papua, Indonesia

Chien Lee / Spike-browed Frog (Sphenophryne cornuta) father transporting froglets, Digul River, West Papua, Indonesia

Jaymi Heimbuch / African Elephant (Loxodonta africana) orphaned calves with keeper, David Sheldrick Wildlife Trust, Nairobi, Kenya

Jaymi Heimbuch / African Elephant (Loxodonta africana) orphaned calf bottle fed by keeper, David Sheldrick Wildlife Trust, Nairobi, Kenya

Mark Raycroft / German Shepherd (Canis familiaris) puppies, North America

Mark Raycroft / Golden Retriever (Canis familiaris) puppy, North America

Mark Raycroft / Cocker Spaniel (Canis familiaris) puppy playing, North America

Marion Vollborn/ BIA / African Lion (Panthera leo) cubs drinking at waterhole, Okavango Delta, Botswana

Donald M. Jones / Black Bear (Ursus americanus) cub in tree, western Canada

Marion Vollborn/ BIA / Cheetah (Acinonyx jubatus) cub, native to Africa

Alfred Trunk/ BIA / Common Merganser (Mergus merganser) mother carrying chick, Upper Austria, Austria

Christof Wermter/ BIA / Demoiselle Crane (Anthropoides virgo) parent with chick, Germany

Graeme Guy/ BIA / Eastern Osprey (Pandion cristatus) parent feeding chick in nest, Western Australia, Australia