Sharon Heald / African elephant (Loxodonta africana) charging through water~Etosha National Park, Namibia.

Tony Heald / Leopard (Panthera pardus) young adult, Chobe National Park Botswana.

Tony Heald / Hippopotamus (Hippopotamus Amphibius) territorial aggressive behavior, Chobe National Park, Botswana.

Tony Heald / Elephant (Loxodonta africana) three calves walking down to Chobe River, Etosha National Park, Namibia, March.

Tony Heald / Egyptian goose (Alopochen aegyptiaca) pair amongst Devil's-thorn yellow flowers (Tribulus terrestris)~Etosha National Park, Namibia, March.

Tony Heald / African elephant (Loxodonta africana) South Luangwa NP. Zambia. Digitally enhanced.

Bernard Castelein / Crowned sifaka (Propithecus coronatus), Katsepy, Madagascar

Solvin Zankl / After an incubation period of 45 to 55 days a first hatchling Green turtle (Chelonia mydas) emerges out of the sand, Bonaire, Leeward Antilles, Caribbean region, Netherlands Antilles

Solvin Zankl / Hawksbill sea turtle (Eretmochelys imbricata) Bonaire, Leeward Antilles, Caribbean region, Netherlands Antilles

Solvin Zankl / Green sea turtle (Chelonia mydas) Bonaire, Leeward Antilles, Caribbean region, Netherlands Antilles

Solvin Zankl / Green sea turtle (Chelonia mydas) resting or sleeping on coral reef, Bonaire, Leeward Antilles, Caribbean region, Netherlands Antilles

Solvin Zankl / Southern sea lions (Otaria flavescens) Comau Fjord, Patagonia, Chile, Pacific Ocean, January

Nick Upton / Trooping funnel / Monk's head mushroom (Clitocybe / Infundibulicybe geotropa), group under fallen autumn leaves, LWT Lower Woods reserve, Gloucestershire, UK, October.

Suzi Eszterhas / Proboscis monkey(Nasalis larvatus)Mother and infantSabah, Malaysia

Suzi Eszterhas / Sea otter (Enhydra lutris) mother and pup, aged 3 weeks, Monterey, California, USA.

Suzi Eszterhas / Sea otter (Enhydra lutris) pup sleeping, aged 6 days, floating, Monterey, California, USA.

Suzi Eszterhas / Sea otter (Enhydra lutris) mother and sleeping newborn pup (aged 3 days) Monterey, California, USA.

Suzi Eszterhas / Sea otter (Enhydra lutris) mother and sleeping newborn pup (aged 3 days) Monterey, California, USA. *Digitally darkened scar on mother's nose.

Suzi Eszterhas / Hoffmann's Two-toed sloth (Choloepus hoffmanni) mother and baby, aged 2 months, in tree, Costa Rica. Rescued and released by Aviarios Sloth Sanctuary.

Suzi Eszterhas / Hoffmann's Two-toed sloth (Choloepus hoffmanni) mother and baby, aged 2 months, in tree, Costa Rica. Rescued and released by Aviarios Sloth Sanctuary.

Kim Taylor / Barn owl (Tyto alba) flying in snow covered countryside, Surrey, England, UK, January. Digital composite.

Kim Taylor / Fly (unidentified) head detail. Surrey, England. Digitally enhanced

Edwin Giesbers / Grey wolf (Canis lupus) mother and two month old cubs, pups begging for food by licking mother's mouth, captive

Edwin Giesbers / Harpy eagle (Harpia harpyja) close up head portrait, captive

Edwin Giesbers / Siberian crane (Grus leucogeranus) critically endangered, captive

Edwin Giesbers / Hooded crane (Grus monacha) flapping wings, captive

Edwin Giesbers / Madagascar crested wood ibis (Lophotibis cristata) preening, endemic to dry forest of Madagascar, captive

Edwin Giesbers / Jaguar (Panthera onca) female portrait, native to Southern and Central America, captive

Edwin Giesbers / Jaguar (Panthera onca) female snarling, native to Southern and Central America, captive

Edwin Giesbers / Jaguar (Panthera onca) mother grooming four month cub, native to Southern and Central America, captive

Edwin Giesbers / Jaguar (Panthera onca) female yawning, native to Southern and Central America, captive

Edwin Giesbers / Jaguar (Panthera onca) male and female four month old cubs playing, native to Southern and Central America, captive

Eric Baccega / Whale headed / Shoebill (Balaeniceps rex) portrait. Swamps of Mabamba, Lake Victoria, Uganda.

Eric Baccega / Whale headed / Shoebill (Balaeniceps rex) vocalising. Swamps of Mabamba, Lake Victoria, Uganda.

Eric Baccega / Shoebill stork (Balaeniceps rex) in the swamps of Mabamba, Lake Victoria, Uganda

Eric Baccega / Shoebill stork (Balaeniceps rex) feeding on a Spotted African lungfish (Protopterus dolloi) in the swamps of Mabamba, lake Victoria, Uganda

Luke Massey / Smooth coated otter (Lutrogale perspicillate) jumping into water, Singapore. November.

Luke Massey / Cyclists watching urban Smooth coated otters (Lutrogale perspicillate) cross their path, Singapore. November.

Luke Massey / Smooth coated otter (Lutrogale perspicillate) in urban environment, Singapore. November.

Luke Massey / Smooth coated otter (Lutrogale perspicillate) playing with football net, Singapore. November.

Luke Massey / Smooth coated otter (Lutrogale perspicillate) feeding, Singapore. November.

Luke Massey / Smooth coated otter (Lutrogale perspicillate) in drainage channel, Singapore. November.

Luke Massey / Smooth coated otters (Lutrogale perspicillate) fighting, Singapore. November.

Luke Massey / Przewalski's horses (Equus ferus przewalskii) herd, Chernobyl Exclusion Zone, Ukraine September

Luke Massey / Proboscis monkey (Nasalis larvatus) juveniles playing, Tarakan, Indonesia

Luke Massey / Female peregrine falcon (Falco peregrinus) returns to balcony nest site, Chicago, USA, June 2015,

Luke Massey / Peregrine falcon (Falco peregrinus) returns to nest in balcony, Chicago, USA

Luke Massey / Peregrine falcon (Falco peregrinus) female feeding chicks at nest in balcony, Chicago, USA

Luke Massey / Peregrine falcon (Falco peregrinus) feeding chicks at nest with male flying by, Chicago, USA

Luke Massey / Peregrine falcon (Falco peregrinus) female, on balcony. Chicago, USA, May 2015.

Luke Massey / Peregrine falcon (Falco peregrinus) female peering round wall from nesting site on balcony, Chicago, USA, May 2015.

Luke Massey / Peregrine falcon (Falco peregrinus) feeding chicks at nest in planter on urban balcony, Chicago, USA

Luke Massey / Iberian lynx (Lynx pardinus) portrait, Sierra Morena, Spain October.

Luke Massey / Iberian lynx (Lynx pardinus) portrait, Sierra Morena, Spain October.

Luke Massey / Griffon vulture (Gyps fulvus) portrait of two, Tremp, Spain October.

Luke Massey / Demoiselle cranes (Grus virgo) flock at feeding site in Khichan, India

Luke Massey / Lilian's lovebirds (Agapornis lilianae) bathing in South Luangwa NP, Zambia

Anup Shah / Eastern chimpanzees (Pan troglodytes schweinfurtheii) walking in line close to the shore of Lake Tanganyika. Gombe National Park, Tanzania.

Anup Shah / Eastern chimpanzee (Pan troglodytes schweinfurtheii) Alpha male 'Ferdinand' aged 20 years portrait. Gombe National Park, Tanzania.

Anup Shah / Eastern chimpanzee (Pan troglodytes schweinfurtheii) male 'Faustino' aged 23 years leaving Alpha male 'Ferdinand' aged 20 years and 'Apollo' aged 33 years watching. Gombe National Park, Tanzania.

Franco Banfi / Freshwater isopod, Amphipod gammarus (Acanthogammarus victorii) swimming, Lake Baikal, Siberia, Russia

Franco Banfi / Freshwater isopods (Acanthogammarus victorii) feeding on seabed, Lake Baikal, Siberia, Russia.

Franco Banfi / Young Stone sculpin (Paracottus knerii), on endemic sponge (Lubomirskia baicalensis), Lake Baikal, Siberia, Russia.

Mike Read / Undine Falls Gardiner river, The Grand Loop Road, Yellowstone National Park, Wyoming, USA, June 2015.

Melvin Grey / Turkey vulture (Cathartes aura) captive, occurs in North America.

Andrew Walmsley / Javan slow loris (Nycticebus javanicus), Juvenile temporarily captive to allow measurements to be made. Cipaganti, Garut, Java, Indonesia.

Andrew Walmsley / Javan slow loris (Nycticebus javanicus), Juvenile temporarily captive to allow measurements to be made. Cipaganti, Garut, Java, Indonesia.

Andrew Walmsley / Javan slow loris (Nycticebus javanicus), foraging in the canopy. Cipaganti, Garut, Java, Indonesia.

Javier Aznar / Pebas stubfoot toad (Atelopus spumarius) infected with chytrid fungus, seen through leaf, Ecuador. Overall winner of the Nature Images Awards 2016.

Javier Aznar / Glass frog (Centrolenidae) tadpoles dropping off leaf, Mindo, Ecuador

Christophe Courteau / Crab eating macaque (Macaca fascicularis) group stealing food from tourist bungalow by climbing in through the window. Bako National Park. Sarawak State. Borneo. Malaysia.

Christophe Courteau / Crab eating macaque (Macaca fascicularis) group stealing food from tourist bungalow by climbing in through the window. Bako National Park. Sarawak State. Borneo. Malaysia.

Christophe Courteau / Crab eating macaque (Macaca fascicularis) stealing food from tourist bungalow by climbing in through the window, Bako National Park. Sarawak State. Borneo. Malaysia.

Christophe Courteau / Crab eating macaque (Macaca fascicularis) group stealing food from tourist bungalow by climbing in through the window. Bako National Park. Sarawak State. Borneo. Malaysia.

Nayan Khanolkar / Leopard (Panthera pardus fusca) at night with lights of Mumbai behind, India. January 2016

Nayan Khanolkar / Leopard (Panthera pardus fusca) walking in alley between houses. Aarey Milk Colony in unofficial buffer zone of Sanjay Gandhi National Park, Mumbai, India. January 2016. Winner of Urban category, Wild...

Nayan Khanolkar / Leopard (Panthera pardus fusca) walking in alley between houses. Aarey Milk Colony in unofficial buffer zone of Sanjay Gandhi National Park, Mumbai, India. January 2016. Winner of the Mammals Categor...

Alex Mustard / Hawksbill turtle (Eretmochelys imbricata) cruising along the drop off of a coral reef. Bloody Bay Wall, Little Cayman, Cayman Islands. British West Indies. Caribbean Sea. Note that this turtle has two...