Andy Murch / Spiny dogfish (Squalus acanthias) portrait. Rhode Island, New England, USA. August.

Jeff Foott / California condor (Gymnogyps californianus) landing, forest in background. Bird with tags on wings. Near San Pedro Martir National Park, Northern Baja California, Mexico. 2017.

Robert Thompson / Crested gecko (Correlophus ciliatus), New Caledonia, controlled conditions

Suzi Eszterhas / Northern muriqui monkey (Brachyteles hypoxanthus) juvenile aged one year, in tree playing with its mother's tail, RPPN Feliciano Miguel Abdala, Atlantic Forest, Brazil. June.

Nick Hawkins / Central American spider monkey (Ateles geoffroyi) juvenile, Corcovado National Park, Costa Rica. January.

Claudio Contreras / California condor (Gymnogyps californianus), portrait. California condor recovery program, Sierra de San Pedro Martir National Park, Baja California Peninsula, Mexico.

Claudio Contreras / California condor (Gymnogyps californianus), two peched in tree, adult and juvenile. California condor recovery program, Sierra de San Pedro Martir National Park, Baja California Peninsula, Mexico.

Jack Dykinga / Bald eagle (Haliaeetus leucocephalus) perched as Snow geese (Chen caerulescens) fly by, Bosque del Apache National Wildlife Refuge, New Mexico, USA, January.

Jack Dykinga / Sandhill cranes (Antigone canadensis) and Snow geese (Chen caerulescens) at sunrise, Bosque del Apache National Wildlife Refuge, New Mexico, USA, November.

Alex Mustard / RF - Green sea turtle (Chelonia mydas) Misool, Raja Ampat, West Papua, Indonesia. Ceram Sea. Tropical West Pacific Ocean. (This image may be licensed either as rights managed or royalty free.)

Alex Mustard / Coral (Lobophytum sp.) on a reef flat, with Hawksbill turtle (Eretmochelys imbricata) in background. Misool, Raja Ampat, West Papua, Indonesia. Ceram Sea. Tropical West Pacific Ocean.

Alex Mustard / Hawksbill turtle (Eretmochelys imbricata) unusually feeding on hard coral polyps. Misool, Raja Ampat, West Papua, Indonesia. Ceram Sea. Tropical West Pacific Ocean.

Alex Mustard / Green turtle (Chelonia mydas) descending after breathing at the surface. Misool, Raja Ampat, West Papua, Indonesia. Ceram Sea. Tropical West Pacific Ocean.

Alex Mustard / Blacktip reef shark (Carcharhinus melanopterus) swims through schools of fish. Misool, Raja Ampat, West Papua, Indonesia. Ceram Sea. Tropical West Pacific Ocean.

Alex Mustard / Three Pink anemonefish (Amphiprion perideraion) living in a purple skirted magnificent sea anemone (Heteractis magnifica) on a coral reef, below a small island. Misool, Raja Ampat, West Papua, Indones...

Jack Dykinga / Yellow-headed blackbirds (Xanthocephalus xanthocephalus) and Redwing blackbirds (Agelaius phoeniceus) roosting. Whitewater Draw Wildlife Area, Arizona, USA, December.

Jack Dykinga / Murmuration of Yellow-headed blackbirds (Xanthocephalus xanthocephalus) and Redwing blackbirds (Agelaius phoeniceus) at sunset, before roosting. Whitewater Draw Wildlife Area, Arizona, USA, December.

John Shaw / Black-browed albatross pair (Thalassarche melanophris) mutual grooming during copulation. New Island, Falkland Islands, November.

Claudio Contreras / Central American spider monkey (Ateles geoffroyi) juveniles hanging by tails and playing, Calakmul Biosphere Reserve, Yucatan Peninsula, Mexico, August

Suzi Eszterhas / Cotton-top tamarin (Saguinus oedipus), three climbing tree. Northern Colombia.

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

Jeff Foott / Yacare caiman (Caiman yacare) with butterfly on snout, Cuiaba River, Pantanal Matogrossense National Park, Pantanal, Brazil.

Jeff Foott / Wild California condor (Gymnogyps californianus) near San Pedro Martir National Park, Northern Baja California, Mexico.

Andy Trowbridge / Kea (Nestor notabilis) juvenile in flight. Arthur's Pass National Park, South Island, New Zealand. Endangered Species.

Richard Robinson / False killer whales (Pseudorca crassidens) travelling with a pod of pelagic Bottlenose dolphins (Tursiops truncatus) Northern New Zealand Editorial use only.

Richard Robinson / False killer whales (Pseudorca crassidens) travelling with a pod of pelagic Bottlenose dolphins (Tursiops truncatus) Northern New Zealand Editorial use only.

Staffan Widstrand / Western crowned pigeon, (Goura cristata), Aiduma Island, Triton Bay, near mainland New Guinea, Western Papua, Indonesian New Guinea

Staffan Widstrand / Western crowned pigeon, (Goura cristata), Aiduma Island, Triton Bay, near mainland New Guinea, Western Papua, Indonesian New Guinea

Richard Robinson / Snares crested penguin (Eudyptes robustus) on rock washed with sea surf, Snares (Tine Heke) Sub Antarctic Island Group, Southern Ocean, New Zealand. December 2016. Editorial use only.

Jabruson Motion / Close-up of a female Mountain gorilla (Gorilla beringei beringei) feeding, gets up and rolls into new resting position near other family members, Bukima, Virunga National Park, Democratic Republic of...

Jabruson Motion / Female Mountain gorilla (Gorilla beringei beringei) getting up from resting and eating, twirls around before settling down into a new resting position, Bukima, Virunga National Park, Democratic Republ...

Gerrit Vyn / Mature male California Condor (Gymnogyps californianus) used for the captive breeding program to restore this critically endangered species. Idaho. February.

Richard Robinson / Shortfin mako shark (Isurus oxyrinchus) head on just below surface, another in background, off the West Coast of Auckland, New Zealand, February

Carol Walker / Wild pinto Mustang mare and foal running in Sand Wash Basin, Colorado, USA.

Pete Oxford / Whale Shark (Rhincodon typus) with scuba diver, Cenderawasih Bay, West Papua, Indonesia.

Pete Oxford / Whale Shark (Rhincodon typus) close up of spotted skin, with Golden trevally (Gnathanodon speciosus) Cenderawasih Bay, West Papua, Indonesia.

Fred Olivier / Southern rockhopper penguin (Eudyptes chrysocome) at nest in breeding colony, stretching and knocking chick over, New Island, Falkland Islands.

Fred Olivier / Tilt shot of a Black browed albatross (Thalassarche melanophris) with its chick on a nest, New Island, Falkland Islands.

Fred Olivier / Southern rockhopper penguin (Eudyptes chrysocome) preening chick then itself, New Island, Falkland Islands.

Fred Olivier / Close-up of a pair of Black browed albatrosses (Thalassarche melanophris) mutual grooming, New Island, Falkland Islands.

Fred Olivier / Black browed albatross (Thalassarche melanophris) chick in nest, interacting with a Southern rockhopper penguin (Eudyptes chrysocome) chick, New Island, Falkland Islands.

Fred Olivier / Pair of Black browed albatrosses (Thalassarche melanophris) display bonding, touching beaks, New Island, Falkland Islands.

Bence Mate / Montezuma oropendolas (Psarocolius montezuma) perched either side of Brown-hooded parrot (Pyrilia haematotis) in rain, Laguna del Lagarto, Santa Rita, Costa Rica

Bence Mate / Black vulture (Coragyps atratus) face to face with King vulture (Sarcoramphus papa) Costa Rica.

Bence Mate / Black vulture (Coragyps atratus) squabbling with King vulture (Sarcoramphus papa) Costa Rica.

Edwin Giesbers / Brown headed spider monkey (Ateles fusciceps) mother and baby, captive occurs in Central and South America.

Edwin Giesbers / Brown headed spider monkey (Ateles fusciceps) group resting together, captive occurs in Central and South America.

Edwin Giesbers / Golden lion tamarin (Leontopithecus rosalia) captive, occurs in the Atlantic Rainforest of Brazil. Critically endangered.