ZSSD / California Condor (Gymnogyps californianus) spreading wings, native to California

ZSSD / Black Rhinoceros (Diceros bicornis) portrait of calf, native to Africa

Konrad Wothe / Black Rhinoceros (Diceros bicornis) mother and calf crossing savannah, Ngorongoro Crater, Tanzania

Konrad Wothe / Mountain Gorilla (Gorilla gorilla beringei) males fighting, Virunga National Park, Democratic Republic of the Congo

Konrad Wothe / Mountain Gorilla (Gorilla gorilla beringei) baby rolling on forest floor, Virunga National Park, Congo

Mitsuaki Iwago / Black Rhinoceros (Diceros bicornis) portrait, Ngorongoro Crater, Tanzania

Mitsuaki Iwago / Black Rhinoceros (Diceros bicornis) grazing in grassland surrounded by a flock of Cattle Egrets (Bubulcus ibis), Ngorongoro Crater, Tanzania

Mitsuaki Iwago / Black Rhinoceros (Diceros bicornis) with Cattle Egret (Bubulcus ibis) on its back, Ngorongoro Crater, Tanzania

Mitsuaki Iwago / Black Rhinoceros (Diceros bicornis) charging, Serengeti National Park, Tanzania

Mitsuaki Iwago / Black Rhinoceros (Diceros bicornis) mother and baby with Red-billed Oxpeckers (Buphagus erythrorhynchus), Ngorongoro Crater, Tanzania

Gerry Ellis / Black Rhinoceros (Diceros bicornis) portrait, Lewa Wildlife Conservation Area, Kenya

Gerry Ellis / Mountain Gorilla (Gorilla gorilla beringei) female showing finger lost to poacher's trap, Virunga Mountains, Democratic Republic of the Congo

Mike Parry / Leatherback Sea Turtle (Dermochelys coriacea) on land, Huon Gulf, Papua New Guinea, critically endangered

Mike Parry / Southern Bluefin Tuna (Thunnus maccoyii) school underwater, South Australia

Yva Momatiuk & John Eastcott / California Condor (Gymnogyps californianus) immature bird flying with transmitter attached, critically endangered extinct in wild and recently re-introduced, 9-10 foot wingspan, Marble Canyon, Arizona

Mike Parry / Leatherback Sea Turtle (Dermochelys coriacea) underwater view of swimming hatchling, Huon Gulf, Papua New Guinea

Mike Parry / Leatherback Sea Turtle (Dermochelys coriacea) hatchling trio entering sea, Huon Gulf, Papua New Guinea

Mike Parry / Southern Bluefin Tuna (Thunnus maccoyii) underwater, South Australia

Michael & Patricia Fogden / Gharial (Gavialis gangeticus) portrait, India

Claus Meyer / Cotton-top Tamarin (Saguinus oedipus), Colombia

Gerry Ellis / Western Lowland Gorilla (Gorilla gorilla gorilla) male portrait, endangered, native to Africa

Gerry Ellis / Mountain Gorilla (Gorilla gorilla beringei) family resting in rainforest, Virunga, Rwanda

Gerry Ellis / Mountain Gorilla (Gorilla gorilla beringei) male, Virunga Mountains nestled along the northern border of Rwanda, the Democratic Republic of the Congo and Uganda

Konrad Wothe / Western Lowland Gorilla (Gorilla gorilla gorilla) silverback, Africa

Jim Brandenburg / Black Rhinoceros (Diceros bicornis) portrait, South Africa

Gerry Ellis / Western Lowland Gorilla (Gorilla gorilla gorilla) silverback male portrait, Africa

Gerry Ellis / Western Lowland Gorilla (Gorilla gorilla gorilla) silverback male, equatorial Africa

Gerry Ellis / Mountain Gorilla (Gorilla gorilla beringei) group eating, Virunga Mountains

Konrad Wothe / Western Lowland Gorilla (Gorilla gorilla gorilla) male carrying baby, central Africa

Mitsuaki Iwago / Black Rhinoceros (Diceros bicornis) calling in tall grass, Ngorongoro Crater, Tanzania

Tui De Roy / Waved Albatross (Phoebastria irrorata) courtship display sequence, Punta Cevallos, Espanola Island, Galapagos Islands, Ecuador

Tui De Roy / Waved Albatross (Phoebastria irrorata) pair bonding, Punta Cevallos, Espanola Island, Galapagos Islands, Ecuador

Tui De Roy / Waved Albatross (Phoebastria irrorata) pair bonding in flowering tribulus field during rains, Punta Cevallos, Espanola Island, Galapagos Islands, Ecuador

Tui De Roy / Waved Albatross (Phoebastria irrorata) courtship display sequence, Punta Cevallos, Espanola Island, Galapagos Islands, Ecuador

Fred Bavendam / Staghorn Coral (Acropora cervicornis) colony releasing egg-sperm bundles during the mass coral spawning each March at Ningaloo Reef, Western Australia

Norbert Wu / Hawksbill Sea Turtle (Eretmochelys imbricata) underwater, Sipadan Island, Borneo

Jim Brandenburg / Black Rhinoceros (Diceros bicornis) charging, Namibia

Mitsuaki Iwago / Siberian Crane (Grus leucogeranus) pair courting in front of setting sun, China

Tui De Roy / Pinta Island Galapagos Tortoise (Chelonoidis nigra abingdoni), Lonesome George, the last survivor of his race, Darwin Reserve Station, Santa Cruz Island, Galapagos Islands, Ecuador

Flip Nicklin / Hawaiian Monk Seal (Monachus schauinslandi) pair playing, Hawaii

Tui De Roy / Saddleback Galapagos Tortoise (Chelonoidis nigra hoodensis) old male portrait, Pinzon Island, Galapagos Islands, Ecuador

Mitsuaki Iwago / Hawaiian Monk Seal (Monachus schauinslandi) portrait, Hawaii

ZSSD / Sumatran Tiger (Panthera tigris sumatrae) close-up portrait of female, endemic to Sumatra, Indonesia

Fred Bavendam / Hawksbill Sea Turtle (Eretmochelys imbricata) camouflaged against rocks, Coral Sea, Queensland, Australia, critically endangered

Norbert Wu / Coelacanth (Latimeria chalumnae) living fossil, ancestor of amphibians and land vertebrates, Comoros Islands

Flip Nicklin / Vaquita (Phocoena sinus) by-catch casualty, Baja California, Mexico

Fred Bavendam / Staghorn Coral (Acropora cervicornis) colony with an extensive bleached area at its center, Kimbe Bay, Papua New Guinea

Rod Williams / Female Alaotran gentle lemur {Hapalemur griseus alaotrensis} Madagascar. Critically endangered species

Rod Williams / Portrait of Golden lion tamarin {Leontopithecus rosalia} occurs Brazil, Rio de Janeiro State

Rod Williams / Golden lion tamarin {Leontopithecus rosalia} from Brazil, critically endangered species

John Cancalosi / Axolotl / Mexican salamander (Ambystoma mexicanum), white or leucistic form, critically endangered in the wild, captive, native to Mexico

John Cancalosi / Axolotl / Mexican salamander (Ambystoma mexicanum), melanistic form, critically endangered in the wild, captive, native to Mexico

John Cancalosi / Axolotl / Mexican salamander (Ambystoma mexicanum), melanistic form, critically endangered in the wild, captive, native to Mexico

John Cancalosi / Axolotl / Mexican salamander (Ambystoma mexicanum), melanistic form, critically endangered in the wild, captive, native to Mexico

John Cancalosi / Axolotl / Mexican salamander (Ambystoma mexicanum), white or leucistic form, critically endangered in the wild, captive, native to Mexico

John Cancalosi / Axolotl / Mexican salamander (Ambystoma mexicanum), white or leucistic form, critically endangered in the wild, captive, native to Mexico

John Cancalosi / Axolotl / Mexican salamander (Ambystoma mexicanum), white or leucistic form, critically endangered in the wild, captive, native to Mexico

Jabruson / Gula man riding donkey (Equus africanus asinus) carrying water from well, Zakouma National Park, Chad, March 2010

Roland Seitre / Indianapolis zoo worker holding a young Grand Cayman Blue iguana (Cyclura lewisi) from captive breeding program, Indianapolis zoo, Indiana, USA

Roland Seitre / Grand cayman blue iguana (Cyclura lewisi) attacking reflection in mirror, Indianapolis Zoo, Indiana, USA, Endangered species

Roland Seitre / Grand Cayman Blue Iguana (Cyclura lewisi), adult that has been reintroduced to the wild from captive breeding programme. Cayman Islands, Endangered species.

Roland Seitre / Grand Cayman Blue Iguana (Cyclura lewisi) hatchling and egg held in hands, captive, Cayman Islands National Trusts Blue Iguana Recovery Program, Queen Elizebeth Botanic Park, Grand Cayman. Endangered...

Roland Seitre / Grand Cayman Blue Iguana (Cyclura lewisi) captive Cayman Islands National Trusts Blue Iguana Recovery Program, Queen Elizebeth Botanic Park, Grand Cayman

Roland Seitre / Grand Cayman Blue Iguana (Cyclura lewisi) portrait, Cayman Islands, captive, endangered species

Roland Seitre / Cayman blue iguanas (Cyclura lewisi) in captive breeding program, Indianapolis Zoo, Indiana, USA, endangered species

Roland Seitre / Cayman blue iguanas (Cyclura lewisi) attacking its own image in mirror, captive, Indianapolis Zoo, Indiana, USA, Endangered species

Roland Seitre / Cayman blue iguana (Cyclura lewisi) reflected in mirror, captive, Indianapolis Zoo, Indiana, USA, Endangered species

Roland Seitre / Grand Cayman Blue Iguana (Cyclura lewisi) with mouth open defensively, Cayman Islands, captive

Juan Manuel Borrero / Illustration of Mediterranean Monk Seal (Monachus monachus) head and body. Critically Endangered species. Pencil and watercolor painting.

Juan Manuel Borrero / Illustration of threatened species of Spain : Blue whale (Balenoptera musculus), Brown bear (Ursus arctos), Spanish ibex (Capra pyrenaica hispanica), Bullhead (Cottus gobio), Iberian Rock Lizard (Lace...

Ann & Steve Toon / Black rhinoceros (Diceros bicornis) profile portrait, Masai Mara Game reserve, Kenya

Ann & Steve Toon / Black rhinoceros (Diceros bicornis) orphaned calf with security officer John Tanui at Lewa Wildlife Conservancy, Laikipia, Kenya, Africa, September 2012

Ann & Steve Toon / Black rhinoceros (Diceros bicornis) orphaned calf with security officer John Tanui at Lewa Wildlife Conservancy, Laikipia, Kenya, Africa, September 2012

Ann & Steve Toon / Northern white rhino (Ceratotherium simum cottoni) female called Najin, watched over by armed guard, Ol Pejeta Conservancy, Laikipia, Kenya, Africa, September 2012

Ann & Steve Toon / Northern white rhino (Ceratotherium simum cottoni) dehorned male called Sudan, watched over by armed guard, Ol Pejeta Conservancy, Laikipia, Kenya, Africa, September 2012

Ann & Steve Toon / Northern white rhino (Ceratotherium simum cottoni) male called Suni with female Najin, watched over by keepers Jeremy Kimathi and Peter Esogon, Ol Pejeta Conservancy, Laikipia, Kenya, Africa, Septembe...

Ann & Steve Toon / Northern white rhino (Ceratotherium simum cottoni) female called Najin, watched over by armed guard, Ol Pejeta Conservancy, Laikipia, Kenya, Africa, September 2012

Ann & Steve Toon / Northern white rhino (Ceratotherium simum cottoni) female called Najin, Ol Pejeta Conservancy, Laikipia, Kenya, Africa, September 2012

Ann & Steve Toon / Northern white rhino (Ceratotherium simum cottoni) female called Najin, watched over by armed guard, Ol Pejeta Conservancy, Laikipia, Kenya, Africa, September 2012

Ann & Steve Toon / Black rhinoceros (Diceros bicornis) hand-reared blind bull called Baraka based at information centre for community education, Ol Pejeta Conservancy, Laikipia, Kenya, Africa, September 2012 captive

Fiona Rogers / Celebes / Black crested macaque (Macaca nigra) female feeding on leaf shoots, Tangkoko National Park, Sulawesi, Indonesia.

Fiona Rogers / Celebes / Black crested macaque (Macaca nigra) mature male head and shoulders portrait, Tangkoko National Park, Sulawesi, Indonesia.

Fiona Rogers / Celebes / Black crested macaque (Macaca nigra) juvenile head and shoulders portrait, Tangkoko National Park, Sulawesi, Indonesia.

Fiona Rogers / Celebes / Black crested macaque (Macaca nigra) mature male head portrait, Tangkoko National Park, Sulawesi, Indonesia.

Fiona Rogers / Celebes / Black crested macaque (Macaca nigra) sub-adult male head portrait, Tangkoko National Park, Sulawesi, Indonesia.

Fiona Rogers / Celebes / Black crested macaque (Macaca nigra) mature male head portrait, Tangkoko National Park, Sulawesi, Indonesia.

Fiona Rogers / Celebes / Black crested macaque (Macaca nigra) mature male head portrait, Tangkoko National Park, Sulawesi, Indonesia.

Fiona Rogers / Celebes / Black crested macaque (Macaca nigra) mature male head and shoulders sitting portrait, Tangkoko National Park, Sulawesi, Indonesia.

Fiona Rogers / Celebes / Black crested macaque (Macaca nigra) female cradling her baby son aged less than 1 month, Tangkoko National Park, Sulawesi, Indonesia.

Fiona Rogers / Celebes / Black crested macaque (Macaca nigra) 'alpha' baby female aged about 1 month sitting in a tree, Tangkoko National Park, Sulawesi, Indonesia.

Fiona Rogers / Celebes / Black crested macaque (Macaca nigra) female portrait, Tangkoko National Park, Sulawesi, Indonesia.

Fiona Rogers / Celebes / Black crested macaque (Macaca nigra) juvenile feeding on coconut husk, Tangkoko National Park, Sulawesi, Indonesia.

Fiona Rogers / Celebes / Black crested macaque (Macaca nigra) mature male sitting on the forest floor, Tangkoko National Park, Sulawesi, Indonesia.

Fiona Rogers / Celebes / Black crested macaque (Macaca nigra) mature male head portrait, Tangkoko National Park, Sulawesi, Indonesia.

Fiona Rogers / Celebes / Black crested macaque (Macaca nigra) adolescent male feeding on fruit, Tangkoko National Park, Sulawesi, Indonesia.

Fiona Rogers / Celebes / Black crested macaque (Macaca nigra) mature male head and shoulders portrait, Tangkoko National Park, Sulawesi, Indonesia.