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

Kevin Schafer / Darwin's Fox (Pseudalopex fulvipes) portrait, in temperate rainforest, Chiloe Island, Chile, November, Critically Endangered

Kevin Schafer / Golden lion tamarin (Leontopithecus rosalia) wild, Poco das Antas Reserve, Atlantic Forest, Southeast Brazil, Critically endangered, November. Did you know? More than 400 Golden lion tamarins have bee...

Kevin Schafer / Indian gharial (Gavialis gangeticus) Chambal National Sanctuary, Madhya Pradesh, India, Critically Endangered

Kevin Schafer / Darwin's fox (Pseudalopex fulvipes) wild, Chiloe Island, Chile, Critically endangered species, November

Michael D. Kern / Zoo Atlanta / Lemur leaf frog (Hylomantis lemur) captive, Critically endangered, from Central America

Michael D. Kern / Zoo Atlanta / Lemur leaf frog (Hylomantis lemur) mating pair, captive, Critically endangered, from Central America

Lisa Hoffner / Wild Cotton-top tamarin (Saguinus oedipus) appears to fly through the air as it jumps from branch to branch in the dry tropical forest of Colombia, South America. IUCN List: Critically Endangered

Lisa Hoffner / Wild Cotton-top Tamarin (Saguinus Oedipus) on vine, in tropical dry forest of Colombia, South America. IUCN List: Critically Endangered

Lisa Hoffner / Wild Cotton-top tamarins (Saguinus oedipus) climbing up fallen branches in dry tropical forest of Colombia, South America. IUCN List: Critically Endangered

Lisa Hoffner / Wild Cotton-top tamarin (Saguinus oedipus) hanging from hind legs (never before observed behaviour) in the dry tropical forest of Colombia, South America. IUCN List: Critically Endangered

Lisa Hoffner / Portrait of two wild Cotton-top Tamarins (Saguinus Oedipus) resting on vine in tropical dry forest of Colombia, South America. IUCN List: Critically Endangered

Lisa Hoffner / Portrait of wild Cotton-top tamarins (Saguinus oedipus) standing on a branch in dry tropical forest of Colombia, South America IUCN List: Critically Endangered

Mark Carwardine / Northern white rhinoceros (Ceratotherium simum cottoni) with horn removed, after initial release into the wild, Ol Pejeta Conservancy, Kenya, June 2010, Extinct in the wild, only eight left in captivi...

Mark Carwardine / Northern white rhinoceros (Ceratotherium simum cottoni) close-up of eye, Dvur Kralove Zoo, Czech Republic, December 2009, Extinct in the wild, only eight left in captivity, critically endangered, Part...

Mark Carwardine / Northern white rhinoceros (Ceratotherium simum cottoni) close up of eye, in enclosure at Dvur Kralove Zoo, Czech Republic, the day before departure, December 2009, Extinct in the wild, only eight left...

Pete Oxford / Waved albatross (Phoebastria irrorata) in flight with storm clouds, Punto Cevallos, Española (Hood) Island, Galapagos islands, Equador, South America

Suzi Eszterhas / Sumatran Orangutan (Pongo abelii) two and a half year old baby calling, Gunung Leuser National Park, north Sumatra, Indonesia

Suzi Eszterhas / Sumatran Orangutan (Pongo abelii) mother and playful one and a half year old baby, Gunung Leuser National Park, north Sumatra, Indonesia

Suzi Eszterhas / Sumatran Orangutan (Pongo abelii) nine month old baby playing in tree, Gunung Leuser National Park, north Sumatra, Indonesia

Miles Barton / Panamanian Golden Frog (Atelopus ziteki) Panama, Featured in BBC NHU series 'Life in Cold Blood'. Species now extinct in the wild

Miles Barton / Panamanian golden frog (Atelopus ziteki) reacting to the image of a frog on a video monitor. Experiment carried out to reveal the purpose of the frog's waving behaviour - to attract mates and deter ri...

Edwin Giesbers / Portrait of Red ruffed lemur (Varecia variegata ruber) Captive, Netherlands.

Edwin Giesbers / Sclater's black lemur (Eulemur macaco flavifrons) Captive, the Netherlands. Critically Endangered.

Patricio Robles Gil / "Male Baja California / Peninsular pronghorn (Antilocapra americana peninsularis) vocalising, semicaptive breeding facility, Biosphere Reserva of El Vizcano, Baja, Mexico, Critically endangered subspe...

Wild Wonders of Europe / Oxford / Wild Iberian lynx (Lynx pardinus) male, one year, climbing onto rock, Sierra de Andjar Natural Park, Mediterranean woodland of Sierra Morena, north east Jan Province, Andalusia, Spain, April 2009, Cri...

Wild Wonders of Europe / Oxford / Wild Iberian lynx (Lynx pardinus) male carrying rabbit prey, Sierra de Andjar Natural Park, Mediterranean woodland of Sierra Morena, north east Jan Province, Andalusia, Spain, May 2009, Critically end...

Wild Wonders of Europe / Oxford / Wild Iberian lynx (Lynx pardinus) male, Sierra de Andjar Natural Park, Mediterranean woodland of Sierra Morena, north east Jan Province, Andalusia, Spain, April 2009, Critically endangered

Wild Wonders of Europe / Oxford / Wild Iberian lynx (Lynx pardinus) female with juvenile female (one year) Sierra de Andjar Natural Park, Mediterranean woodland of Sierra Morena, north east Jan Province, Andalusia, Spain, April 2009,...

Wild Wonders of Europe / Oxford / Wild Iberian lynx (Lynx pardinus) female walking, Sierra de Andjar Natural Park, Mediterranean woodland of Sierra Morena, north east Jan Province, Andalusia, Spain, April 2009, Critically endangered

Wild Wonders of Europe / Oxford / Wild Iberian lynx (Lynx pardinus) female emerging from undergrowth, Sierra de Andjar Natural Park, Mediterranean woodland of Sierra Morena, north east Jan Province, Andalusia, Spain, April 2009, Criti...

Wild Wonders of Europe / Oxford / Wild Iberian lynx (Lynx pardinus) female, one year, Sierra de Andjar Natural Park, Mediterranean woodland of Sierra Morena, north east Jan Province, Andalusia, Spain, April 2009, Critically endangered

Wild Wonders of Europe / S‡ / Male Monk seal (Monachus monachus) portrait, Deserta Grande, Desertas Islands, Madeira, Portugal, August 2009, Critically endangered species. WWE INDOOR EXHIBITION

Wild Wonders of Europe / Sá / Male Monk seal (Monachus monachus) Deserta Grande, Desertas Islands, Madeira, Portugal, August 2009, Critically endangered species

Wild Wonders of Europe / Sá / Mediterranean Monk seal (Monachus monachus) pair mating, Deserta Grande, Desertas Islands, Madeira, Portugal, August 2009, Critically endangered species

Wild Wonders of Europe / Sá / Mediterranean Monk seal (Monachus monachus) pair mating, Deserta Grande, Desertas Islands, Madeira, Portugal, August 2009, Critically endangered species

Wild Wonders of Europe / Sá / Mediterranean Monk seal (Monachus monachus) pair mating, Deserta Grande, Desertas Islands, Madeira, Portugal, August 2009, Critically endangered species

Wild Wonders of Europe / Sá / Mediterranean Monk seal (Monachus monachus) Deserta Grande, Desertas Islands, Madeira, Portugal, August 2009, Critically endangered species

Wild Wonders of Europe / Sá / Large male Mediterranean Monk seal (Monachus monachus) Deserta Grande, Desertas Islands, Madeira, Portugal, August 2009, Critically endangered species

Wild Wonders of Europe / Sá / Mediterranean Male Monk seal (Monachus monachus) Deserta Grande, Desertas Islands, Madeira, Portugal, August 2009, Critically endangered species

Wild Wonders of Europe / Sá / Female Mediterranean Monk seal (Monachus monachus) Deserta Grande, Desertas Islands, Madeira, Portugal, August 2009, Critically endangered species

Wild Wonders of Europe / Sá / Mediterranean Monk seal (Monachus monachus) juvenile male, Deserta Grande, Desertas Islands, Madeira, Portugal, August 2009, Critically endangered species

Wild Wonders of Europe / Sá / Mediterranean Monk seal (Monachus monachus) pair courting on rocks on seabed, Deserta Grande, Desertas Islands, Madeira, Portugal, August 2009, Critically endangered species

Wild Wonders of Europe / Sá / Mediterranean Monk seal (Monachus monachus) pair mating, Deserta Grande, Desertas Islands, Madeira, Portugal, August 2009, Critically endangered species

Theo Allofs / Celebes Black Macaque (Macaca nigra) pair delousing, Sulawesi, Indonesia

Theo Allofs / Celebes Black Macaque (Macaca nigra) dominant male, Sulawesi, Indonesia

Stephen Dalton / Green mosaic / Rancho grande harlequin frog (Atelopus cruciger) walking along tree trunk, Henri Pittier NP, Venezuela, South America, Critically endangered, thought extinct until a gravid female was f...

Wild Wonders of Europe / Oxford / Wild Iberian lynx (Lynx pardinus) male walking, Sierra de Andjar Natural Park, Mediterranean woodland of Sierra Morena, north east Jan Province, Andalusia, Spain, May 2009, Critically endangered

Wild Wonders of Europe / Oxford / Wild Iberian lynx (Lynx pardinus) male, one year, with GPS tracking collar, sitting, Sierra de Andjar Natural Park, Mediterranean woodland of Sierra Morena, north east Jan Province, Andalusia, Spain,...

Wild Wonders of Europe / Oxford / Wild Iberian lynx (Lynx pardinus) male, Sierra de Andjar Natural Park, Mediterranean woodland of Sierra Morena, north east Jan Province, Andalusia, Spain, May 2009, Critically endangered

Wild Wonders of Europe / Oxford / Wild Iberian lynx (Lynx pardinus) male carrying rabbit prey, Sierra de Andjar Natural Park, Mediterranean woodland of Sierra Morena, north east Jan Province, Andalusia, Spain, May 2009, Critically end...

Wild Wonders of Europe / Oxford / Wild Iberian lynx (Lynx pardinus) female, one year walking, Sierra de Andjar Natural Park, Mediterranean woodland of Sierra Morena, north east Jan Province, Andalusia, Spain, April 2009, Critically en...

Wild Wonders of Europe / Oxford / Wild Iberian lynx (Lynx pardinus) female, one year, on rocks, Sierra de Andjar Natural Park, Mediterranean woodland of Sierra Morena, north east Jan Province, Andalusia, Spain, April 2009, Critically...

Staffan Widstrand / Spoon billed sandpiper (Calidris pygmaea) standing in shallow water, Siberia, Russia, critically endangered

ZSSD / Sumatran Tiger (Panthera tigris sumatrae) cub, native to Sumatra

Chris Newbert / Hawksbill Sea Turtle (Eretmochelys imbricata) and Leather Coral (Sarcophyton sp) on reef, Indonesia

Edwin Giesbers / Black and white ruffed lemur (Varecia variegata variegata) hanging from branch, Madagascar, captive

Pete Oxford / Waved Albatross (Phoebastria irrorata) courtship, Punta Cevallos, Española Island, Galapagos Islands, Critically Endangered

Pete Oxford / Waved Albatross (Phoebastria irrorata) courtship, Punta Cevallos, Espaola Island, Galapagos Islands, Ecuador, South America. Endemic, Critically endangered

Pete Oxford / Waved Albatross (Phoebastria irrorata) courtship, Punta Cevallos, Española Island, Galapagos Islands, Ecuador, South America. Endemic, Critically endangered

Edwin Giesbers / Black and white ruffed lemur (Varecia variegata variegata) portrait, captive, Madagascar

ZSSD / Western Lowland Gorilla (Gorilla gorilla gorilla) scratching its head, native to Africa

Pete Oxford / Waved Albatross (Phoebastria irrorata), Hood Island, Galapagos Islands, Ecuador

Thomas Marent / Red Ruffed Lemur (Varecia rubra) portrait, Masoala National Park, Madagascar

Thomas Marent / Cotton-top Tamarin (Saguinus oedipus) in tree, northern Colombia

Kevin Schafer / Sumatran Tiger (Panthera tigris sumatrae) cub, endangered species native to Sumatra

Kevin Schafer / Leatherback Sea Turtle (Dermochelys coriacea) female laying eggs, Las Baulas National Park, Costa Rica

Kevin Schafer / Darwin's Zorro (Lycalopex fulvipes) a critically endangered fox, Chiloe Island, Chile

Thomas Marent / Mountain Gorilla (Gorilla gorilla beringei) silverback, Volcanoes National Park, Rwanda

Winfried Wisniewski / Black Rhinoceros (Diceros bicornis) running, Tsavo East National Park, Kenya

Premaphotos / Golden mantella frog (Mantella aurantiaca) in rainforest, Madagascar, critically endangered.

ZSSD / Western Lowland Gorilla (Gorilla gorilla gorilla) baby clinging to mother's back, critically endangered, native to Africa

Yva Momatiuk & John Eastcott / California Condor (Gymnogyps californianus) adult with wingspan of 9 feet flying, critically endangered, bred in captivity, later released, and wearing radio transmitter, near Zion National Park, Utah

Ingo Arndt / Mountain Gorilla (Gorilla gorilla beringei) juvenile, Parc National Des Volcans, Rwanda

Ingo Arndt / Mountain Gorilla (Gorilla gorilla beringei) baby, Parc National Des Volcans, Rwanda

Ingo Arndt / Mountain Gorilla (Gorilla gorilla beringei) Susa group showing male silverback, two females and two juveniles, Parc National Des Volcans, Rwanda

Suzi Eszterhas / Mountain Gorilla (Gorilla gorilla beringei) 10 month old infant playfully climbing bamboo pole, endangered, Parc National Des Volcans, Rwanda

Suzi Eszterhas / Mountain Gorilla (Gorilla gorilla beringei) 10 month old infant riding on mother's back, endangered, Parc National Des Volcans, Rwanda

Patricio Robles Gil / Fiji Crested Iguana (Brachylophus vitiensis) beside Heliconia, endemic to Fiji and Tonga

Michael & Patricia Fogden / Costa Rica Brook Frog (Duellmanohyla uranochroa) population numbers have been affected by climate change, Costa Rica

Michael & Patricia Fogden / Harlequin Frog (Atelopus varius) displaying warning coloration, Monteverde, Costa Rica

Pete Oxford / Golden-crowned Sifaka (Propithecus tattersalli) peeking around tree trunk, critically endangered, Daraina, northeast Madagascar

Pete Oxford / Black and White Ruffed Lemur (Varecia variegata variegata) in rainforest near Mantadia National Park, endangered, Madagascar

Pete Oxford / Diademed Sifaka (Propithecus diadema), Mantadia National Park, Madagascar

Tui De Roy / Waved Albatross (Phoebastria irrorata) courtship dance under rainy season clouds, Punta Cevallos, Espanola Island, Galapagos Islands, Ecuador

ZSSD / Panamanian Golden Frog (Atelopus zeteki) pair in amplexus, native to Panama

Pete Oxford / Harpy eagle (Harpia harpyja) female brings large twig to line nest,probably to bury old bones and carcasses. Aguarico river drainage system. Amazon Rainforest, Ecuador. Critically endangered

Michael & Patricia Fogden / Harlequin Frog (Atelopus varius) displaying colorful warning colors, cloud forest, Costa Rica

Mitsuaki Iwago / Black Rhinoceros (Diceros bicornis) with Red-billed Oxpecker (Buphagus erythrorhynchus), Serengeti National Park, Tanzania

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

ZSSD / Western Lowland Gorilla (Gorilla gorilla gorilla) mother walking away with 48 day old baby on back, native to Africa

ZSSD / Western Lowland Gorilla (Gorilla gorilla gorilla) male vocalizing, native to equatorial West Africa

ZSSD / Western Lowland Gorilla (Gorilla gorilla gorilla) male portrait, native to Africa

ZSSD / California Condor (Gymnogyps californianus) portrait, native to California

ZSSD / California Condor (Gymnogyps californianus) portrait, native to California