Bernard Castelein / Silky sifaka (Propithecus candidus) in tree, Marojejy National Park, Madagascar. Critically endagered species.

Heather Angel / Northern white cheeked gibbon (Nomascus leucogenys) female standing in tree with baby aged two weeks. Parents captive bred and released. Wild Elephant Valley / Xishuangbanna, Yunnan Province, China, 2...

Lorraine Bennery / Blue-eyed lemur (Eulemur flavifrons) female in tree. Sahamalaza, Madagascar.

Enrique Lopez-Tapia / Tourists riding Bactrian camels (Camelus bactrianus) in sand dunes, Nubra Valley. Ladakh, India, September 2018.

Enrique Lopez-Tapia / Man leading Bactrian camels (Camelus bactrianus) in sand dunes, Nubra Valley. Ladakh,,India, September 2018.

Shane Gross / Cuban crocodile (Crocodylus rhombifer) in a cenote in Cienaga de Zapata National Park. Cuba. Critically endangered species.

Magnus Lundgren / Wild Wonders of China / Central Yunnan black crested gibbon (Nomascus concolor jingdongensis), mother and baby hanging in canopy. Wuliangshan Nature Reserve, Jingdong, Yunnan Province, China.

Tui De Roy / Waved albatross (Phoebastria irrorata) pair in courtship display at nest site, Punta Suarez, Espanola Island, Galapagos

Edwin Giesbers / Blue-eyed / Sclater's black lemur (Eulemur flavifrons) male with arm on female's back, captive, endemic to Madagascar., Critically Endangered.

Roland Seitre / Black rhinoceroses (Diceros bicornis) swimming acorss river, Zimbabwe.

Alex Mustard / Hawksbill turtle (Eretmochelys imbricata) swimming at night. East End, Grand Cayman, Cayman Islands. Caribbean Sea.

Alex Mustard / Hawksbill turtle (Eretmochelys imbricata) cruising along the drop off of a coral reef. Bloody Bay Wall, Little Cayman, Cayman Islands. Caribbean Sea. NB. Turtle has two identification tags in its fron...