Pupils look at an orphaned baby elephant at the David Sheldrick Elephant Orphanage within the Nairobi National Park, near Kenya's capital Nairobi October 15, 2014. The orphanage under the David Sheldrick Wildlife Trust is operated by Daphne Sheldrick, wife of late famous naturalist David William Sheldrick. The orphaned elephants raised by the trust will be returned to join the undomesticated elephant population in Tsavo National Park, where David was the founder warden from 1948 to 1976, when they mature, usually between eight to 10 years old. (Photo by Goran Tomasevic/Reuters)

A one and a half months old baby elephant stands close to its mother at Chitwan National Park in Chitwan, south of Kathmandu December 30, 2014. (Photo by Navesh Chitrakar/Reuters)

Edinburgh Zoo is proud to introduce this baby three-banded armadillo Rica who was born to mum Rio and dad Rodar in Edinburgh, Scotland, UK on Sunday 24 August 2014. A tiny 81g at birth and around the same size as a golf ball, Rica is a female three banded armadillo who has grown rapidly in her first month, already quadrupling in weight. (Photo by SWNS/ABACAPress)

Gorillas at Royal Burgers’ Zoo, Arnhem, Netherlands, on November 28, 2013. (Photo by Vidi Photo/Startraks Photo New York)

A baby hippo swims under the water in its enclosure at Prague Zoo, Czech Republic, February 24, 2016. The baby was born on January 28, and is yet to be named. (Photo by David W. Cerny/Reuters)

Chinese Panda Yang Guang arrives at Edinburgh Airport on December 4, 2011 in Edinburgh, Scotland. Tian Tian and Yang Guang, a pair of eight-year-old giant pandas arrived on a specially chartered flight and will be the first to live in the UK for 17 years. Edinburgh Zoo are hopeful that the pandas will give birth to cubs during their 10 year stay in Scotland. (Photo by Jeff J Mitchell/Getty Images)

Yuan Zi, a male giant panda and Huan Huan, a female giant panda, share their life inside their enclosure at Zoo Parc De Beauval on January 25, 2012 in Beauval, France. A pair of giant pandas which have been loaned to the zoo by China, where they hope the pair will reproduce and help boost the world's dwindling panda population. (Photo by Franck Prevel/Getty Images)