Two brown bear cubs born at Whipsnade Zoo. (Photo by Evening Standard/Getty Images). 1970

Meet the star students of orangutan school – the unique rehab centre where orphaned apes are taught how to climb trees and survive in the wild without their mum and dad. (Photo by Caters News)

A US Marine feeds an orphan kitten found after a heavy mortar barrage near “Bunker Hill” during the Korean War. (Photo by Sgt Martin Riley/Getty Images). 1953

In this September 17, 2010 file photo a little brown bat is photographed in La Crosse Wis. Researchers for the first time found that little brown bats appear to be showing resistance to white-nose syndrome, which has killed millions of bats across North America. (Photo by Peter Thomson/La Crosse Tribune via AP Photo)

A hungry cow smiles for the camera in Salzburg, Austria. One of a series of funny animal mugshots taken by Chanel Cartell and Stevo Dirnberger during their travels around the globe. (Photo by Chanel Cartell/Stevo Dirnberger/Rex Features/Shutterstock)

A spider monkey eats a mango at the Paraguana zoo in Punto Fijo, Venezuela July 22, 2016. Some 50 animals have starved to death in the last six months at one of Venezuela's main zoos due to chronic food shortages that have plagued the crisis-stricken South American nation. (Photo by Carlos Jasso/Reuters)

Gray whale feeding at the surface and showing it's baleen. (Photo by Christopher Swann/Biosphoto)

A gibbon drinks from a soft drink bottle, given by a tourist, at a zoo in Kunming, Yunnan province, June 18, 2015. (Photo by Wong Campion/Reuters)