A lioness drinks after being fed by senior keeper Glynn Hennessy at ZSL London Zoo on August 10, 2016 in London, England. Today marks World Lion Day which highlights the first global campaign to celebrate the importance and plight of lions worldwide. (Photo by Carl Court/Getty Images)

Budgies feed on seeds from a local visitor's hands at Ocean Park in metro Manila, Philippines September 10, 2016. (Photo by Romeo Ranoco/Reuters)

Two sheep fight in a competition in Zhangjiakou, Hebei province, China on August 1, 2017. (Photo by Reuters/China Stringer Network)

A baby Sumatran orangutan is bathed after arriving at a wildlife center at Ratchaburi province in Thailand September 13, 2017. (Photo by Kerek Wongsa/Reuters)

19 giant panda cubs, all born this year, meet the public at the Shenshuping Base of the China Conservation and Research Centre for the Giant Panda on October 13, 2017 in Ngawa Tibetan and Qiang Autonomous Prefecture, China. So far China Conservation and Research Centre for the Giant Panda has successfully bred 42 giant pandas this year. (Photo by VCG/VCG via Getty Images)

An undated handout picture released on January 10, 2017 by the Issekinicho publishing house shows an inter- species sexual behaviour between a male Japanese macaque and female sika deer, in Yakushima Scientists revealed on January 10, 2017 the “highly unusual” behaviour of a male monkey filmed trying to have sеx with female deer in Japan – a rare case of inter- species nookie. (Photo by Editions Issekinicho/AFP Photo)

Iberian lynx Mistral jumps in a field after being released by Portugal's Minister of Environment Joao Matos Fernandes (unseen) and others in the Mount Milhouro (Herdade da Cela) region in Mertola, Portugal, 13 May 2016. Mistralis the 18th lynx bred in captivity released since late 2014. (Photo by Nuno Veiga/EPA)

This undated handout photograph released by Stony Brook University/ Louisiana State University on March 2, 2018, shows an Adélie penguin looking at a drone at breeding colony on Heroina Island, Danger Islands, Antarctica. A thriving “hotspot” of some 1.5 million Adelie penguins has been discovered on the remote Danger Islands in the east Antarctic, surprised scientists announced on March 2, 2018. (Photo by Rachael Herman/AFP Photo/Louisiana State University AND Stony Brook University)