A donkey savors warming temperatures after a long winter at the zoo in Warsaw, Poland, on Wednesday, April 8, 2015. (Photo by Czarek Sokolowski/AP Photo)

An alpaca chewing a leaf is pictured on November 18, 2014 in the zoo of Frankfurt am Main, Germany. (Photo by Frank Rumpenhorst/AFP Photo/DPA)

This bat gives a cheeky smile as he gobbles down his food at Singapore Zoo, on September 10, 2013. (Photo by Benny Iskander/HotSpot Media)

A Grevy’s zebra gets itself noticed at ZSL Whipsnade Zoo in Whipsnade, England on April 20, 2018. (Photo by Tony Margiocchi/Barcroft Media)

An orange oakleaf rests on a plant at the Taipei Zoo on November 26, 2020. (Photo by Sam Yeh/AFP Photo)

A chevrotain or mouse deer feeds in its enclosure at Zurich Zoo, Zurich, Switzerland, October 17, 2012. (Photo by Patrick B. Kraemer/AP)

A chimpanzee bottle-feeds a lamb at Southam Zoo Farm in Warwickshire. The owners of the zoo, Mr and Mrs Clews, bring up many of the animals as their pets; the animals, are, as a result, of a friendly disposition. (Photo by Fox Photos/Getty Images). 23rd August 1968

Florence the baby zebra foal, runs in its enclosure at Edinburgh zoo September 4, 2008 in Edinburgh, Scotland. This arrival at the zoo is particularly important as the Grevy's zebra is listed as endangered, with only an estimated 1,500 to 2,000 remaining in the wild. (Photo by Jeff J Mitchell/Getty Images)