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

A zoo keeper feeds Diego, a three month old howler monkey, which is reared at Edinburgh Zoo, July 29, 2008 in Scotland. (Photo by Jeff J. Mitchell/Getty Images)

A panda bear sits on a logs in a zoo on January 15, 2015 in Hangzhou, China. (Photo by Feature China/Barcroft Media)

A Chimpanzee opens its Christmas presents at ZSL Whipsnade Zoo on December 17, 2013 in Bedfordshire, England. (Photo by Tony Margiocchi/Barcroft Media)

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)

A painted stork eats a fish as it is pictured in the Delhi Zoo in New Delhi on December 5, 2024. (Photo by Sajjad Hussain/AFP Photo)

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)

An Amur tiger walks across a passageway after a news conference at the Philadelphia Zoo, Wednesday, May 7, 2014, in Philadelphia. The see-through mesh pathway called Big Cat Crossing is part of a national trend called animal rotation that zoos use to enrich the experience of both creatures and guests. (Photo by Matt Slocum/AP Photo)