A hippopotamus performs during a show at the circus in Krasnoyarsk, Siberia, Russia, July 7, 2016. (Photo by Ilya Naymushin/Reuters)

Female Siberian tiger Dasha yawns in the new enclosure at the zoo in Duisburg, Germany, 30 March 2016. The new facility is three times larger than the old one and will be opened to the public on the same day. (Photo by Roland Weihrauch/EPA)

In this picture taken Thursday, August 4, 2016, seal Tristan looks out of a basket while being released into the North Sea together with others at the beach of the island Juist, Germany. He is part of the first group of released seals of the seal breeding station Norddeich this year. (Photo by Carmen Jaspersen/DPA via AP Photo)

Pigeons cool down at a public fountain on a hot summer day at University Plaza in downtown Bucharest, Romania, 10 June 2020. Temperatures in Bucharest reached 30 degrees Celsius. (Photo by Robert Ghement/EPA/EFE)

Almost two years old male baby orang-utan Dalai looks on in the zoo in Dresden, Germany, 30 March 2017. Dalai was born to mother Daisy in June 2016. (Photo by Filip Singer/EPA)

A baby bush-baby in a set of scales at London Zoo shortly after birth. (Photo by Fox Photos/Getty Images). 10th August 1938

A koala named Lisa from Pappinbarra recovers from burns at The Port Macquarie Koala Hospital on November 29, 2019 in Port Macquarie, Australia. Volunteers from the Koala Hospital have been working alongside National Parks and Wildlife Service crews searching for koalas following weeks of devastating bushfires across New South Wales and Queensland. Koalas rescued from fire grounds have been brought back to the hospital for treatment. An estimated million hectares of land has been burned by bushfire across Australia following catastrophic fire conditions in recent weeks, killing an estimated 1000 koalas along with other wildlife. (Photo by Nathan Edwards/Getty Images)

A golden pheasant is seen at Hangzhou Safari Park in Hangzhou, Zhejiang Province, China, November 13, 2016. According to local media, the pheasant gains popularity as its golden feathers resemble the hairstyle of U.S. President-elect Donald Trump. (Photo by Reuters/Stringer)