Buyan, a male Siberian brown bear, is given a shower by a zoo employee in his enclosure at the Royev Ruchey zoo in Russia's Siberian city of Krasnoyarsk June 24, 2014. The Siberian city has been experiencing temperatures of around 30 degrees Celsius over the last week. (Photo by Ilya Naymushin/Reuters)

Two hippopotamus are fed with pumpkins at the Hanoi Zoo, in Hanoi, Vietnam, 25 October 2018. The zoo has been the home for more than 800 animals of over 90 different species, including three hippopotamus, since it was built in 1976. (Photo by Luong Thai Linh/EPA/EFE)

A handout image released by the Taronga Zoo shows Veiled Chameleon hatchlings at Taronga Zoo in Sydney, Australia, 11 March 2015. Taronga has welcomed more than 20 baby chameleons, with the last of three clutches of eggs hatching this week. Veiled Chameleons, or Chamaeleo calyptratus, are native to Saudi Arabia and Yemen and can live up to five years. (Photo by EPA/Taronga Zoo)

A ten days old South American sea lion pup sits next to its mother Lunita at the “Tiergarten Schoenbrunn” Zoo in Vienna, Austria, July 28, 2015. The pup was born in the zoo and weighs about 14 kilograms (30 pounds). (Photo by Leonhard Foeger/Reuters)

Ukrainian state emblem is seen on a gun's holster as soldiers guard naval base in the village of Novoozernoye, some 91 km west of Crimean capital Simferopol, Ukraine, on Monday, March 3, 2014. Ukraine says Russian forces controlling the strategic region of Crimea are demanding that the crew of two Ukrainian warships in Sevastopol's harbor must surrender. (Photo by Ivan Sekretarev/AP Photo)

Members of the U.S. Army 173rd Airborne Brigade stand at attention as a Ukrainian folk dance group performs at the opening ceremony of the “Rapid Trident” NATO military exercises on September 15, 2014 near Yavorov, Ukraine. The two-week exercises include participating units from a variety of NATO and NATO-associate countries as well as Ukrainian troops. Meanwhile fighting between pro-Russian separatists and Ukrainian armed foces has flared again in eastern Ukraine in a battle for the control of Donetsk airport despite the tenuous ceasefire. (Photo by Sean Gallup/Getty Images)

Ukrainians attend an open military training for civilians on a training range in Kiev, Ukraine, 30 January 2022. According to a survey conducted by the Kiev International Institute of Sociology (KIIS) from December 2021, 50.2 percent of Ukrainians said they would resist in case of a Russian military intervention into their city, town or village. Every third respondent to the poll said they were ready to engage in armed resistance, and 21.7 percent said they were ready to participate in civil resistance actions. (Photo by Sergey Dolzhenko/EPA/EFE)

Ukrainians attend an open military training for civilians on a training range in Kiev, Ukraine, 06 February 2022. According to a survey conducted by the Kiev International Institute of Sociology (KIIS) from December 2021, 50.2 percent of Ukrainians said they would resist in case of a Russian military intervention into their city, town or village. Every third respondent to the poll said they were ready to engage in armed resistance, and 21.7 percent said they were ready to participate in civil resistance actions. (Photo by Sergey Dolzhenko/EPA/EFE/Rex Features/Shutterstock)