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)

Pierre Thivillon (R), director of the zoological park of Saint-Martin-La-Plaine and his wife Eliane look at Digit, an 18-year-old female gorilla, on August 19, 2016, in Saint-Martin-La-Plaine between Lyon and Saint-Etienne, southeastern France. The zoological park of Saint-Martin-La-Plaine is a shelter for beasts seized by the justice. (Photo by Philippe Desmazes/AFP Photo)

An Indian white tiger cools off in a pond in its enclosure at Chhat Bir Zoo on the outskirts of Chandigarh on May 22, 2016. Temperatures have soared to a scorching 51 degrees Celsius in one Indian city, meteorologists said, with the ferocious heat setting a new national record. Northern Phalodi wilted as the mercury reached a new high on May 20, equivalent to 123.8 Fahrenheit, beating a 60-year-old record. (Photo by Shammi Mehra/AFP Photo)

A Puffin jumps into its burrow with a mouthful of sea eels to feed its chick on Skomer Island, Pembrokeshire in Wales, Britain June 21, 2016. (Photo by Rebecca Naden/Reuters)

Two stallions confront each other at a horse fighting contest in Rongshui, China. More than 30 horses from surrounding regions took part in the traditional activity of the Lantern festival. (Photo by China Foto Press)

Two dogs sent into outer space by the Soviet Union after their safe return to earth. They spent 22 days in orbit. (Photo by Central Press/Getty Images). 22nd March 1966

A Humboldt penguin swims in a pool during the annual stock take at ZSL London Zoo in London, Thursday, January 2, 2020. Caring for more than 500 different species, ZSL London Zoo's keepers face the challenging task of tallying up every animal large and small, every mammal, bird, reptile, fish and invertebrate at the Zoo. (Photo by Frank Augstein/AP Photo)

A brushtail possum whose ears and legs have been burnt from recent bushfires sits in a cage before being transported to a wildlife hospital, in Batemans Bay, South of Sydney, Australia, 14 January 2020. (Photo by Steven Saphore/EPA/EFE)