The six-months-old female koala cub holds on to the back of zoo keeper Lena at the zoo in Duisburg, Germany, 23 October 2015. The yet unnamed baby weighs 580 grams. (Photo by Roland Weihrauch/EPA)

Giant panda Meng Meng plays on a tree at a Siberian tiger-breeding base in Changchun, China on December 10, 2015. (Photo by Xu Chang/Xinhua Press/Corbis)

An injured vulture is treated at the VulPro Vulture Rehabilitation Centre in Hartebeepoortdam in the Magalisburg region on September 15, 2015. Confined to southern Africa, just under 4,000 breeding pairs of Cape Vultures remain in the wild, mostly in South Africa, Lesotho and Botswana. Unless conservation efforts are successful, Africa's largest vulture species may be facing eventual extinction. (Photo by Mujahid Safodien/AFP Photo)

A dog sits in a plastic tub filled with water in Taipei, Taiwan, 28 July 2020. Betel nut seller Mr Luo, the dog's owner, said he puts his dog, a 12-year-old mixed breed called Ah Dai (Stupid), in a plastic tub filled with water whenever the weather gets hot. Ah Dai enjoys the bath and can sit in the basin for hours, according to Mr Luo. Luo has a dozen pairs of glasses for Ah Dai, so the dog wears different glasses every day and many tourists take photos of Ah Dai. (Photo by David Chang/EPA/EFE)

A brown bears cools off in a pool at the bear sanctuary near the village of Mramor, on August 18, 2020. The bear sanctuary was closed for visitors on August 18, as part of safety measures to curb the spread of the COVID-19 (novel coronavirus) disease. (Photo by Armend Nimani/AFP Photo)

The Sea Life Trust team move Beluga Whale Little Gray from a tugboat during transfer to the bayside care pool where they will be acclimatised to the natural environment of their new home at the open water sanctuary in Klettsvik Bay in Iceland on August 7, 2020. The two Beluga whales, named Little Grey and Little White, are being moved to the world's first open-water whale sanctuary after travelling from an aquarium in China 6,000 miles away in June 2019. (Photo by Aaron Chown/PA Images via Getty Images)

Tatyana Abramova, 33, plays with her home fox Plombir at her countryside house outside Siberian city of Novosibirsk on September 12, 2020. The official start of the Soviet experiment to better understand the domestication of animals by humans began in 1959, and was initiated by geneticists Dmitri Beliaiev and Lioudmila Trout on a farm in Akademgorodok, the scientific center of excellence in Siberia. Their primary objective was to domesticate foxes, to understand how the ancestor of wolves, another canine, evolved into a loyal and loving dog. And understand what this domestication tells us about the genetic evolution of species. (Photo by Alexander Nemenov/AFP Photo)

A lion rests in the Nairobi National Park, Kenya on January 6, 2021. (Photo by Tiksa Negeri/Reuters)