A huge colony of Pacific Walrus on Arakamchechen Island in the Northern Bering Sea. (Photo by Francois Gohier/Ardea/Caters News)

A polar bear fast asleep at London Zoo. (Photo by Fox Photos/Getty Images). 1961

The Sphinx breed of cat “Adam vom Feisastern” of the German breeder Sabine Braeuer waits on a jury table during an annual International Pedigree Dog and Cat Show in Erfurt, Germany on June 10, 2012. (Photo by Jens Meyer/Associated Press)

A brown bear cub by the Khailyulya River in north-east Kamchatka, Russia on July 24, 2021. (Photo by Yuri Smityuk/TASS)

An adult specimen of Nannospalax (leucodon) montanosyrmiensis, a variant of the lesser mole-rat (Spalax leucodon) is pictured near Albertirsa, some 60 kilometers southeast of Budapest, Hungary, 12 May 2018. The critically endangered rodent lives in several isolated populations in the Carpathian Basin. (Photo by Sandor Ujvari/EPA/EFE)

In one of the planet’s most desolate and harsh terrains, the Altai Mountains which run from Siberia in Russia down to Mongolia’s Gobi Desert, hunting with eagles is currently only practiced by a handful of Kyrgyz and Kazakhs. This form of falconry, the practice of hunting with the aid of birds of prey, can be traced back as far as 4,000 years in Central Asia. Here: after a successful hunt, a proud hunter rewards his eagle by feeding it the lungs of the prey, which is considered the most highly prized part of the animal. (Photo by Tariq Zaidi/The Washington Post)

Children play amid icebergs on the beach in Nuuk, Greenland, June 5, 2016. (Photo by Alister Doyle/Reuters)

“Hippo Chase”. As we approached the camp the Selinda Reserve of northern Botswana our boat passed by a hippo resting in the water. I turned around to look back at the boat's wake and saw the hippo charging after us! The hippo must've been tired from an all-nighter because he was angry. He rose way up out of the water three times trying to chase our boat! He was coming at us with such force that he created a wake of his own. Photo location: Selinda Reserve of northern Botswana. (Photo and caption by Curtis Simmons/National Geographic Photo Contest)