A red deer stag takes a mud bath in Wollaton Park near Nottingham, England on May 23, 2020. Gareth Williams, who took the photograph, said it was a “once in a lifetime shot”. (Photo by Gareth Williams/Kennedy News)

A crab-eating fox (Cerdocyon thous), also known as the forest fox, wood fox, or maikong, is seen in the wild in the municipality of Guasca, some 50 km from Bogota, on May 16, 2020. (Photo by Diana Sánchez/AFP 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)

A chimpanzee in the Osnabrück Zoo in Lower Saxony makes contact with a small zoo visitor sitting in front of a pane on September 1, 2020. The two males Lobo and Lome moved from Leipzig Zoo to Osnabrück Zoo to strengthen the social structure of the existing group. (Photo by Friso Gentsch/dpa)

A photographer with a hidden camera took 2,500 photos before this elusive badger was ready for his close-up in September 2020. (Photo by Andy Swinden/BNPS)

Photo taken on October 11, 2020 shows a golden monkey at Dalongtan Golden Monkey Research Center in Shennongjia National Park of central China's Hubei Province. With the efforts of local authority and improvement of the environment in the past many years, the number of golden monkeys in Shennongjia area reached nearly 1,500 nowadays. (Photo by Xinhua News Agency/Rex Features/Shutterstock)

Pistachio, a puppy who was born with green fur, is seen on the day he was born on a farm on the island of Sardinia, in Pattada, Italy, October 9, 2020. (Photo by Cristian Mallocci/Handout via Reuters)

A red squirrel sniffs out nuts inside Christmas stockings as part of the festive celebrations and enrichment programme at Wildwood Escot Park in Ottery St Mary, Devon, United Kingdom on December 17, 2020. (Photo by Ben Birchall/PA Images via Getty Images)