Female of pygmy hippopotamus called Malaya from Netherlands in zoo in Dvur Kralove nad Labem, Czech Republic, February 22, 2016. (Photo by David Tanecek/CTK via ZUMA Press)

Actress Shae Mitchell arrives at REVOLVE Desert House on April 16, 2016 in Thermal, California. (Photo by Ari Perilstein/Getty Images for A-OK Collective, LLC.)

Behaviour: Mammals category. Giant Gathering by Tony Wu, USA. Dozens of sperm whales mingled noisily off Sri Lanka’s northeast coast, stacked as far down as Tony could see. This was a congregation of dozens of social units, like a gathering of the clans. Aggregations like this could be a critical part of the whales’ rich social lives but are rarely reported. Some two thirds of the population was wiped out before commercial whaling was banned in 1986. This kind of major gathering could be “a sign that populations are recovering”, says Tony. (Photo by Tony Wu/Wildlife Photographer of the Year 2017)

Rescuers attempt attempt to push stranded whales back into the ocean at Ujong Kareng beach in Aceh province, Indonesia, Monday, November 13, 2017. An official said a small pod of whales was stranded at the beach and attracted hundreds of onlookers who posed for pictures with them. (Photo by AP Photo/Zulkarnaini)

A participant Saint Nicholas parade walks from house to house dressed in the traditional devil and Nicholas costumes in Francova Lhota district of Zlin, Czech Republic on December 3, 2017. This type of parade is one of the most popular age old tradition in a few villages in Wallachia region (eastern part of Czech Republic). Saint Nicholas walks the streets going from house to house three days and Saint Nicholas gives sweets to children and the devils get up to mischief. (Photo by Lukas Kabon/Anadolu Agency/Getty Images)

Actress Hayley Hasselhoff leads models, diversity campaigners and social media influencers question the lack of curves in the female fashion industry outside 180 The Strand on February 16, 2018 in London, England. (Photo by Neil P. Mockford/Getty Images)

Children enjoy a sledge ride past ice swimming fans at the Zalew Zegrzynski lake in Nieporet, Poland, Sunday, February 25, 2018. A cold wave hit Poland with the temperature minus 8 degree Celsius (17.6 Fahrenheit) during the day and dropping to minus 16 degree Celsius (3.2 Fahrenheit) in the night in central Poland. (Photo by Alik Keplicz/AP Photo)

Female Iraqi Kurdish peshmerga fighters watch on as they release a bear into the wild in the Gara Mountains near the northern Iraqi city of Dohuk on March 4, 2018, after Iraqi Kurdish Animal rights activists from a local NGO rescued it from a private home. (Photo by Safin Hamed/AFP Photo)