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)

Revellers out and about in Newcastle, England on “Black Eye Friday” or “Mad Friday” on December 22, 2017 as people across the country celebrate the start of the Christmas break by hitting bars, pubs and clubs. This partygoer had so much fun she looks lost. (Photo by Craig Connor/North News and Pictures)

Elsa, Dolly, Jeanie, Vince, Titch and Bailey savour seaside smells at Reculver Towers and Roman Fort, Kent, United Kingdom on February 23, 2021. The southeast of England will be warm again. (Photo by Liz Gregg/Triangle News)

A person rides a swing hanging from a crane with hot air balloons fly in the background in Nevsehir, Turkey on October 14, 2021. Tourists and those who want to take photos set up swings on the cranes they rent and then have their photos taken in the setting created by hot air balloons in the backgrounds. (Photo by Behcet Alkan/Anadolu Agency via Getty Images)

Israeli soldiers detain a protester during a demonstration by Palestinians protesting against the Israeli-built West Bank separation barrier and calling for the right of return for Palestinian refugees, in the northern West Bank city of Tulkarem, on May 31, 2014. (AP Photo/Nasser Ishtayeh)

A wax figure of President William Howard Taft is seated in the front seat with his detached head in the back after it was purchased from an auction of the Hall of Presidents Museum, which closed in November, in Gettysburg, Pennsylvania, U.S. January 14, 2017. (Photo by Mark Makela/Reuters)

An Indigenous schoolchild dressed in traditional attire takes part in a rally to commemorate Indigenous Resistance Day in Catarina town, Nicaragua October 12, 2016. This holiday coincides with Columbus Day which commemorates Christopher Columbus landing in America in 1492. But rather than celebrating the discovery of the Americas, the Nicaraguans observe Indigenous Resistance Day to celebrate the bravery of the indigenous population in the fight against the Spanish conquistadors. (Photo by Oswaldo Rivas/Reuters)