Two citizens splash hot water which is quickly frozen in the cold air on January 7, 2021 in Beijing, China. A strong cold wave sweeps across China as the Chinese capital Beijing recorded 19.5 Celsius below zero on 06 January morning, the lowest temperature since 1966, according to meteorological authorities. (Photo by Peng Yucai/VCG via Getty Images)

A pro-Palestinian demonstrator reacts as she is escorted by security personnel after scuffling with an observer, as protesters in support of Palestinians in Gaza and pro-Israel counter-protesters gather at the encampment on the campus of the University of California Los Angeles (UCLA), amid the ongoing conflict between Israel and the Palestinian Islamist group Hamas, in Los Angeles, California, U.S. April 29, 2024. (Photo by David Swanson/Reuters)

Yanick Wasser of Switzerland jumps in the Mens Large Hill Individual competition during Day 2 of the FIS Ski Jumping World Cup at Lake Placid Olympic Jumping Complex on February 08, 2025 in Lake Placid, New York. (Photo by Al Bello/Getty Images)

US M142 High Mobility Artillery Rocket System (HIMARS) is launched as journalists film during a military exercise in Capas, Tarlac province, Philippines, 13 October 2022. The Philippines hosted simultaneous combat drills with the United States, South Korea, and Japan to improve interoperability in times of conflict. (Photo by Francis R. Malasig/EPA/EFE)

Raining on their New Year's Eve parade. Revellers in Leeds, United Kingdom get ready ready for the new year on December 31, 2022. (Photo by Nb press ltd)

A grey squirrel looks for some food from a girl in the Botanic Gardens in Glasnevin, Dublin, Ireland on April 3, 2023. (Photo by Damien Eagers/The Irish Times)

An iguana rests on a man's head during a pet blessing ceremony a day after World Animal Day, at a mall in Quezon City, Metro Manila, Philippines on October 5, 2025. (Photo by Noel Celis/Reuters)

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)