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)

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)

A hint of Spring Fever is evidenced by this passerby tipping his hat to a store fixture mannequin on a State St. sidewalk in downtown Chicago on March 23, 1978. The mannequin was awaiting pickup to be transported. (Photo by AP Photo)

Nigerian make-up artist, Mary Oni, creates artwork on her chest using make-up, in her home in Lagos, Nigeria on January 26, 2022. (Photo by Seun Sanni/Reuters)

Pregame scenes from the game between the Georgia Bulldogs against the Samford Bulldogs at Sanford Stadium in Athens, Georgia on September 9, 2022. (Photo by Dale Zanine/USA TODAY Sports)

A model wears a creation for the Rick Owens ready-to-wear Spring/Summer 2023 fashion collection presented Thursday, September 29, 2022 in Paris. (Photo by Francois Mori/AP Photo)

Racegoers try to shelter from the rain during day one of the Cazoo Derby Festival at Epsom Racecourse in Surrey, United Kingdom on Friday, June 4, 2021. (Photo by John Walton/PA Images via Getty Images)

Italy's Sofia Raffaeli competes in the individual all-around final during the Rhythmic Gymnastics World Championships at the West Japan General Exhibition Centre in Kitakyushu, Fukuoka prefecture on October 30, 2021. (Photo by Charly Triballeau/AFP Photo)