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)

Elvis Presley impersonator Sean Wright poses next to the Elvis Express train at Sydney's Central station before it departs for the 26th annual Elvis Festival being held in the New South Wales town of Parkes in Australia, January 11, 2018. (Photo by Daniel Munoz/Reuters)

Russia' s Tiffani Zagorski and Russia' s Jonathan Guerreiro compete in the ice dance free dance of the figure skating event during the Pyeongchang 2018 Winter Olympic Games at the Gangneung Ice Arena in Gangneung on February 20, 2018. (Photo by Lucy Nicholson/Reuters)

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)

Women sell bananas in the street, after traders in markets were prohibited from selling any non-food items in an attempt to halt the spread of the new coronavirus, in Kampala, Uganda Thursday, March 26, 2020. (Photo by Ronald Kabuubi/AP Photo)

Jude Hajjaj, carries her cat near a picture of her cat painted on the wall by her father Osama Hajjaj, who teams up with his neighbours in creating works of art at their roof during the curfew imposed by the Jordanian government amid concerns over the spread of the coronavirus disease (COVID-19) in Amman, Jordan, May 10, 2020. (Photo by Muhammad Hamed/Reuters)

An artwork called “Beyond Crisis” by French artist Guillaume Legros aka Saype and created with an eco paint made out of chalk and coal over a 3000 sqm field is pictured during the coronavirus disease (COVID-19) outbreak in Leysin, Switzerland, April 24, 2020 in this picture obtained by Reuters April 26, 2020. (Photo by Valentin Flauraud/SAYPE/Handout via Reuters)

Nina Betschart of Team Switzerland dives against Germany during the Women's Preliminary - Pool F on day one of the Tokyo 2020 Olympic Games at Shiokaze Park on July 24, 2021 in Tokyo, Japan. (Photo by Sean M. Haffey/Getty Images)