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)

A cow is seen on land that used to be under water, at the Aculeo Lagoon in Paine, Chile, May 14, 2018. (Photo by Matias Delacroix/Reuters)

Canada's Jean-Simon Desgagnes competes in the men's 3000m steeplechase final of the Pan American Games Santiago 2023 at the National Stadium in Santiago, on November 4, 2023. (Photo by Martin Bernetti/AFP Photo)

A woman throws an object at police vehicle during clashes as people gather at the Bois de la Cambre/Ter Kamerenbos park for a party called “La Boum 2” in defiance of Belgium's coronavirus disease (COVID-19) social distancing measures and restrictions, in Brussels, Belgium on May 1, 2021. (Photo by Yves Herman/Reuters)

Aerial view of pond cypress at Qinglongwan Forest Park near Ningguo, China on November 26, 2017. (Photo by Imaginechina/Rex Features/Shutterstock)

Two couples prepare to pose for their wedding pictures outside the Forbidden City in Beijing on October 31, 2022. (Photo by Wang Zhao/AFP Photo)

A 180 degrees rotated photograph shows the shadows of Polina (L), a six-year-old Belarusian first grade school girl, and her father, cast on the street while on their way to Polina's first day of school, which marks the traditional start of the academic year, in Minsk, Belarus, 02 September 2019. The start of a new academic year in Belarus, officially called Day of Knowledge, is a festive day for all school and university students in the country. (Photo by Tatyana Zenkovich/EPA/EFE)

A Hindu devotee moves toward the river Brahmaputra in a prostrate manner to perform rituals during Chhath Puja festival in Guwahati, in the northeastern Indian state of Assam, India, Thursday, November 7, 2024. (Photo by Anupam Nath/AP Photo)