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 window cleaner passes a lighter to his colleague while rappelling from a new building in Tianjin March 23, 2007. (Photo by Reuters/Stringer)

Ring-tailed lemurs sit on the hood of a truck while snacking inside the Buin Zoo in Santiago, Chile, Tuesday, June 15, 2021. The largest private zoo in Chile, experiencing a serious economic situation due to the closure of its doors as a result of the prolonged quarantine measures, has started a campaign coined, “Sponsor an Animal”, to raise money to maintain the animals. (Photo by Esteban Felix/AP Photo)

A flying lemur glides through the air in West Java, Indonesia in the first decade of October 2023. The photographer said the animal veered away from him at the last minute. (Photo by Dzul Dzulfikri/Animal News Agency)

A confiscated pet lion poses with a dog as it arrived back home from the Phnom Tamao Wildlife Rescue Center after Prime Minister Hun Sen ordered authorities to return the animal in Phnom Penh, Cambodia, July 5, 2021. (Photo by Cindy Liu/Reuters)

Workers produce Bing Dwen Dwen plush toys at the workshop of Jinjiang Hengsheng Toys Co., Ltd. on February 8, 2022 in Jinjiang, Fujiang Province of China. (Photo by VCG/VCG via Getty Images)

Adrienne Yip takes a picture of her Burmese mountain dog named “Walter”, beneath the cherry blossoms in peak bloom at the Tidal Basin with the Washington Monument seen behind, in Washington, DC, USA, 18 March 2024. Peak bloom, as defined when seventy percent of the cherry blossoms are open, is occuring this week. This year's peak bloom, beginning the 17th of March, is tied for the second earliest in history and is seen as a reflection of warming temperatures. (Photo by Michael Reynolds/EPA/EFE/Rex Features/Shutterstock)

Revellers hit the town on Saturday, February 19, 2022 for a pub crawl despite the snow in Leeds, United Kingdom. The UK capital was placed under its first ever “red” weather warning, meaning there is “danger to life”. The same level of alert was in place across southern England and South Wales, where schools were closed and transport paralysed. (Photo by Nb press ltd)