People are seen at Avalon Beach on December 18, 2020 in Sydney, Australia. A cluster of Covid-19 cases on the northern beaches of Sydney has grown to 28, prompting NSW health officials to urge residents of affected suburbs to stay home. Traffic at Sydney Airport has increased as people rush to leave the city with several states imposing quarantine restrictions for New South Wales residents. (Photo by Jenny Evans/Getty Images)

A couple sit on the terrase of a cafe in Istanbul as seagulls fly over them on September 10, 2019. (Photo by Ozan Kose/AFP Photo)

A woman struggles to drink homemade alcohol poured from the mouth of an idol of “Swet Bhairab” during the annual Indra Jatra festival to worship Indra, Kumari and other deities and to mark the end of monsoon season in Kathmandu, Nepal on September 15, 2019. (Photo by Monika Deupala/Reuters)

Salt-resistant plants grow in sand made up of small fish bones on the shore of the Salton Sea before sunrise in an area where a controversial development would create a new town for nearly 40,000 people on the northwest shore of the biggest lake in California, the Salton Sea, on March 21, 2012 south of Mecca, California. (Photo by David McNew/Getty Images)

Models prepare backstage before a creation from the Saint Joy by Bian Huizhong during the China Fashion Week in Beijing on March 30, 2023. (Photo by Wang Zhao/AFP Photo)

Fans of US singer Taylor Swift, also known as a Swifties, queue to enter at the Melbourne Cricket Ground (MCG) for the first of Swift's three shows in Melbourne on February 16, 2024. Swift is playing to 260,000 fans over three concerts in Melbourne starting February 16 as part of her Eras World Tour. (Photo by William West/AFP Photo)

Tourists visit teamLab Planets Tokyo in Tokyo on January 10, 2025. Japan on January 15 will announce tourist figures for the year 2024, widely expected to break the record set in 2019. (Photo by Kazuhiro Nogi/AFP Photo)

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)