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 woman walks past a stall at a market in Banjul, Gambia December 15, 2016. (Photo by Afolabi Sotunde/Reuters)

A baby Black-crowned Night Heron squawks in its incubator while being cared for at City Wildlife rescue and rehabilitation center in Washington, DC on May 31, 2017. The heron is one of several that have been brought to CW by the staff at The National Zoo over the past few years. (Photo Linda Davidson/The Washington Post)

People walk along the sea front at Blyth in Northumberland in North East England on Monday, May 24, 2021. (Photo by Owen Humphreys/PA Images via Getty Images)

Women wearing traditional dresses dance next to Cathedral–Mosque of Cordoba, Andalusia, Spain, 26 May 2021, to celebrate the Cordoba Fair that was suspended due to coronavirus COVID-19 pandemic for a second consecutive year. The Cordoba Fair is held every year in May for a week during which flamenco, food, and wine are the main attractions for thousands of people. (Photo by Salas/EPA/EFE)

A model practices her walk ahead of Dakar fashion week on Goree Island in Dakar, Senegal, on December 03, 2022. The 20th anniversary of Dakar fashion week is held in a preserved colonial era fort on Goree island, which was one of Africas biggest slave trading centres during the 15th and 16th century. (Photo by John Wessels/AFP Photo)

A young Iraqi shepherdess cools down buffaloes in wastewater filling the dried-up Diyala river which was a tributary of the Tigris, in the Al-Fadiliyah district east of Baghdad, on June 26, 2022. (Photo by Ahmad Al-Rubaye/AFP Photo)

Samba dancers outside Woolwich station celebrate the opening of the Elizabeth Line in London, England on May 23, 2022. Originally due to open in December 2018, the £18.8bn railway links Reading and Essex via central London. (Photo by Jill Mead/The Guardian)