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)

Tourists enjoy blooming cherry blossoms at China Pharmaceutical University on March 22, 2021 in Nanjing, Jiangsu Province of China. (Photo by Yang Bo/China News Service via Getty Images)

Ana Mendez Casteñeda smokes marijuana during “Fumaton 420” outside the national Senate in Mexico City, Tuesday, April 20, 2021. The demonstrators are calling for the legalization of marijuana. (Photo by Marco Ugarte/AP Photo)

Annabelle, 13, and her sister Estelle, 10, both artistic gymnasts from Borna, hang from the rings during their training, ahead of the Special Olympics World Games Berlin 2023, the world's largest sports movement for people with intellectual disabilities, at the Federal base for competitive gymnastic artistics in Chemnitz, Germany on May 6, 2023. (Photo by Annegret Hilse/Reuters)

Zulu maidens sings and dance as they arrive for the coronation event, at the Moses Mabhida Stadium in Durban, South Africa, Saturday, October 29, 2022. South Africa President Cyril Ramaphosa on behalf of the government formally presented a certificate of recognition to His Majesty King MisuZulu ka Zwelithini of the AmaZulu. (Photo by Themba Hadebe/AP Photo)

A shop assistant creates a window display in a Next store in central London December 30, 2014. British clothing retailer Next's sales rose 2.9 percent in the run up to Christmas mostly due to online and catalogue purchases, hitting the upper end of its predictions and it said full-year profit would rise by about 11.5 percent. (Photo by Neil Hall/Reuters)

Zulmira Jesus poses for a portrait at a street in Povoa de Agracoes, near Chaves, Portugal April 19, 2016. In the villages of Agracoes and Povoa de Agracoe, the steady drip-drip of emigration has brought down population numbers from more than 50 residents to fewer than a dozen each. These remaining villagers share the same glum acceptance that, after they have gone, their villages will die out too. It is the same desolate picture in scores of other backwater settlements in Portugal's interior, north to south. (Photo by Rafael Marchante/Reuters)

Disguised revellers parade on the occasion of the Cortege during the Carnival in Basel, Switzerland, February 17, 2016. (Photo by Georgios Kefalas/EPA)