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)

Shooting star by Tony Wu, US/Japan. Winner, underwater. The electrifying reproductive dance of a giant sea star. As the surrounding water filled with sperm and eggs from spawning sea stars, Wu faced several challenges. Stuck in a small, enclosed bay with only a macro lens for photographing small subjects, he backed up to squeeze the undulating sea star into his field of view. The dancing posture of spawning sea stars rising and swaying may help release eggs and sperm, or may help sweep the eggs and sperm into the currents where they fertilise together in the water. Kinko Bay, Japan. (Photo by Tony Wu/Wildlife Photographer of the Year)

Belarus' Aryna Sabalenka poses with the 2023 Australian Open winner's trophy in Royal Botanic Garden in Melbourne on January 29, 2023, following her victory over Kazakhstan's Elena Rybakina in the women's singles final of the tennis tournament. (Photo by Carl Recine/Reuters)

A Somali family wades through flood waters, as they flee after overnight rains destroyed their home, in Wadajir district of Mogadishu, Somalia on May 10, 2025. (Photo by Feisal Omar/Reuters)

A technician disinfects official balls before the Group F Africa Cup of Nations (CAN) 2021 football match between Mauritania and Gambia at Limbe Omnisport Stadium in Limbe on January 12, 2022. (Photo by Issouf Sanogo/AFP Photo)

South Korean performers participate in a re-enactment of the battle of the Korean war during the ceremony to mark the 70th anniversary of the Korean War in Cheorwon, near the border with North Korea on June 25, 2020 in Cheorwon, South Korea. Over 66,000 South Koreans have been separated from their families during the Korean War which started on June 25, 1950, and effectively split the Korean Peninsula into two over the 3-year conflict. (Photo by Chung Sung-Jun/Getty Images)

Anti-pollution protesters wearing traditional costumes and contemporary gas masks ride bicycles in the Qingming Grand river park in Kaifeng, Henan Province, China on January 1, 2017. The Beijing Municipal Environmental Protection Bureau extended an “orange alert” for heavy air pollution for three more days. (Photo by SIPA Asia/Rex Features/Shutterstock)

Revelers celebrate during fireworks marking the start of the New Year on Copacabana beach on January 1, 2017 in Rio de Janeiro, Brazil. Brazilian revelers traditionally dress in white to honor the New Year's holiday along with the Brazilian Goddess of the Sea- Iemanja. (Photo by Mario Tama/Getty Images)