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)

ESA astronaut Samantha Cristoforetti on the International Space Station 3 February 2015 during her Futura mission. Samantha is living and working on the Station as part of the Expedition 42 crew. Picture released on February 10, 2015. (Photo by ESA/NASA)

A man reacts as he tries to extinguish a burning Christmas tree at Festival Walk mall in Kowloon Tong, Hong Kong, November 12, 2019. Anti-government protesters smashed windows and set fires in the mall on Tuesday, including to a big Christmas tree. (Photo by Thomas Peter/Reuters)

Workers polish a snow sculpture ahead of the 16th Harbin Ice and Snow World in Harbin, Heilongjiang province, December 22, 2014. The 16th Harbin Ice and Snow World will be officially opened on January 5, 2015. (Photo by Reuters/Stringer)

A horse trainer takes his horse into the water at Pebble Beach on June 28, 2024 in Bridgetown, Barbados. The swimming horses of Barbados offer a unique and remarkable experience at Pebbles Beach, where racehorses from the nearby Garrison Savannah enjoy their morning swim almost daily between 5:30 am and 7 am. During this ritual, horses swim out surprisingly far to the moored boats before returning to shore, with some staying longer in the water if recovering from injury or soreness after a race. Visitors can observe the horses' individual personalities as they swim and interact with the water, but are advised to respect the guidance of the grooms and maintain a safe distance, as horses can behave unpredictably, especially if frightened. (Photo by Robert Cianflone/Getty Images)

Daniel Sheridan, a council worker from Poole, Dorset, runs a side hustle snapping dogs living their best lives in the second decade of December 2024. (Photo by Daniel Sheridan/South West News Service)

Xiren Wang, Lili Wat, and Sitong Chen join the pageant’s opening routine, dancing to “The Boys”, a song by K-Pop group «Girls’ Generation». While the women come from a range of professional backgrounds – including economics, nursing, and acting – every contestant is looking for her big break into the entertainment industry. Most contestants said they would prefer to have a career in the U.S. but would go wherever the opportunity lies. (Photo and caption by John Brecher/Sahra Vang Nguyen/NBC News)

Fighting Infections (single image) | Fighting Pandemic by Sudipto Das. “It’s exhausting. A tram conductor in Kolkata, India, wears protective clothing from head to toe even in the heat of a summer afternoon. This was when restrictions were easing after India’s first Covid-19 lockdown – public transport was running, but staff were advised to suit up like this. We’ve all grown used to saluting the efforts of healthcare workers, but plenty of other people in public-facing jobs have performed gruelling duties too to keep people safe”. (Photo by Sudipto Das/Wellcome Photography Prize 2021)