A girl carries bottles of water filled from a charity tank at a camp for internally displaced people (IDPs) near Sanaa, Yemen on March 25, 2022. (Photo by Khaled Abdullah/Reuters)

A tourist carries her luggage in a flooded St. Mark's Square, in Venice, Wednesday, November 13, 2019. The high-water mark hit 187 centimeters (74 inches) late Tuesday, Nov. 12, 2019, meaning more than 85% of the city was flooded. The highest level ever recorded was 194 centimeters (76 inches) during infamous flooding in 1966. (Photo by Luca Bruno/AP Photo)

French celebrities show off dresses made with chocolate at the Paris chocolate fair on October 27, 2021 in Paris, France. From left: Gennifer Demey, a weather forecaster; Isabelle Vitari, an actress; and Alicia Aylies, Miss France 2017. (Photo by Laurent Viteur/Getty Images)

Children play on top of an abandoned car at the “Aguerridos Liberator” shanty town in Caracas, Venezuela, Thursday, May 9, 2019. (Photo by Rodrigo Abd/AP Photo)

People without face masks are seen at Times Square during the coronavirus disease (COVID-19) pandemic in New York City, U.S., March 11, 2021. (Photo by Eduardo Munoz/Reuters)

Iraqi teenagers swim in waste water from the nearby Tuweitha nuclear facility near Baghdad, Iraq on May 28, 2003. Iraqis are consuming contaminated water unaware of the dangerous pollutants that can cause severe ill health. (Photo by Damir Sagolj/Reuters)

Camila Iachini, 8, performs with her bike during celebrations for the 400th anniversary of the founding of the neighbourhood Petare, in Caracas, Venezuela on February 17, 2021. (Photo by Leonardo Fernandez Viloria/Reuters)

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)