Participants of the “Lady in red“ procession, marking the day of the Summer Solstice, walk on a promenade of the Yenisei River in Krasnoyarsk, Russia on June 22, 2019. (Photo by Ilya Naymushin/Reuters)

A man walks on a slackline during the 7th edition of the European “Marmotte Highline Project” (MHP) festival in Lans-en-Vercors, near Grenoble, eastern France, on July 4, 2019. The event, during which the participants will be able to evolve on the various highlines located in the Regional Natural Park of Vercors, takes place until July 7, 2019. (Photo by Philippe Desmazes/AFP Photo)

Big waves approach the beach of Nazare, Portugal, Tuesday, March 26, 2024. The high waves were caused by strong winds at one of the world's most popular surf spots. (Photo by Michael Probst/AP Photo)

A Buddhist nun walks along a path as a stupa is seen at a temple in Anuradhapura, Sri Lanka October 16, 2016. (Photo by Dinuka Liyanawatte/Reuters)

People pose for pictures on the banks of Yangtze River on New Year's Eve in Wuhan, in China’s central Hubei province on December 31, 2020. (Photo by Noel Celis/AFP Photo)

A recently hatched baby Egret bird seen in a nest at the Gatorland Bird Rookery in Kissimmee, Florida on March 17, 2022. Gatorland is known as The Alligator Capital of the World and has a 10 acre natural bird rookery. (Photo by Ronen Tivony/SOPA Images/Rex Features/Shutterstock)

Russian model Irina Shayk arrives on September 4, 2022 for the screening of the film “L'Immensita” (Immensity) presented in the Venezia 79 competition as part of the 79th Venice International Film Festival at Lido di Venezia in Venice, Italy. (Photo by Guglielmo Mangiapane/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)