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)

Belarusian ornithologist Vladimir Ivanovski, 72, stands on a tree as he builds an artificial nest for birds of prey from tree branches, in a marsh near the village of Kazyany, Belarus on October 20, 2019. (Photo by Vasily Fedosenko/Reuters)

Picture show a 39-foot whale that was crushed to death hanging lifelessly over the bow of a tanker in Japan. Horrified locals caught sight of the whale as the ship pulled into the harbour of Kurashiki last month, September 2021. (Photo by Newsflash)

A French bulldog wears a costume at the annual Pet Expo 2021 in Bangkok, Thailand on November 25, 2021. (Photo by Athit Perawongmetha/Reuters)

Oil pools in a leaf on the beach following an oil slick at Tanjong Beach in Sentosa, Singapore on June 15, 2024. (Photo by Edgar Su/Reuters)

Long-eared owl chicks sit on a spruce branch in a park near St Petersburg, Russia on March 3, 2025. (Photo by Artem Priakhin/SOPA Images/Rex Features/Shutterstock)

A member of Sisters of the Valley, a non-religious international group founded in 2014 which has pledged to spread the gospel of the healing powers of cannabis, who uses the moniker “Sister Bernardet” online and asked not to give her name for fear of reprisal, smokes a joint at the Sisters of the Valley's farm on the outskirts of a village in central Mexico on September 3, 2023. (Photo by Raquel Cunha/Reuters)

Miniscule larvae carve winding tunnels as they eat through small leaves in a small forest near the town of Velbert in western Germany in July 2022. The hungry green sawfly larvae measure just three millimetres in length and are difficult to spot on the leaves of the beech tree unless up close. (Photo by Christian Brockes/Solent News)