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)

The carcass of a fattened pig, winner of the “holy pig” contest, is attached to a metal frame during a sacrificial ceremony in Sanxia district, in New Taipei City, Taiwan February 1, 2017. The winner of Taiwan's “holy pig” ceremony on Thursday defended the lunar new year tradition against critics who argue the fattened animals are raised under cruel conditions. (Photo by Tyrone Siu/Reuters)

A woman fancy dressed as Catrina takes part in the “Catrinas Parade” along Reforma Avenue, in Mexico City on October 26, 2019. Mexicans get ready to celebrate the Day of the Dead highlighting the character of La Catrina which was created by cartoonist Jose Guadalupe Posada, famous for his drawings of typical local, folkloric scenes, socio-political criticism and for his illustrations of “skeletons” or skulls, including La Catrina. (Photo by Claudio Cruz/AFP Photo)

Celebrities attend The National Reality TV Awards 2016 at the Porchester Hall in London, United Kingdom on September 29, 2016. (Photo by FameFlynet UK)

Danielle Sellers attends The Beauty Awards at Tower of London on November 28, 2017 in London, England. (Photo by Lia Toby/WENN)

Ricky Rebel attends the 62nd Annual GRAMMY Awards at Staples Center on January 26, 2020 in Los Angeles, California. (Photo by Mike Blake/Reuters)

Shortlisted: Sólheimasandur aircraft crash site, Iceland by Ollie Conway. (Photo by Ollie Conway/Historic Photographer of the Year Awards 2019/The Guardian)

English actress Kate Beckinsale attends the GQ Men of the Year Awards at Tate Modern on September 5, 2018 in London, England. (Photo by Karwai Tang/WireImage)