Members of the Women's veteran movement take part in the March of Defenders of Ukraine as part of Ukraine's Independence Day celebrations, in Kyiv, Ukraine on August 24, 2020. (Photo by Gleb Garanich/Reuters)

Pals let their hair down for one last hoorah in Cardiff, capital of Wales on September 12, 2020. Groups of friends crammed into pubs and restaurants to “go out in style” before the “rule of six” is enforced on Monday. (Photo by Huw Evans Picture Agency/The Sun)

Two guests pose prior to the Dolce & Gabbana 2021 women's spring-summer ready-to-wear collection during the Milan's fashion week in Milan, Italy, Wednesday, September 23, 2020. (Photo by Luca Bruno/AP Photo)

In a photo taken on November 4, 2020 visitors wearing traditional Korean hanbok dress walk beneath yellow ginko leaves in a courtyard at Gyeongbokgung palace in Seoul. (Photo by Ed Jones/AFP Photo)

A stag reacts as magpies and crows fuss over a resting stag as they feed on ticks from the fur of the deer herd roaming on the Ashton Court Estate, Bristol, in crisp and cold Autumnal weather on November 23, 2020. (Photo by Ben Birchall/PA Images via Getty Images)

A family poses for photos near a dinosaur exhibits along the Changi Jurassic Mile as it is light up for Christmas near Changi airport in Singapore on December 8, 2020. (Photo by Tim Chong/Reuters)

English model Kate Moss, left, and her daughter Lila Grace Moss wear creations for Fendi's Spring-Summer 2021 Haute Couture fashion collection presented Wednesday, January 27, 2021 in Paris, France. (Photo by Francois Mori/AP Photo)

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)