A boy dressed as Lord Krishna is pictured while Hindu devotees march on the streets to celebrate Janmashtami festival, which marks the birth anniversary of Lord Krishna, in Dhaka, August 14, 2017. (Photo by Mohammad Ponir Hossain/Reuters)

Young girls perform in front of the monument to Soviet state founder Vladimir Lenin during the City Day celebrations in Yekaterinburg, Russia on August 19, 2017. (Photo by Maxim Shemetov/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)

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)

British underwater photographer of the year 2021, British waters wide angle category winner and My Backyard category winner. While You Sleep by Mark Kirkland (United Kingdom), common frog taken in Malls Mire, Glasgow, Scotland. (Photo by Mark Kirkland/Underwater Photographer of the Year 2021)

Elsa, Dolly, Jeanie, Vince, Titch and Bailey savour seaside smells at Reculver Towers and Roman Fort, Kent, United Kingdom on February 23, 2021. The southeast of England will be warm again. (Photo by Liz Gregg/Triangle News)

Customers are seen in front of a shop that reopened in central Copenhagen, Denmark, 01 March 2021. Shops reopened after several months of closure due to the coronavirus COVID-19 pandemic. (Photo by Philip Davali/EPA/EFE)