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)

Shepherd brothers Mustafa Erbay and Baran Erbay train their camels on snowy grounds, enabling them to become champions in competitions held in the Aegean and Mediterranean regions in Baskale district of Van, Turkey on February 1, 2020. (Photo by Ozkan Bilgin/Anadolu Agency via Getty Images)

People wearing mushroom hats stand in front of the Washington Monument in Washington, D.C., U.S., May 14, 2021. (Photo by Andrew Kelly/Reuters)

A leopard attacks a forest guard at Prakash Nagar village near Salugara on the outskirts of Siliguri on July 19, 2011. Six people were mauled by the leopard after the feline strayed into the village area before it was caught by forestry department officials. Forest officials made several attempt to tranquilised the full grown leopard that was wandering through a part of the densely populated city when curious crowds startled the animal, a wildlife official said. (Photo by Diptendu Dutta/AFP Photo)

NHRA top fuel driver Spencer Massey explodes the engine of his dragster on fire during the Thunder Valley Nationals at Bristol Dragway on October 17, 2021. Massey was unhurt in the incident. (Photo by Mark J. Rebilas/USA TODAY Sports)

A woman looks at The Empire State Building and the New York Skyline during a preview of SUMMIT One Vanderbilt observation deck, which is spread across the top four floors of the new One Vanderbilt tower in Midtown Manhattan, in New York City, New York, U.S., October 18, 2021. (Photo by Eduardo Munoz/Reuters)

A robot used to assist Covid-19 patients is seen in an elevator on December 5, 2020 in New Delhi, India. The “Mitra” robot can connect patients with their loved ones, and can assist healthcare workers on the frontlines of the pandemic by minimisng the risk of infections caused by close contact. The Yatharth Hospital, which is treating Covid-19 patients in Noida, on the outskirts of New Delhi, is one of a handful of hospitals in India that has started to use robots. (Photo by Anindito Mukherjee/Getty Images)

A woman walks up a stairway painted in the rainbow colors in Bucharest, Romania, Saturday, July 11, 2020. Romania reported 698 new COVID-19 infections in the last 24 hours, the highest level since the pandemic reached the country in February. (Photo by Vadim Ghirda/AP Photo)