Racegoers try to shelter from the rain during day one of the Cazoo Derby Festival at Epsom Racecourse in Surrey, United Kingdom on Friday, June 4, 2021. (Photo by John Walton/PA Images via Getty Images)

This photograph taken during a government organised media tour shows people in traditional costume standing in Potala Palace Square as the Potala Palace – classified as a World Heritage Site by Unesco in 1994 – is seen in the background in the regional capital Lhasa, in China's Tibet Autonomous Region, on June 1, 2021. (Photo by Hector Retamal/AFP Photo)

An illuminated Christmas tree leans against the window of a damaged house in Mayschoss in the Ahrtal valley, southern Germany, Tuesday, December 14, 2021. The region was hit by floodings exactly five months ago, causing the death of about 180 people. Amid the mud and debris still clogging the streets from last summer's devastating floods, residents of the Ahr Valley in western Germany are trying to spark some festive cheer with Christmas trees. (Photo by Michael Probst/AP Photo)

A jogger runs on the bank of Donaukanal channel in central Vienna, Austria, September 5, 2016. (Photo by Heinz-Peter Bader/Reuters)

A fuel cell electric vehicle (FCEV) by Nissan is shown at China (Guangzhou) International Automobile Exhibition in Guangzhou, China November 18, 2016. (Photo by Bobby Yip/Reuters)

This picture taken on May 21, 2016 shows professional wrestlers fighting each other during the Wrestling City Asia organized by Singapore Pro Wrestling at a stadium in Kuala Lumpur. Kenneth Thexeira is a mild-mannered writer for an interior-design magazine by day, but on certain nights his alter ego bursts forth in golden tights and a baby-blue cape: enter “The Eurasian Dragon”. (Photo by Mohd Rasfan/AFP 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)

Enthusiasts gathered at Cad East in Snowdonia National Park, England to take pictures of F-15 Eagle fighters as they completed the Mach Loop, November 2017. (Photo by Caters News Agency)