A couple takes a selfie as Hoa Binh hydroelectric power plant opens the flood gates after a heavy rainfall caused by Talas typhoon in Hoa Binh province, outside Hanoi, Vietnam July 20, 2017. (Photo by Reuters/Kham)

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)

Anissa Barbato from New York looks out over the city from the Edge, the highest outdoor sky deck in the Western Hemisphere on September 2, 2020 as it reopened to the public in New York. Rising 1,131 feet in the air from the heart of Hudson Yards it offers 360-degree views of New York Citys iconic skyline from the 100th floor outdoor viewing. (Photo by Timothy A. Clary/AFP Photo)

Social distancing signs are pictured as models wear protective face masks before the show of designer Andres Sarda during the Mercedes Benz Fashion Week amid the coronavirus disease (COVID-19) outbreak in Madrid, Spain, September 10, 2020. (Photo by Sergio Perez/Reuters)

Police officers look on as protesters block the road with burning tyres and wood, during a mass protest the morning after preliminary results were released for five communes in Conakry on October 21, 2020. African monitors said on October 20, 2020, that Guinea's weekend election was conducted properly, but the political opposition to incumbent Alpha Conde, which has already claimed victory, dismissed it as fraudulent. (Photo by John Wessels/AFP Photo)

Mahmoud El Komy, a 26-year-old Egyptian mechatronics engineer, stands beside Cira 3, a remote-controlled robot that runs tests on suspected coronavirus disease (COVID-19) patients, to limit the human exposure to the virus, amid a second wave of infections in Tanta, Egypt, November 18, 2020. (Photo by Mohamed Abd El Ghany/Reuters)

In this Thursday, June 14, 2018, file photo, students wear virtual reality goggles during a science class at Pyongyang Teachers' University, a teacher training college, in Pyongyang, North Korea. (Photo by Dita Alangkara/AP Photo)

In this undated photo released Tuesday April 13, 2021, by Russian Defense Ministry Press Service, A Tu-160 strategic bomber of the Russian air force is shown on a training mission somewhere in Russia. Russian Defense Minister Sergei Shoigu on Tuesday described a massive military buildup in western Russia as part of drills intended to check the armed forces' readiness amid the threats posed by NATO. (Photo by Vadim Savitsky/Russian Defense Ministry Press Service via AP Photo)