A girl catches a fish in the marshes of the southern district of Chibayish in Dhi Qar province, about 120 kilometres northwest of the southern city of Basra, on September 23, 2020. Iraq's southern marshes are blossoming thanks to a wave of ecotourists picnicking and paddling down their replenished river bends. (Photo by Hussein Faleh/AFP 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)

An Ethiopian refugee who fled Tigray region, stands within the Fashaga camp on the Sudan-Ethiopia border, in Kassala state, Sudan on December 13, 2020. (Photo by Mohamed Nureldin Abdallah/Reuters)

A man dressed in Christmas garb smokes a hand-rolled cigarette, Thursday, December 24, 2020, in Times Square on Christmas Eve in New York. (Photo by Kathy Willens/AP Photo)

A young girl from the Makonde ethnic group wearing earth makeup on her facen, a beauty symbol, carries a baby on her back as she poses for pictures in the community of Marupa, a relocation center for internally displaced families in the Chiure district, on February 23, 2021. Thousands of families from different districts of the Cabo Delgado province who have been displaced have been located by the government in different areas of the province. (Photo by Alfredo Zuniga/AFP Photo)

Taras Mychalewych, 75, poses for a portrait with his vaccination card after receiving his coronavirus disease (COVID-19) vaccine at a rural vaccination site in Columbus, New Mexico, U.S., April 16, 2021. (Photo by Paul Ratje/Reuters)

An empty cell block is pictured within Joint Task Force Guantanamo's Camp VI at the U.S. Naval Base in Guantanamo Bay, Cuba March 22, 2016. (Photo by Lucas Jackson/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)