Policemen guard Poland's Supreme Court as a protester lies on the pavement in Warsaw, Poland, on Thursday, April 22, 2021. A disputed disciplinary body within Poland's Supreme Court is examining a motion that could result in the arrest of a judge who has become a symbol of the fight for an independent judiciary. (Photo by Czarek Sokolowski/AP Photo)

Tourists in traditional costumes visit a rose garden during a rose cultural festival on April 27, 2021 in Huzhou, Zhejiang Province of China. (Photo by VCG/VCG via Getty Images)

A Palestinian youth swings a homemade fireworks sparkler, as people celebrate on the night ahead of the Muslim holy fasting month of Ramadan, in Gaza City on April 11, 2021. (Photo by Majdi Fathi/NurPhoto/Rex Features/Shutterstock)

Members of the Moroccan Royal Armed Forces Rescue and Relief Unit take part in a biochemical simulation organized by the US Defense Threat Reduction Agency (DTRA) as part of the “African Lion” military exercise, in the port of Agadir, on June 15, 2021. (Photo by Fadel Senna/AFP Photo)

In this Saturday, June 24, 2017 file photo, Zeid Ali, 12, left, and Hodayfa Ali, 11, comfort each other after their house was hit and collapsed during fighting between Iraqi forces and Islamic State militants in Mosul, Iraq. The Ali cousins said some of their family members are still under the rubble. (Photo by Felipe Dana/AP Photo/File)

A fisherman struggles to push a wheelbarrow full of sharks that have just been dropped off a pirogue on the beach of Songolo, the fishing district of Pointe-Noire in the Republic of the Congo in November 2021. Many artisanal fishing crews on the Congolese coast specialise in shark fishing (Photo by Marco Simoncelli/Al Jazeera)

A protester is sprayed with mace by riot police after throwing a chair through a window of a business during the second night of demonstrations after a not guilty verdict in the murder trial of former St. Louis police officer Jason Stockley, charged with the 2011 shooting of Anthony Lamar Smith, who was black, in St. Louis, Missouri, U.S., September 16, 2017. (Photo by Lawrence Bryant/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)