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)

Russian policemen detain a participant taking part in an unauthorized protest against Russia's partial military mobilization due to the conflict in Ukraine, in downtown of Moscow, Russia, 24 September 2022. Russian President Putin announced in a televised address to the nation on 21 September, that he signed a decree on partial mobilization in the Russian Federation. Russian citizens who are in the reserve will be called up for military service. On 24 February 2022 Russian troops entered the Ukrainian territory in what the Russian president declared a “Special Military Operation”, starting an armed conflict that has provoked destruction and a humanitarian crisis. (Photo by Maxim Shipenkov/EPA/EFE)

Russian policemen detain a person taking part in an unauthorized protest against Russia's partial military mobilization due to the conflict in Ukraine, in downtown Moscow, Russia on 24 September 2022. Russian President Putin announced in a televised address to the nation on 21 September, that he signed a decree on partial mobilization in the Russian Federation. Russian citizens who are in the reserve will be called up for military service. On 24 February 2022 Russian troops entered the Ukrainian territory in what the Russian president declared a “Special Military Operation”, starting an armed conflict that has provoked destruction and a humanitarian crisis. (Photo by Maxim Shipenkov/EPA/EFE)

A scene showing one of the first trench battles is prepared for the opening of the 3D Panorama exhibition “Memory talks. The road through war” in the former Sevcabel port in St. Petersburg, Russia, 16 September 2019. Various 3D dioramas – containing genuine wartime items such as aircraft, tanks and artillery in original size – allow visitors to walk through scenes from the beginning to the end of WWII without any museum barriers. The exhibition opens from 19 September 2019 to May 2020. (Photo by Anatoly Maltsev/EPA/EFE)

Actor George Clooney is arrested with his father Nick Clooney (2R) during a demonstration outside the Embassy of Sudan March 16, 2012 in Washington, DC. United to End Genocide, the Enough Campaign and Amnesty International held a rally to call on the United States and world leaders to stop the violence in South Sudan and prevent hundreds of thousands of people from starving. (Photo by Win McNamee/Getty Images)

Activists protesting cuts in subsidies to solar power in Germany protest outside the building where Vice Chancellor and Economy Minister Philipp Roesler and Environment Minister Norbert Roettgen were announcing the cuts on February 23, 2012 in Berlin, Germany. (Photo by Sean Gallup/Getty Images)

Actors wearing masks of Syrian President Bashar al-Assad and Russian Prime Minister Vladimir Putin perform with body bags during a demonstration outside United Nations headquarters on January 24, 2011 in New York City. Protesters called on the U.N. Security Council to pass a resolution to attempt to halt al-Assad's crackdown on the Syrian uprising. (Photo by Mario Tama/Getty Images)

A member of the pro-government “red shirt” movement attacks a Buddhist monk outside the National Anti-Corruption Commission office in Nonthaburi province, on the outskirts of Bangkok March 24, 2014. Members of the movement attacked the monk after he shouted complaints to the group blocking a road near the National Anti-Corruption Commission. (Photo by Chaiwat Subprasom/Reuters)