A man crosses a mud-covered trail carrying his wife on his back at a flooded Han River park in Seoul, South Korea, August 4, 2020. (Photo by Kim Hong-Ji/Reuters)

Folk artists perform “iron flowers”, a folk art performance of throwing molten iron to create fireworks, in Daying County of Suining City, southwest China's Sichuan Province on January 26, 2023. (Photo by Xinhua News Agency/Rex Features/Shutterstock)

A Christian devotee participates in a re-enactment of the crucifixion of Jesus Christ on Good Friday in Chennai on April 7, 2023. (Photo by R.Satish Babu/AFP Photo)

A man carrying wall-clocks for sale walks along closed currency exchange shops, in Peshawar, Pakistan on September 12, 2023. (Photo by Fayaz Aziz/Reuters)

A model wears a creation as part of the Mugler Haute Couture Spring-Summer 2023 collection presented in Paris, Thursday, January 26, 2023. (Photo by Thibault Camus/AP Photo)

A cosplayer poses for a photograph during the Comic Market 90 (Comiket) event in Tokyo Big Sight on August 12, 2016, Tokyo, Japan. Many manga and anime fans wearing cosplay lined up in the sun for the first day of Comiket. Comiket was established in 1975 and focuses on manga, anime, gaming and cosplay. Organizers expect more than 500,000 visitors to attend this year's summer event which runs for three days until August 14. (Photo by Aflo/Splash News)

This undated handout picture made available on February 3, 2016 and provided by Russia's punk band Рussy Riot shows Рussy Riot frontwoman Nadezhda Tolokonnikova performing in the band's new music video titled “Chaika” in Moscow. Russian punk band Рussy Riot, which became a symbol of resistance for a church performance slamming President Vladimir Putin, released a new protest song on February 3 mocking a senior official for alleged corruption. Titled “Chaika”, the satirical song and accompanying video take aim at prosecutor general Yury Chaika, whose two sons have been accused of using their father's position to accrue large fortunes. (Photo by Andrey Noskov/AFP Photo/Russian Punk Band Рussy Riot)

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)