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)

Tens of millions of red crabs make their way across Christmas Island, Australia on November 13, 2021 during their annual migration from the forest to the ocean, swamping roads and bridges. (Photo by Parks Australia/Animal News Agency)

Coral grows in a sculpture at the MUSZIF underwater museum in Isla Fuerte, Bolivar department, Colombia, on May 22, 2024. In the Colombian Caribbean an underwater museum protects coral reefs threatened by tourism and climate change. (Photo by Luis Acosta/AFP Photo)

Puerto Rico's Grace Claxton warms up before competing in the Women's 400m Hurdles Round 1 during the athletics event at the Rio 2016 Olympic Games at the Olympic Stadium in Rio de Janeiro on August 15, 2016. (Photo by Jewel Samad/AFP Photo)

American Paralympic snowboarder Amy Purdy dances with a robot during the opening ceremony of the Rio 2016 Paralympic Games at the Maracana stadium in Rio de Janeiro on September 7, 2016. (Photo by Yasuyoshi Chiba/AFP Photo)

A Hindu devotee in a trance on their pilgrimage to the Batu Caves temple in Kuala Lumpur, Malaysia on January 28, 2018. Malaysian Hindu participate in the annual Hindu thanksgiving festival in which devotees subject themselves to painful rituals in a demonstration of faith and penance held in honour of Lord Murugan, Hindu in Malaysia celebrated Thaipusam begin on Jan 28 until 31 this year. (Photo by Aflo/Rex Features/Shutterstock)

Artist Jeff Koons sculpture Balloon Monkey (Magenta), 2006-13, with an estimate of £6,000,000-10,000,000 on display in St James's Square, London, before being sold by Christie's to raise funds for humanitarian aid for Ukraine. Picture date: Tuesday June 14, 2022. (Photo by Yui Mok/PA Images via Getty Images)

Israeli police officers are about to push away a demonstrator during a protest against Israel's Prime Minister Benjamin Netanyahu outside his residence in Jerusalem, Israel, early Sunday, August 9, 2020. (Photo by Ariel Schalit/AP Photo)