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)

Visitors watch as members of a local winter swimmers club pour buckets of cold water over their daughters, 7-year-old Liza Broverman and 2-year-old Alisa Smagina during a celebration of Polar Bear Day at the Royev Ruchey zoo, with the air temperature at about minus 5 degrees Celsius (23 degrees Fahrenheit), in Krasnoyarsk, Russia, November 27, 2016. (Photo by Ilya Naymushin/Reuters)

Five-month-old baby elephant Fah Jam swims during a hydrotherapy treatment as part of a lengthy rehabilitation process to heal her injured front left foot at a rehabilitation center in Pattaya, Thailand January 5, 2017. The baby elephant was injured at three months old when she got stuck in an animal snare put up by villagers to prevent elephant intrusions in Chanthaburi province. (Photo by Athit Perawongmetha/Reuters)

Four-year-old Etta Syrett relaxes on one of two giant pumpkins at Pinetops Nurseries in Lymington, UK on September 22, 2025, affectionately named “Dumbledore” and ”Muggle”. Grown by twins Ian and Stuart Paton, each weighs an estimated 1,179 kg (2,600 lbs). The 64-year-old brothers were inspired by Hagrid’s pumpkin patch in Harry Potter and hope to break the world record. (Photo by Ollie Thompson/Solent News & Photo Agency)

The Dora the Explorer balloon moves through Times Square during the Macy's Thanksgiving Day parade Thursday, November 23, 2006 in New York. (Photo by Frank Franklin II/AP Photo)

A man poses as “Lemongrab” from Adventure Time outside the MCM Comic Con at the Excel Centre in East London, October 25, 2014. (Photo by Andrew Winning/Reuters)

Australian singer/songwriter Delta Goodrem comes face-to-face for the first time with a wax figure of herself at Madame Tussauds in Sydney on April 11, 2012. Madame Tussauds, featuring wax doppelgangers of Dannii Minogue, Brad Pitt, Angelina Jolie, Johnny Depp and Lady Gaga, was officially open on April 16. (Photo by Ryan Pierse)

Cars float up from a car garage in a mixture of storm water and gasoline in lower Manhattan as workers begin the process of pumping out the mess. (Photo by Carolyn Cole/Los Angeles Times/MCT)