An ice swimming enthusiast dressed as Neptune takes to the frigid waters of Orankesee lake during the 27th annual "Winter Swimming in Berlin" on January 8, 2011 in Berlin, Germany. A local swimmers' group called the “Berlin Seals” invite ice swimmers from across Germany and abroad to the annual event. Members claim ice swimming is good for the body's blood circulation. (Photo by Sean Gallup)

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)

Rescuers attempt attempt to push stranded whales back into the ocean at Ujong Kareng beach in Aceh province, Indonesia, Monday, November 13, 2017. An official said a small pod of whales was stranded at the beach and attracted hundreds of onlookers who posed for pictures with them. (Photo by AP Photo/Zulkarnaini)

A massive, 8 metre tall sculpture of Marilyn Monroe, frozen with her dress blowing up, was on display at a shopping mall in downtown Dalian city, northeast China's Liaoning province, on Tuesday, November 14, 2017. The sculpture is a replica of Seward Johnson's Forever Marilyn in Chicago. (Photo by Imagine China/Rex Features/Shutterstock)

Drag queen Courtney Act (real name Shane Jenek) attends the Celebrity Big Brother male contestants launch night at Elstree Studios on January 5, 2018 in Borehamwood, England. The drag queen was left over-exposed on last show after her outfit apparently fell off. (Photo by Mike Marsland/WireImage)

Members of the Mayossa folk dance group pour water on a young woman in Kiskunmajsa, Hungary on April 2, 2018. According to an old Hungarian tradition, celebrated for several hundred years, young men pour water on young women, who in exchange present their sprinklers with beautifully colored eggs on Easter Monday. (Photo by Sandor Ujvari/EPA/EFE/Rex Features/Shutterstock)

A keeper feeds a four-week-old jaguar while presenting it to the media, at a zoo in Ciudad Juarez, Mexico, October 14, 2015. (Photo by Jose Luis Gonzalez/Reuters)

Ferrari driver Fabio Barone and his Ferrari 458 Italia competes against a Roman chariot drawn by two horses on “Ben Hur” movie set at Cinecitta World amusement park on May 11, 2017 in Castel Romano near Rome. (Photo by Andreas Solaro/AFP Photo)