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)

People fancy dressed as “Catrina” take part in the “Catrinas Parade” along Reforma Avenue, in Mexico City on October 22, 2017. Mexicans get ready to celebrate the Day of the Dead highlighting the character of La Catrina which was created by cartoonist Jose Guadalupe Posada, famous for his drawings of typical local, folkloric scenes, socio- political criticism and for his illustrations of “skeletons” or skulls, including La Catrina. (Photo by Ronaldo Schemidt/AFP Photo)

American actress Paris Jackson pulls faces at photographers during the “Melbourne Cup” race day festivities in Melbourne, Australia on November 7, 2017. (Photo by Media-Mode/Splash News and Pictures)

Charles Manson plays up to the camera during a 1988 interview with reporter Geraldo Rivera at San Quentin prison in 1988. Authorities say Manson, cult leader and mastermind behind 1969 deaths of actress Sharon Tate and several others, died on Sunday, November 19, 2017. He was 83. (Photo by AP Photo)

Bella Hadid is close to losing her top while on location for a photoshoot in Brooklyn, New York on December 11, 2017. (Photo by NPEx/Splash News and Pictures)

A Pakistani vendor prepares peanuts for sale on a roadside in Peshawar, Pakistan, 01 January 2018. After a good raining season the sales of dry fruits flourish in the country. Tourists from all over Pakistan come to Peshawar to purchase dry fruits along with other items because of price differences between different parts of the country. (Photo by Bilawal Arbab/EPA/EFE)

Performers Roni, Liv and Becky behind the scenes at Great Yarmouth Hippodrome Circus, England. (Photo by Nick Warner/The Guardian)

A monkey leaps into a pond on a hot day in Allahabad on May 19, 2017. According to local reports temperatures have soared in the northern Indian city to 47.28 Celsius. (Photo by Sanjay Kanojia/AFP Photo)