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)

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)

Women dancing at the disco club Xenon in New York City, USA in 1978. Xenon was a popular disco in Manhattan in the late 1970s and early 1980s. It was the only nightclub popular enough to compete with Studio 54. (Photo by Waring Abbott/Getty Images)

A seafood vendor moves a giant swordfish to his stall at a market in Qingdao, Shandong province, China, September 12, 2015. The 4.1-metre-long (13.5 feet) swordfish, weighed about 309.5 kilograms (682 lbs), was caught by local fishermen on Friday, local media reported. (Photo by Reuters/Stringer)

Sulphur miners haul sulphur up an arduous path out of Indonesia’s Ijen volcano. The average carry out of the volcano is 70 kilograms per load per miner. The all-time record carry was 120 kilograms in one load. Extraordinary numbers given most of the miners only weigh around 55 kilograms. Ijen volcano, Indonesia, 2012. (Photo by Hugh Brown/South West News Service)

Cambridge policemen, known as “Bulldogs”, lined up for the University Bulldogs Chase, dressed in morning coats and top hats, 7th March 1936. (Photo by H. Allen/Topical Press Agency/Getty Images)

Woman dons a mask a she prepares to dance in the streets during the feast of La Diablada, in Pillaro, Ecuador, Friday, January 4, 2019. The town of Pillaro kicks off the feast of the La Diablada with neighborhoods competing to bring as many people dressed as different characters. (Photo by Dolores Ochoa/AP Photo)

PETA (People for the Ethical Treatment of Animals) activists protest in front of the venue during the Berlin Fashion Week Autumn/Winter 2019/20 in Berlin, Germany, January 15, 2019. (Photo by Fabrizio Bensch/Reuters)