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)

Most Russians intending to vote for Vladimir Putin in Sunday's election say stability is at the root of their faith in their candidate – though many young voters believe it's time for a change of leader. Putin, 65, is expected to win a fourth term in office with 69 percent of the vote, according to the latest survey by a state-run pollster. Reuters correspondents and photographers who travelled around the country talking to voters ahead of the March 18 election found nothing to contradict expectation of an emphatic Putin victory. (Photo by Anton Vaganov/Reuters)

German troops in Stalingrad, USSR. September 10, 1942. (Photo by TASS)

A raccoon scratches herself on the window sill of the Paige Donnelly Law Firm on the 23rd floor of the UBS Plaza building in St. Paul, Minnesota, U.S., June 12, 2018, in this image obtained from social media. (Photo by Evan Frost/MPR News via Reuters)

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)

A tamed hawk sits on a chair next to a participant during a traditional hunting contest in Almaty, Kazakhstan on December 1, 2018. (Photo by Pavel Mikheyev/Reuters)

Drag Queens set a Guinness World Record for the longest feather boa at 1.2 miles, along 42 St, in Times Square in New York, U.S., June 20, 2019. (Photo by Eduardo Munoz/Reuters)

This photo taken on February 26, 2019 shows an aerial view of a tea field in Zhangping in China's eastern Fujian province. (Photo by AFP Photo/China Stringer Network)