A Rohingya refugee child with thanaka paste is seen in Cox's Bazar, Bangladesh, July 4, 2018. (Photo by Mohammad Ponir Hossain/Reuters)

In this image made from video, woman protesters march with a sign outside the building housing the Saudi consulate in Sydney, Thursday, January 10, 2019. Four women held a topless protest in Sydney on Thursday to support runaway Saudi woman Rahaf Mohammed Alqunun, as Australia began considering her bid to settle in the country as a refugee. (Photo by Australia Broadcast Corporation via AP Photo)

The Duchess of Cambridge pulls a pint with the Duke of Cambridge during their visit to Belfast Empire Hall for an informal party to celebrate inspirational young people who are making a real difference in Northern Ireland as part of their two day visit to Northern Ireland on February 27, 2019. (Photo by Aaron Chown/PA Wire Press Association)

In this aerial photo taken on March 28, 2019 a hot air balloon flies over Putrajaya during the international hot air balloon festival in Putrajaya, Malaysia. (Photo by Mohd Rasfan/AFP Photo)

A public bus makes its way on a flooded road after heavy monsoon rains in Mumbai, India on August 4, 2019. India receives its monsoon rains from June to September. (Photo by Indranil Mukherjee/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)

Tactics reminiscent of the early American frontier days are now being used in Vietnam. Lieutenant Commander Donald D. Sheppard, UBN, of Coronado, California, aims a flaming arrow at a bamboo hut concealing a fortified Viet Cong bunker on the banks of the Bassac River, Vietnam on December 8, 1967. (Photo by AP Photo)

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