Timbuktu: A UN peacekeeper from Burkina Faso stands guard at the Djinguereber mosque, built in the 14th century, during a visit by a UN delegation on election day in Timbuktu, Mali, July 28, 2013. (Photo by Joe Penney/Reuters)

Lindsay Mann (L) and Anabella Mowbray kiss as they take photos of themselves laying in the confetti on 7th Avenue in Times Square on New Year's Eve in New York January 1, 2015. (Photo by Carlo Allegri/Reuters)

A Russian-made rifle, carried by this woman when she was captured in Nearby Brush, is slung around her neck by South Vietnamese soldiers before they began their interrogation of her as Viet Cong suspect near AP La Ghi in Vietnam, August 25, 1965. The girl behind the woman, also was captured in the brush. (Photo by AP Photo)

A navy diver storms into the gallery during a military display at Singapore's 52nd National Day celebrations at Marina Bay in Singapore August 9, 2017. (Photo by Edgar Su/Reuters)

A competitor poses on the catwalk during the Miss Bumbum Brazil 2016 pageant in Sao Paulo, Brazil on November 9, 2016. Fifteen candidates compete in the annual pageant to select Brazil's sexiest female rear end. (Photo by Miguel Schincariol/AFP Photo)

A woman wearing a scarf to cover her face looks on as she waits for a passenger bus on a smoggy morning in New Delhi, India, November 8, 2017. The Great Smog of Delhi is an ongoing severe air-pollution event in New Delhi and adjoining areas in the National Capital Territory of India, in November 2017. Air pollution at this time peaked on both PM 2.5 and PM 10 levels. It has been reported as one of the worst levels of air quality in Delhi since 1999. (Photo by Saumya Khandelwal/Reuters)

Honourable mention, Behaviour category. Toss the scorpion – Indian roller playing with its kill by Susmita Datta. The image was taken during an early morning safari drive at Tadoba Andhari Tiger Reserve in India. (Photo by Susmita Datta/PA Wire/Royal Society Publishing Photography Competition 2017)

Rohingya refugee sisters Nur Kaida (R) and Ruhana hug each other at their shelter at the Palongkhali refugee camp near Cox's Bazar, Bangladesh December 21, 2017. (Photo by Marko Djurica/Reuters)