Ranger trainees and trainee dogs simulate an ambush against rhino poachers at the Paramount Group Anti-Poaching training and K9 (canine) academy on November 26, 2014 in Magaliesberg, South Africa. One of the largest of its kind in Africa, the Academy will address the ever increasing need for training of Conservation Officers in anti poaching activities, wildlife contraband detection, specialist K9 solutions and Ranger K9 handler training – all of which have proven success rates in combatting and apprehending poachers and their activities. (Photo by Gianluigi Guercia/AFP Photo)

Young monks laugh at their own photos taken by a German photojournalist in the main courtyard of the Dzong on October 13, 2011 in Punakha, Bhutan. King Jigme Khesar Namgyel Wangchuck, 31 and Queen of Bhutan Ashi Jetsun Pema Wangchuck, 21 wed in Bhutan's historic 17th century Punakha Dzong the same venue that hosted the King's historical coronation ceremony in 2008. (Photo by Triston Yeo/Getty Images)

Groupama Sailing Team, skippered by Franck Cammas of France during leg 1 of the Volvo Ocean Race to Cape Town on November 6, 2011. (Photo by Yann Riou/Groupama Sailing Team/Volvo Ocean Race via Getty Images)

A member of the German wireless police picks up signals on the radio equipment he carries on his back, while his colleague takes notes. (Photo by General Photographic Agency/Getty Images). Circa 1925

A handout picture provided by Global newsroom of Czech Martin Sonka (C) leading Nigel Lamb (top) of Great Britain and Yoshihide Muroya of Japan (down) along the Mount Fuji prior the third stage of the Red Bull Air Race World Championship in Chiba, Japan on June 1, 2016. (Photo by Predrag Vockovic/EPA/Global Newsroom)

United States' Inika McPherson prepares an attempt during the women' s high jump final during the World Athletics Championships in London Saturday, August 12, 2017. (Photo by Kai Pfaffenbach/Reuters)

A graffiti, portraying a woman, is seen in Medellin, Colombia on November 19, 2017. Mural graffitis from different artists, street art can be seen in almost every city on Earth, but street arts raw power and potential for change was felt by me most intensively in Medellins Comuna 13, previously one of Colombias most dangerous neighbourhoods, in fact Communa 13 was constant battleground between gangs, narcos, paramilitaries and the government, but today you would hardly recognise it. (Photo by Juancho Torres/Anadolu Agency/Getty Images)

A woman stumbes as people run down Oxford Street, London, Britain, November 24, 2017. Police are responding to reports of an incident at London's Oxford Circus Tube station and have urged the public to avoid the area. (Photo by Peter Nicholls/Reuters)