Bjorn, aged 5, smiles as he poses with a Owl butterfly during an event to launch the Sensational Butterflies exhibition at the Natural History Museum in London, Britain March 23, 2016. The exhibition opens to the public on March 24 and runs until September 11. (Photo by Dylan Martinez/Reuters)

Dancers prepare before a performance in the backstage area of the Buick exhibition during the “Auto China 2014” Beijing International Automotive Exhibition in Beijing on April 21, 2014. Leading automakers have gathered in Beijing for the kickoff of China's biggest car show, but lackluster growth and environmental restrictions in the world's largest car market have thrown uncertainty into the mix. (Photo by AFP Photo)

A Republican farmer defending a farm on the outskirts of Irun against Nationalist forces during the Spanish Civil War, 6th September 1936. A comrade lies dead by his side. (Photo by Keystone/Hulton Archive/Getty Images)

A recruitment drive during the First World War at Trafalgar Square, London. (Photo by Central Press/Getty Images)

Men ride on a “mikoshi” or portable shrine as local people carry it into the sea during a festival to wish peace in the ocean and good fortune in the new year in Oiso, west of Tokyo, January 1, 2015. (Photo by Yuya Shino/Reuters)

“Hatem Moussa joined The Associated Press as a photojournalist in 1998. Since then, the Gaza City-based Moussa has covered repeated rounds of Israeli-Palestinian fighting in Gaza, including the wars of 2008-9, 2012 and 2014”. – Associated Press. Photo: A Palestinian youth jumps into the Mediterranean sea on the beach at the port of Gaza City, Gaza, Monday, August 27, 2012. (Photo by Hatem Moussa/AP Photo)

Sports Finalist – Ian MacNicol. Michalina Kwasniewska of Poland competes in the Women's high jump during day one of The European Athletics U23 Championships 2013 on July 11, 2013 in Tampere, Finland. (Photo by Ian MacNicol/Agence France-Presse)

A prisoner from the Pedrinhas prison is carried to receive medical help after he was injured during a fight between rival gangs inside the jail, in Sao Luiz, capital of Maranhao state, January 8, 2014. The recent posting on a major Brazilian news website of a video filmed last December 17 by Pedrinhas prisoners of the decapitated and tortured bodies of rival inmates inside the jail has highlighted some of the problems present in the country's prison system which houses nearly twice as many prisoners as its capacity, according to official statistics. (Photo by Douglas Cunha/Reuters/O Estado do Maranhão)