A Sumatran Tiger looks at visiting children from it's enclosure during the ZSL London Zoo's annual stocktake of animals on January 5, 2015 in London, England. The zoo's annual stocktake requires keepers to check on the numbers of every one of the 800 different animal species, including every invertebrate, bird, fish, mammal, reptile, and amphibian. (Photo by Dan Kitwood/Getty Images)

In this February 28, 2015 photo, teammates struggle to lift a bull off the trapped leg of a charro, during the bull riding event at a charreada in Mexico City. National Charros Association President Manuel Basurto Rojas said: “We in charreria are taking things into our own hands. We have codes, we have rules, for how to treat the animals. On the other hand, there is a lot of danger involved for the men doing these tricks”. (Photo by Rebecca Blackwell/AP Photo)

Children play football in Bujumbura, Burundi on March 19, 2015. (Photo by Carl de Souza/AFP Photo)

In this March, 2015 photo, a person sits at an upright piano that had been hauled up to Topanga Lookout in the Santa Monica Mountains in Calabasas, Calif. For a couple of days last week, a Southern California hilltop was alive with the sound of mystery. Hikers venturing to Topanga Lookout found a battered upright piano sitting on a graffiti-scrawled concrete slab with a panoramic view over the mountains between Calabasas and the Pacific Ocean. Turns out, the piano was used for a music video by Seattle-based artist Rachel Wong. The cinematographer, Michael Flotron, says he and four others used a dolly and rope to haul the 350-pound instrument a mile up the trail on Tuesday. After the shoot, it was too dark to get the piano back down. Flotron says people seem happy to leave it there. But if necessary, he'll haul the piano back down. (Photo by Michael Flotron/AP Photo)

Members of an American landing party assist troops whose landing craft was sunk by enemy fire off Omaha beach, near Colleville sur Mer, France, June 6, 1944. REUTERS/Weintraub/US National Archives

A man standing on the first cables during the construction of the Golden Gate Bridge with the Presidio and San Francisco in the background, San Francisco, California, 1935. (Photo by Underwood Archives/Getty Images)

Steve McCurry has been a photojournalist for over 30 years. He is the recipient of the Robert Capa Gold Medal, the National Press Photographers Award and four first prize awards in the World Press Photo contest. Photo: Afghanistan. (Photo by Steve McCurry)

Bikini-clad women sit as they operate a 3.6 metre-high custom-made female robot at the “Robot Restaurant” in Kabukicho, one of Tokyo's best known red light districts, August 15, 2012. (Photo by Tokyo Scum Brigade)