A groom leads his horse in the equine pool after working out on the track, during early morning workouts for the upcoming Derby race in Mumbai January 29, 2015. (Photo by Danish Siddiqui/Reuters)

Caporal dancers perform during the carnival celebrations in Oruro, Bolivia, Saturday February 14, 2015. The Carnival of Oruro which is a religious festival dating back more than 2000 years in an ongoing pagan-catholic blend of religious practice in the region, and is one of UNESCO's Masterpieces of the Oral and Intangible Heritage of Humanity. (Photo by Juan Karita/AP Photo)

Bison along the Bitterroot Valley's Eastside Highway north of Stevensville, Montana, are covered in snow following a blizzard on November 23, 2010. (Photo by Perry Backus/The Missoulian)

A vendor (C) cuts slaughtered dogs for sale at his roadside stall in Duong Noi village, outside Hanoi December 16, 2011. While animal rights activists have condemned eating dog meat as cruel treatment of the animals, it is still an accepted popular delicacy for some Vietnamese, as well in some other Asian countries. Duong Noi is well-known as a dog-meat village, where hundreds of dogs are killed each day for sale as popular traditional food. Dog-eating as a custom is rooted in Vietnam and was developed as a result of poverty. One kilogram of dog meat costs about 130,000 dongs ($6.2). (Photo by Reuters/Kham)

A racegoer uses the camera on her phone to check her hair on the opening day of the Grand National Festival at Aintree Racecourse on April 3, 2014 in Aintree, England. The three days of racing attracts thousands of racegoers and fans from across the world. The meeting culminates with millions of pounds being wagered on the runners taking part in Europe's richest jump race, the Grand National. (Photo by Christopher Furlong/Getty Images)

Employees of a food stand take pictures of Titan, a robot created by England Cyberstein Robots, performing at the Danilovsly market in downtown of Moscow, Russia, 12 May 2014. Titan visited to Moscow to attend “Bal Robotov”, an interactive exhibition of the most recent advances in robotics which will be opened on 15 May in Artplay Moscow exhibition center. Titan worked alongside superstars including Will.i.am, Rihanna, Will Smith and Jackie Chan. (Photo by Sergei Ilnitsky/EPA)

A man from Dinka tribe holds his AK-47 rifle in front of cows in a Dinka cattle herders camp near Rumbek, capital of the Lakes State in central South Sudan December 14, 2013. (Photo by Goran Tomasevic/Reuters)

A woman jumps as a friend (not seen) takes a photo in front of a large drawing of Pope Francis depicting him as a superhero near the Vatican January 29, 2014. The Argentinian Pope is shown taking off into air with his right fist clenched in a classic Superman style. (Photo by Alessandro Bianchi/Reuters)