An elephant eats a snack after performing at Ringling Bros and Barnum & Bailey Circus' “Circus Extreme” show at the Mohegan Sun Arena at Casey Plaza in Wilkes-Barre, Pennsylvania, U.S., April 29, 2016. Elephants take a final bow at Ringling Bros and Barnum & Bailey Circus on Sunday, ending a 145-year spectacle that delighted fans but enraged animal activists, who say the highly publicized retirement is not enough. (Photo by Andrew Kelly/Reuters)

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)

A woman holds a champagne bottle during New Year's celebrations in Bucharest, Romania, Wednesday, January 1, 2014. Tens of thousands of Romanians took to the streets of the Romanian capital to join parties and watch fireworks. (Photo by Vadim Ghirda/AP Photo)

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)

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)

A new species of monkey found in the Democratic Republic of the Congo and identified as Lesula (Cercopithecus lomamiensis) is seen in this undated photograph from an article published September 12, 2012 in the science journal PLOS One. The monkey was first seen in 2007 by researchers John and Terese Hart of the Peabody Museum of Natural History at Yale Research Project. The finding of C. lomamiensis represents only the second new species of African monkey to be discovered in the past 28 years, according to the research article. (Photo by Hart J. A., Detwiler K. M., Gilbert C. C./Reuters)

A rescue helicopter is shown at the Mount Everest south base camp in Nepal a day after a huge earthquake-caused avalanche killed at least 17 people, in this photo courtesy of 6summitschallenge.com taken on April 26, 2015 and released on April 27, 2015. Rescue teams, helped by clear weather, used helicopters to airlift scores of people stranded at higher altitudes, two at a time. (Photo by Reuters/6summitschallenge.com)