In this photograph taken on February 18, 2016, Pakistani children ride on swings in the predominantly Pashtun Korangi District of Karachi. In a rundown district of Karachi, Rabia balks at a neighbour's proposal to vaccinate her children, demonstrating one of the biggest hurdles to eradicating polio in Pakistan by the end of the year: confused and frightened parents. (Photo by Asif Hassan/AFP Photo)

A woman takes a selfie picture as Turkish Kurds gather as part of Newroz celebrations in Diyarbakir, on March 21, 2016. Nowruz, the Farsi-language word for “New Year”, is an ancient Persian festival, celebrated on the first day of spring, on March 21, in Central Asian republics, Iraq, Turkey, Afghanistan and Iran. (Photo by Ilyas Akengin/AFP Photo)

A girl calls to her mom as she stands near a dead whale on the shore Monday morning, April 25, 2016, on the cobblestone beach at Lower Trestles on San Onofre State Beach, just south of San Clemente, Calif. (Photo by Jeff Gritchen/The Orange County Register via AP Photo)

Hanging bird cages are displayed on poles during a bird-singing contest in the Rueso district in Thailand's southern province of Narathiwat on March 23, 2014. Hundreds of bird owners from Thailand, Malaysia and Singapore took part in the traditional contest held every year. (Photo by Madaree Tohlala/AFP Photo)

People are seen in the crowd as Serbian Emir Kusturica & The No Smoking Orchestra performs during the third day of the Mexican musicial festival Vive Latino, at the Foro Sol in Mexico City, on March 29, 2014. (Photo by Alfredo Estrella/AFP Photo)

Two three-month-old female white Bengal tiger cubs play with a zoo keeper in their enclosure at the Buenos Aires' Zoo, in Argentina, on April 17, 2014. Captive white Bengal tiger Cloe, gave birth to three cubs – two females and one male – on January 14, 2014. (Photo by Juan Mabromata/AFP Photo)

Jimmy Bryan of Phoenix, Ariz., gets the checkered victory flag at the Indiana State Fairgrounds September 17, 1955 as he wins the “Hoosier Hundred” for the second consecutive year. Bryan averaged 83.98 miles an hour for the 100-lap, 100-mile AAA big car race. (Photo by AP Photo)

Alfred Yetta (L) and Kay Manning pose for a photo in front of a cardboard cut-out of Pope Francis, during an event organised by Christa Scalies, the co-creator of the Pop-Up Pope, in Fado Irish Pub & Restaurant in Philadelphia, Pennsylvania, September 16, 2015. (Photo by Mark Makela/Reuters)