Refugees and migrants try to find a place on an already full train headed for Serbia, near the city of Gevgelija, The Former Yugoslav Republic of Macedonia, on February 24, 2016. Refugees and migrants from Iraq and Syria continue to pass through Macedonia on their way to the European Union. (Photo by Georgi Licovski/EPA)

Female of pygmy hippopotamus called Malaya from Netherlands in zoo in Dvur Kralove nad Labem, Czech Republic, February 22, 2016. (Photo by David Tanecek/CTK via ZUMA Press)

A museum employee views “Details of Renaissance Paintings (Sandro Botticelli, Birth of Venus, 1482)” by Andy Warhol at the Victoria and Albert museum in London, Britain, March 2, 2016. The piece forms part of “Botticelli Reimagined”, an exhibition exploring the ways artists have responded to the artistic legacy of the fifteenth century artist Sandro Botticelli, and including over fifty artworks by Botticelli himself. (Photo by Toby Melville/Reuters)

Female Siberian tiger Dasha yawns in the new enclosure at the zoo in Duisburg, Germany, 30 March 2016. The new facility is three times larger than the old one and will be opened to the public on the same day. (Photo by Roland Weihrauch/EPA)

Actress Ruby Rose, left, recipient of the Stephen F. Kolzak Award, hands her jacket to presenter Taylor Swift during the 27th Annual GLAAD Media Awards at the Beverly Hilton on Saturday, April 2, 2016, in Beverly Hills, Calif. (Photo by Chris Pizzello/Invision/AP Photo)

A student protester throws a stone against a riot police vehicle during a demonstration to demand changes in the education system in Santiago, Chile, April 21, 2016. (Photo by Ivan Alvarado/Reuters)

Actress Shae Mitchell arrives at REVOLVE Desert House on April 16, 2016 in Thermal, California. (Photo by Ari Perilstein/Getty Images for A-OK Collective, LLC.)

Models wear creations from the Ronaldo Fraga collection during the Sao Paulo Fashion Week in Sao Paulo, Brazil, Monday, April 25, 2016. (Photo by Andre Penner/AP Photo)