In this handout photograph received from the Delhi Police at the scene of the incident, an Indian schoolboy is confronted by a white tiger inside its enclosure at the Delhi Zoo in New Delhi on September 23, 2014. A white tiger on September 23 attacked and killed a schoolboy who appeared to have jumped or fallen into its enclosure at the zoo in the Indian capital, witnesses said. (Photo by AFP Photo/Delhi Police)

A biker rides in a “Ride for Pride” event to show support for the Confederate flag in Brandon, Hillsborough County, June 26, 2015. Several hundred people took part in the event. (Photo by Carlo Allegri/Reuters)

A gibbon drinks from a soft drink bottle, given by a tourist, at a zoo in Kunming, Yunnan province, June 18, 2015. (Photo by Wong Campion/Reuters)

In this January 27, 2015 photo, penguins walk on the shore of Bahia Almirantazgo in Antarctica. Antarctica “is big and it's changing and it affects the rest of the planet and we can't afford to ignore what's going on down there”, said David Vaughan, science director of the British Antarctic Survey. (Photo by Natacha Pisarenko/AP Photo)

A boy looks back while he and another boy play on a Syrian military tank, destroyed during fighting with the Rebels, in the Syrian town of Azaz, on the outskirts of Aleppo, Sunday, September 2, 2012. (Photo by Muhammed Muheisen/AP Photo)

Women porters load bundles onto their back for transport across the El Tarajal boarder separating Morocco and Spain's North African enclave of Ceuta, in Ceuta on December 4, 2014. Unemployment among Ceuta and Melilla's native workforce is more than 30 percent – among the highest rates in Spain. Meanwhile, authorities say some 30,000 Moroccan traders and menial workers cross into each territory every day. (Photo by Jorge Guerrero/AFP Photo)

A zoo employee carries three-month-old female giant panda cub, born to mother Liang Liang and father Xing Xing, on display to the public for the first time at the national zoo in Kuala Lumpur, Malaysia, November 17, 2015. (Photo by Olivia Harris/Reuters)

The 30th anniversary of the meltdown at the Chernobyl nuclear plant that caused large amounts of radioactive particles to be released into the air will be commemorated on April 26, 2016. Photojournalist Sean Gallup returned to the area to document the lasting effects of the world's worst nuclear power plant accident. Pictured, children's beds are seen in an abandoned kindergarten in Kopachi village located inside the Chernobyl exclusion zone, September 29, 2015, near Chernobyl, Ukraine. (Photo by Sean Gallup/Getty Images)