A Siberian tiger at a photographer for getting too much in its face during the presentation of two new Siberian tigers at Cabarceno Natural Reserve in Cabarceno, northern Spain, 21 July 2014. (Photo by Pedro Puente Hoyos/EPA)

Beryl Lipton, left, douses Matt Lee during the ice bucket challenge at Boston's Copley Square, Thursday, August 7, 2014 to raise funds and awareness for ALS. The idea is: pay up for charity or get doused. The fund-raising phenomenon is catching on fast, propelled by popular videos of the dunkers and the dunked – including famous athletes and entertainers – posted on social media sites. And the challenges are raising tens of thousands of dollars and immeasurable awareness for causes from ALS to breast cancer to a camp for kids who've lost a father to war. (Photo by Elise Amendola/AP Photo)

“Warming up”. This photo I capture in the early afternoon, the animal species of lemurs fly. Photo location: Sambas, West Kalimantan, Indonesia. (Photo and caption by Hendy Mp/National Geographic Photo Contest)

A competitor shows her tattoos at the MBK Tattoo Contest in a shopping mall in Bangkok October 23, 2014. (Photo by Athit Perawongmetha/Reuters)

A camel yawns as a tourist checks images on her camera following a ride on a camel safari alongside the Pacific Ocean on Lighthouse Beach, north of Sydney, December 4, 2014. For 25 years camel rides on this beach have given visitors to Australia's holiday coast a rare experience available only in a handful of locations in the country. Australia's long history with the “ships of the desert” goes back to the 1800s when they were imported from Afghanistan and India for use as transportation across Australia's vast deserts before being released into the wild following their replacement by motorised transport. (Photo by Jason Reed/Reuters)

“Zeybeks”. That's Dance, Sunward and Zeybeks. (Photo by Hasan Baglar/2014 Sony World Photography Awards)

Water is seen on part of the glacial ice sheet that covers about 80 percent of the country is seen on July 17, 2013 on the Glacial Ice Sheet, Greenland. As the sea levels around the globe rise, researchers affilitated with the National Science Foundation and other organizations are studying the phenomena of the melting glaciers and its long-term ramifications. The warmer temperatures that have had an effect on the glaciers in Greenland also have altered the ways in which the local populace farm, fish, hunt and even travel across land. In recent years, sea level rise in places such as Miami Beach has led to increased street flooding and prompted leaders such as New York City Mayor Michael Bloomberg to propose a $19.5 billion plan to boost the citys capacity to withstand future extreme weather events by, among other things, devising mechanisms to withstand flooding. (Photo by Joe Raedle)

A protesting student runs past a burning bus off campus outside the University of the Witwatersrand in Johannesburg, South Africa on Monday, October 10, 2016. Tear gas and water cannon were fired as hundreds of students protested at the university amid a bitter national dispute with university managers and the government over demonstrators' demands for free education, forcing student into the neighbouring city streets. (Photo by AP Photo)