A handout photograph provided by Brian Kubicki of Costa Rican Amphibian Research Center on 26 April 2016 shows a “Crystal frog”, Hyalinobatrachium dianae (H. diane). This frog was discovered by US biologist Brian Kubicki and Costa Ricans Stanley Salazar and Robert Puschendorf in a rainy forest of Costa Rican caribbean after 40 years without notice of any new example of this kind. (Photo by Brian Kubicki/EPA/Costa Rican Amphibian Research Center)

In this timed-exposure night photo taken early on February 12, 2017, Mount Sinabung volcano spews reddish smoke and ash, as seen from the Karo district in North Sumatra province. Activity levels have increased in the past week, with Sinabung shooting hot ash clouds into the sky dozens of times, according to the local volcano monitoring agency. (Photo by AFP Photo/Stringer)

Contestant Nathalie De Oliveira of Brazil prepares backstage before the final show of the Miss International Queen 2016 transgender/transsexual beauty pageant in Pattaya, Thailand, March 10, 2017. Thai contestant Jiratchaya Sirimongkolnawin was crowned Miss International Queen 2016. The 2016 show was postponed from November last year due to Thailand's mourning period of its late King Bhumibol Adulyadej who died at age 88 on October 13, 2016. (Photo by Athit Perawongmetha/Reuters)

Graffiti is painted on the bathroom walls at a restaurant in the Williamsburg area of Brooklyn borough in New York, United States, October 1, 2015. Some 2.4 billion people around the world don't have access to decent sanitation and more than a billion are forced to defecate in the open, risking disease and other dangers, according to the United Nations. To mark World Toilet Day on November 19, Reuters photographers captured pictures of toilets in cities, towns and villages around the globe. (Photo by Shannon Stapleton/Reuters)

An officer reviews members of the honor guard as they line up before a welcoming ceremony for visiting Mozambique's President Filipe Jacinto Nyusi at the Great Hall of the People in Beijing, Wednesday, May 18, 2016. (Photo by Mark Schiefelbein/AP Photo)

People look at the Turrialba volcano as it spewes ashes on May 20, 2016, in Cartago, Costa Rica. The Turrialba volcano started erupting columns of smoke and ash that the wind extended towards the Costa Rican capital, in what according to experts is the strongest eruption in the past six years. (Photo by Ezequiel Becerra/AFP Photo)

A member of the Air Force's Wings of Blue Parachute Demonstration Team salutes as he jumps out of an aircraft, during the opening ceremony of Aviation Nation 2017 Nellis Air and Space Expo at Nellis Air Force Base, Nev., November 10, 2017. (Photo by Senior Airman Kevin Tanenbaum/Reuters/U.S. Air Force)

Tourists gather to watch Mount Agung at Amed beach in Karangasem on Indonesia' s resort island of Bali on November 30, 2017. Thousands of foreign tourists were expected to leave Bali by plane on November 30 following a nearly three- day airport shutdown sparked by a rumbling volcano on the Indonesian holiday island. (Photo by Juni Kriswanto/AFP Photo)