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)

A Sri Lankan leopard is pictured at a zoo in Dehiwala near Colombo on March 3, 2016, on World Wildlife Day. (Photo by Ishara S. Kodikara/AFP Photo)

Martin Lacey Jr. with a lion during the premiere of the Circus Krone program “Circus der Preistraeger” at Circus Krone on February 2, 2016 in Munich, Germany. (Photo by Hannes Magerstaedt/Getty Images)

U.S. Rep Steve Southerland grins after winning an auctioned possum during the Wausau Possum Festival on Saturday, August 2, 2014, in Wausau, Fla. What is usually a must-attend event for statewide candidates was notably lacking of them this year, perhaps because candidates who now raise tens of millions of dollars focus more on television ads than making personal contact. But not attending is a missed opportunity, said Susan MacManus, a University of South Florida political science professor who drove more than 350 miles for the festival. (Photo by Heather Leiphart/AP Photo/The News Herald)

Photographer Jim Zielinski from Florida, USA, captured this hilarious moment when a squirrel spied a tasty treat inside a novelty horse's head bird feeder in his back garden. (Photo by Jim Zielinski/Caters News)

Burning Man 2013. The federal government issued a permit for 68,000 people from all over the world to gather at the sold out festival, which is celebrating its 27th year, to spend a week in the remote desert cut off from much of the outside world to experience art, music and the unique community that develops. (Photo by Neil Girling)

Two Herens cows lock horns during the qualification round of the annual “Battle of the Queens” cow fight finals in Aproz, in the western Alpine canton of Valais May 5, 2013. Each year when taken to the alpine pastures, the cows test their strength and fight for the herd's leadership. The competition continues until a new queen has forced all the other cows to retreat. (Photo by Valentin Flauraud/Reuters)

Peru, Iquitos. Restaurant in Bellavista, an area by the Amazon on April 2005. (Photo by Jean-Claude Coutausse)