Star trails form over the Memorial House of the Bulgarian Communist Party on mount Buzludzha in this long exposure picture taken on September 12, 2014. The monument was officially opened in 1981 by the Bulgarian Communist regime to mark 100 years of the set up of an organised Socialist movement, a predecessor of the Bulgarian Communist Party. The monument, no longer maintained by the Bulgarian government after the fall of the Communist regime in 1989, is now abandoned and vandalized. (Photo by Stoyan Nenov/Reuters)

Indian authorities hold a tiger skin as they set fire to a stockpile of illegal wildlife parts at the Delhi Zoo in New Delhi, India, Sunday, November 2, 2014. A stockpile of tiger skins, elephant tusks, rhino horns and other illegal animal parts were burned Sunday in an effort to discourage wildlife smuggling in South Asia. (Photo by Tsering Topgyal/AP Photo)

Workers from the South Florida Science Center and Aquarium and Imagine Exhibitions put together an animatronic spinosaurus outside the science center in West Palm Beach, Fla., Tuesday, October 27, 2015. The giant spinosaurus is part of the Dinosaurs Around the World exhibit, set to open on November 1. (Photo by Maria Lorenzino/South Florida Sun-Sentinel via AP Photo)

The rotating updraft base of a supercell thunderstorm, and a rear flank downdraft containing rain and hail, backlit by the setting sun, on May 10, 2014, in Climax, Kansas, United States. To most of us, dark clouds on the horizon usually means rain – but here in Kansas, they can also signal the start of a supercell. The huge formations, also known as rotating thunderstorms, are among the most powerful weather phenomenon found over land. They can occur anywhere where the conditions are right, but are normally found in more arid climates. These awe-inspiring supercells were captured south of Climax city by storm chaser Stephen Locke. (Photo by Stephen Locke/Barcroft Media)

A former Gurkha (special forces soldier), Nirmal Purja, takes a selfie at the start of his attempt to scale the world’s 14 highest peaks in seven months to break a 31-year-old record. Nirmal Purja, known as Nims, aims to smash the current record – which stands at seven years, 11 months and 14 days – set by Polish climber Jerzy Kukuczka. On the way, he also plans to defeat at least seven speed world records on mountains over 8,000m high. (Photo by Nirmal Purja/PA Wire Press Association)

A dog swims as a resident navigates his boat in a neighbourhood flooded by the Purus river, which continues to rise from days of heavy rainfall in the region, in Boca do Acre, Amazonas state March 14, 2015. According the state civil defense, more than 20,000 people have been left homeless along the Purus river, where incessant rains have flooded the area and caused the river to burst their banks. (Photo by Bruno Kelly/Reuters)

A man carries a dog and wades through a flooded street in Chennai, in the southern Indian state of Tamil Nadu, Wednesday, December 2, 2015. Weeks of torrential rains have forced the airport in the state capital Chennai to close and have cut off several roads and highways, leaving tens of thousands of people stranded in their homes, government officials said Wednesday. (Photo by AP Photo)

In this November 17, 2014 photo, Pancho, a domesticated huitia, confronts a camera, in Bainoa, Cuba. With their rope-like, dark tails, long front teeth, and whiskers that appear to be vibrating, huitias look like giant rats. They measure nearly a foot long (about 30 centimeters), with the largest ones weighing in bigger than a small dog. (Photo by Ramon Espinosa/AP Photo)