An urban fox walks alongside the Mall in central London, Britain, November 29, 2016. (Photo by Toby Melville/Reuters)

An alpaca is seen near the Inca citadel of Machu Picchu in Cusco December 2, 2014. Machu Picchu, a UNESCO World Heritage Site, is Peru's top tourist attraction, with the government limiting tourists to 2,500 per day due to safety reasons and concerns over the preservation of the ruins. (Photo by Enrique Castro-Mendivil/Reuters)

A worker walks through a salt pan on the eve of May Day or Labour Day on the outskirts of the southern Indian city of Chennai April 30, 2014. India is the third largest salt producing country in the world after China and U.S. with global annual production about 230 million tonnes, according to government data. (Photo by Reuters/Babu)

A rescue helicopter is shown at the Mount Everest south base camp in Nepal a day after a huge earthquake-caused avalanche killed at least 17 people, in this photo courtesy of 6summitschallenge.com taken on April 26, 2015 and released on April 27, 2015. Rescue teams, helped by clear weather, used helicopters to airlift scores of people stranded at higher altitudes, two at a time. (Photo by Reuters/6summitschallenge.com)

A Filipino dancer performs with fire to mark the Chinese Lunar New Year in Manila's Chinatown, Philippines, 28 January 2017. Chinese around the world celebrate the Lunar New Year on 28 January 2017, the first day of the year of rooster. (Photo by Francis R. Malasig/EPA)

A woman surveys the damage after the earthquake on March 17, 2011 in Kensennuma, Japan. Residents were allowed back to their homes today and began the massive cleanup operation caused by a 9.0 magnitude strong earthquake that struck on March 11 off the coast of north-eastern Japan. The quake triggered a tsunami wave of up to 10 metres which engulfed large parts of north-eastern Japan. The death toll has risen past 5000 with at least 8600 people still missing. (Photo by Chris McGrath/Getty Images)

Stunning images taken by Sean Lenz, 19, and Kristoffer Abligaard, 20, show picturesque waterfalls transformed into vibrant rainbows of colour. The awe-inspiring images were created by clever use of long exposure photography and glow sticks floating through water. Photo: Picturesque waterfalls transformed into rainbows of colour. (Photo by Sean Lenz/Kristoffer Abildgaard)

A goose has terrorized students at the University of Warwick, Coventry, UK, on May 22, 2013. The bird built its nest near a block of student apartments and attacks anyone who goes near the nest. (Photo by Caters News/The Grosby Group)