A passenger aircraft passes over a residential house as it prepares to land at London Heathrow Airport in west London on October 17, 2016. Britain's government is considering whether to approve a third runway at Heathrow or expand air capacity in southeast England at another airport such as London Gatwick. (Photo by Daniel Leal-Olivas/AFP Photo)

Mahouts return home with their elephants carrying grass to feed them on the eve of the rhino census in Kaziranga National Park in Assam state, India, 24 March 2015. Kaziranga will be closed to visitors for the next two days for a census of the rhinos commencing 25 March, in a previous census in 2013 in the park the population of the Indian rhinos was 2329. (Photo by EPA/Stringer)

A Saudi soldier fires a mortar towards Houthi movement position, at the Saudi border with Yemen April 21, 2015. (Photo by Reuters/Stringer)

A man cries in a graveyard during the funeral of Nasser Ali Afglio, a young Libyan rebel killed during battle with government troops loyal to Libyan ruler Moammar Gaddafi April 19, 2011 in Misrata, Libya. The graveyard where Nasser was buried has hundreds of simple concrete graves; many dozens are those that have been killed during the last two months of fighting in the besieged town. Thousands of civilians are trapped in Misrata as fighting continues between Libyan government forces that have surrounded the city and anti-government rebels there. (Photo by Chris Hondros/Getty Images)

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)

A resident jumps as he watches strong waves crash into shore as an effect of Typhoon Hagupit in Legazpi, Albay province, eastern Philippines on Sunday, December 7, 2014. Typhoon Hagupit knocked out power in entire coastal provinces, mowed down trees and sent more than 650,000 people into shelters before it weakened Sunday, sparing the central Philippines a repetition of unprecedented devastation by last year's storm. (Photo by Aaron Favila/AP Photo)

Visitors to the annual Vivid Sydney light festival wear matching illuminated suits alongside the Sydney Harbour Bridge on the second night of the light and sound show in Sydney, Australia, May 28, 2016. (Photo by Jason Reed/Reuters)

In a photo taken on November 27, 2016 a female traffic police officer directs traffic on a road in Pyongyang. Believed to be hand-picked for their looks, Pyongyang's female traffic police are a familiar sight at intersections around the capital, where traffic volumes have noticeably increased in recent years. (Photo by Ed Jones/AFP Photo)