In this undated photo made available by journal Nature on January 15, 2014, a northern bald ibis (Geronticus eremita) flies in Tuscany, Italy. A new study released Wednesday, January 15, 2014 says the birds choreograph the flapping of their wings, getting a boost from an updraft of air in the wake of the flapping wings by flying behind the first bird and off to the side. When a flock of birds take advantage of these aerodynamics, they form a V. (Photo by Markus Unsöld/AP Photo)

Sri Lankan military personnel march during the country's 66th Independence Day celebrations in the central town of Kegalle, about 40 kms from the capital Colombo on February 4, 2014. Sri Lanka cemmemorates its independence from British rule on February 4, 1948. (Photo by Ishara S. Kodikara/AFP Photo)

Participants climb over a wall at the “Tough Mudder” endurance event series in Arnsberg September 6, 2014. Competitors who took part in the endurance event saw themselves having to overcome various military style obstacles. (Photo by Ina Fassbender/Reuters)

A rebel fighter carries his weapon as he moves through a hole in a wall in the old city of Aleppo near the frontline against forces loyal to Syria's President Bashar al-Assad December 28, 2014. (Photo by Jalal Al-Mamo/Reuters)

Emergency responders respond to the scene of a 565-foot-tall crane that toppled and flipped upside down, stretching along nearly two city blocks in downtown Manhattan in New York, February 5, 2016. The massive construction crane collapsed in lower Manhattan during a swirling snowstorm on Friday, killing one person and crushing a line of parked cars in the first accident of its kind in New York City since 2008. (Photo by Brendan McDermid/Reuters)

Roger Moore fights with Richard Kiel, as Jaws, who bites through a board in a scene from the film “The Spy Who Loved Me”, 1977. (Photo by United Artist/Getty Images)

A dead whale is seen on the shore of the Ipanema beach in Rio de Janeiro, Brazil November 15, 2017. A biologist, Rafael Carvalho, said on Wednesday the whale appeared to have been dead for a few days. Authorities were urging beachgoers who had flocked to Ipanema on a national holiday to stay away from the animal. However, many were spotted near the carcass with some people playing in the water nearby. The whale is approximately 39 feet (12 metres) long and weighs about 25 tonnes. (Photo by Pilar Olivares/Reuters)

Girls dressed in Soviet WWII uniforms of traffic control officers as Russian President Vladiimir Putin lays a wreath in the Hall of Military Glory of the Mamayev Kurgan memorial complex commemorating the Battle of Stalingrad to mark the 75th anniversary of the victory in the battle in Volgograd, Russia on February 2, 2018. The battle between Nazi troops and the Soviet Army was a major pivotal moment in the Great Patriotic War and World War II. (Photo by Mikhail Metzel/TASS via Getty Images)