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)

Liu Chunxia, a supporter of Xu Zhiyong, one of China's most prominent rights advocates, is detained by policemen while she gathers with other supporters nearby a court where Xu's trial is being held in Beijing January 22, 2014. When dozens of activists unfurled banners across the country last March and April calling for officials to disclose their assets, they did so at the urging of one of China's most prominent rights advocates, Xu Zhiyong. Xu, 40, stands trial on Wednesday on a charge of “gathering a crowd to disturb public order” punishable by up to five years in prison. His case will almost certainly spark fresh criticism from Western governments over Beijing's crackdown on dissent. (Photo by Kim Kyung-Hoon/Reuters)

A girl performs martial arts during a function to mark International Women's Day at a school in Hyderabad, India, on March 7, 2014. (Photo by Mahesh Kumar A./Associated Press)

People walk through crop circles in a cornfield near Raisting, Germany, on July 28, 2014. According to media reports, a balloonist had discovered the circle some days ago. Since then, hundreds of people came to the field to watch it, however it is unclear who did create the pattern. (Photo by Karl-Josef Hildenbrand/DPA)

“Sepak takraw or kick volleyball, is a sport native to the Malay-Thai Peninsula. Sepak takraw differs from the similar sport of volleyball in its use of a rattan ball and only allowing players to use their feet, knee, chest and head to touch the ball. It is a popular sport in Indonesia, Malaysia, Thailand, Singapore, Myanmar, Vietnam, Cambodia, Laos, and Philippines”. – Wikipedia

Photo: Hyun Ju Kim of Korea kicks over the net against Yukie Sato of Japan during the round robin match between Korea and Japan during day one of the ISTAF Sepaktakraw World Cup at Titiwangsa Stadium on July 21, 2011 in Kuala Lumpur, Malaysia. (Photo by Ryan Pierse/Getty Images for UFA Sports)

Lily Donaldson attends the “Loveless (Nelyubov)” screening during the 70th annual Cannes Film Festival at Palais des Festivals on May 18, 2017 in Cannes, France. (Photo by Tristan Fewings/Getty Images)

Courtney Stodden attends the finale of “Celebs Go Dating” TV show filming at Dirty Martini in London, England on July 26, 2017. (Photo by Beretta/Sims/Rex Features/Shutterstock)

People in costume take photos during a Halloween event on October 31, 2015 in Lan Kwai Fong, Central District, Hong Kong. Halloween, a named taken from 'All Hallows' Even' falls on the day before All Saints' Day on November 1, a holiday when Christians remember their deceased loved ones. (Photo by Jerome Favre/Getty Images)