A man holds a pigeon during the British Homing World show of the year at Blackpool's Winter Gardens in Blackpool, north west England on January 17, 2016. Homing pigeon fanciers from across Europe gathered to find the Supreme Show Champion with judges casting their eyes over hundreds of birds on show. The Royal Pigeon Racing Association organises the event and has Queen Elizabeth II, who keeps pigeons at Sandringham, as its patron. (Photo by Andrew Yates/Reuters)

A combination photo shows the faces of various attendees of New York Comic Con in Manhattan, New York, October 8, 2015. The event draws thousands of costumed fans, panels of pop culture luminaries and features a sprawling floor of vendors in a space equivalent to more than three football fields at the Jacob Javits Convention Center on Manhattan's West side. (Photo by Andrew Kelly/Reuters)

Wang Zhengqing, a 74 year old pneumoconiosis patient, smokes his pipe at Yangjia Hospital in Wuyi County, Zhejiang Province, China October 19, 2015. Former miner Wang was diagnosed with the disease, which is caused by dust inhalation, when he was 24 and has lived at Yangjia Hospital for ten years. (Photo by Damir Sagolj/Reuters)

In this Tuesday July 12, 2016 photo, an elephant is lifted by a crane in an upside down position in Lilongwe, Malawi, in the first step of an assisted migration of 500 of the threatened species. African Parks, which manages three Malawian reserves is moving the 500 elephants from Liwonde National Park, this month and next, and again next year when vehicles can maneuver on the rugged terrain during Southern Africa's dry winter. (Photo by Tsvangirayi Mukwazhi/AP Photo)

Boys walk home for lunch from school in the village of Kogelo, west of Kenya's capital Nairobi, July 16, 2015. U.S. President Barack Obama visits Kenya and Ethiopia later this month. His ancestral home of Kogelo is home to Sarah Hussein Obama, his step-grandmother. The Kenyan village, burial place of Obama's father, features an open-pit goldmine, a pork butcher's, a school named after their most famous son and outdoor market stalls. Villagers get around by motorbike taxi or on foot while a donkey-cart transports water. Children, some of them named Obama in honour of the President, walk to and from school together. (Photo by Thomas Mukoya/Reuters)

Attendees dressed as Poison Ivy and Harley Quinn arrive for opening day of the annual Comic-Con International in San Diego, California, United States July 21, 2016. (Photo by Mike Blake/Reuters)

A costumed fan attends Comic-Con International 2014 – Day 1 on July 24, 2014 in San Diego, Calif. (Photo by Joe Scarnici/FilmMagic/Getty Images)

Attendees at Wizard World Comic Con walk through hallways in Chicago, Illinois, United States, August 22, 2015. (Photo by Jim Young/Reuters)