Tom Wilder, 17 from Kent, dives in the mud at the Glastonbury Festival site at Worthy Farm, Pilton on June 23, 2011 in Glastonbury, England. Music fans had to brave more rain today at the five-day festival which opened yesterday. This year the festival will feature headline acts U2, Coldplay and Beyonce. The festival, which started in 1970 when several hundred hippies paid 1 GBP to watch Marc Bolan, has grown into Europe's largest music festival attracting more than 175,000 people over five days. (Photo by Matt Cardy/Getty Images)

Tom Nevins guts a feral pig sow during hunting on Silver Plains Station on October 8, 2011 outside of Coen, Australia. Feral pigs are recognised as environmental and agricultural pests reported to have a population of up to 23.5 million over around half of Australia. The Cooktown Hog Hunt is held annually with this year's hunting window open from registration at 2pm on Friday to the end of weigh in at 2pm on Sunday afternoon. (Photo by Mark Kolbe/Getty Images)

Chinese Kazakh eagle hunters sit on horseback as they travel to a local competition on January 29, 2015 in the mountains of Qinghe County, Xinjiang, northwestern China. The festival, organised by the local hunting community, is part of an effort to promote and grow traditional hunting practices for new generations in the mountainous region of western China that borders Kazakhstan, Russia and Mongolia. The training and handling of the large birds of prey follows a strict set of ancient rules that Kazakh eagle hunters are preserving for future generations. (Photo by Kevin Frayer/Getty Images)

An arial view of Top Pearsy's Maize Maze in the shape of Harry Potter, on July 11, 2011 in York, England. Farmer Tom Pearcy has cut two portraits of Harry Potter in his crop of maize plants. With some subtle differences the two images create the world's largest spot the difference competition. At over 50m in diameter, and cut out of over 1 million living maize plants, the York Maze is the largest “Maize Maze” in Europe and one of the largest in the world. (Photo by Bethany Clarke/Getty Images)

Three elephant seals put on a show in Roie Galitz's “Three Tanors”, taken on January 7, 2016 in South Georgia Island. The Comedy Wildlife Photography Awards are in full swing, so check out some of the fierce competitors jostling for the top prize this year. Photographers Paul Joynson-Hicks MBE and Tom Sullam founded the awards to spotlight wildlife conservation efforts and to inject some humour into the world of wildlife photography. (Photo by Roie Galitz/CWPA/Barcroft Images)

A general view of atmosphere during the NYC “Soul Train” Line Flash Mob: Hippest Trip in America in honor of Don Cornelius in Times Square on February 4, 2012 in New York City. Cornelius, the creator of “Soul Train”, died on February 1, 2012 at the age of 75. (Photo by Ilya S. Savenok/Getty Images)

Female sea lion “Sarasa” holds a hose with her mouse to help a trainer clean her room at the Shinagawa Aqua Stadium aquarium in Tokyo on December 30, 2014. The aquarium is carrying out year-end general cleaning of their facilities. (Photo by Yoshikazu Tsuno/AFP Photo)

A General Atomics MQ-9 Reaper stands on the runway during “Black Dart”, a live-fly, live fire demonstration of 55 unmanned aerial vehicles, or drones, at Naval Base Ventura County Sea Range, Point Mugu, near Oxnard, California July 31, 2015. (Photo by Patrick T. Fallon/Reuters)