Marcelo Gutierrez of Colombia in action during the Valparaiso mountain bike downhill race in Valparaiso, Chile on February 11, 2018. Runners from around the world participated in the mountain bike race on the streets of the port. (Photo by Rodrigo Garrido/Reuters)

A flock of starlings is seen as they perform their traditional dance fly before landing to sleep during the sunset near the southern Arab Israeli city of Rahat, in the northern Israeli Negev desert, on February 2, 2015. (Photo by Menahem Kahana/AFP Photo)

French photographer Laurent Chehere's “Flying Houses” exhibit takes workaday houses and lets them lift the imagination. The exhibit is showing at the Muriel Guépin Gallery in New York. Photo: Laurent Chehere's “Flying Houses”: “The Great Illusion”. (Photo by Laurent Chehere)

Dan McManus and his service dog Shadow hang glide together outside Salt Lake City, Utah, July 22, 2013. McManus suffers from anxiety and Shadow's presence and companionship help him to manage the symptoms. The two have been flying together for about nine years with a specially made harness for Shadow. (Photo by Jim Urquhart/Reuters)

A boy flies his kite in a cemetery in the Vila Operaria Favela of Rio de Janeiro, Brazil, July 9, 2016. (Photo by Nacho Doce/Reuters)

These pictures show a rather annoying crow irritating an eagle. The crow tirelessly circles the bird of prey and repeatedly lands on his head – much to the crows displeasure. The encounter was spotted by Greaves Henriksen in Tamilnadu, India. The 52-year-old amateur photographer believes the eagle was sitting close to a nest, which the crow was trying to defend. Here: A crow lands on the eagles head much to the eagles displeasure. (Photo by Greaves B. Henriksen/Caters News Agency)

These greenfinches go head to head in what appears to be a heroic fight or a playfull moment together, inspiration for a new version of “Angry Birds”, in Trezzo Sull'Adda, Italy in March 2013. (Photo by Marco Redaelli/IMP/AbacaPress.com)

A window cleaner passes a lighter to his colleague while rappelling from a new building in Tianjin March 23, 2007. (Photo by Reuters/Stringer)