Lioness and hyena posture to one another, in Masai Mara, Kenya, August 2015. A photographer captured one of the oldest rivalries in the animal kingdom as a pair of lions went head to head with a pack of hungry hyenas. (Photo by Ingo Gerlach/Barcroft Images)

Policemen take pictures of the Soyuz TMA-17M spacecraft while it is transported from an assembling hangar to its launch pad at the Baikonur cosmodrome, Kazakhstan, July 20, 2015. The Soyuz is scheduled to blast off with Kjell Lindgren of the U.S., Kimiya Yui of Japan and Oleg Kononenko of Russia to the International Space Station on July 23, 2015. (Photo by Shamil Zhumatov/Reuters)

Participants prepare backstage during Belarus bodybuilding and fitness championship in Minsk April 25, 2015. (Photo by Vasily Fedosenko/Reuters)

A six-year-old acrobat performs on the opening of a tourist festival in Bozhou, Anhui province, China May 3, 2015. (Photo by Reuters/China Daily)

A mahout splashes water on his elephant in the river Sabarmati on a hot summer day in Ahmedabad, India, May 20, 2015. (Photo by Amit Dave/Reuters)

A Dandy Dinnmont Terrier is displayed at the World Dog Show in Rho, near Milan, Italy, Saturday, June 13, 2015. (AP Photo/Luca Bruno)

A gibbon drinks from a soft drink bottle, given by a tourist, at a zoo in Kunming, Yunnan province, June 18, 2015. (Photo by Wong Campion/Reuters)

A reveller smiles as she walks in the rain at Worthy Farm in Somerset during the Glastonbury Festival in Britain, June 28, 2015. (Photo by Dylan Martinez/Reuters)