White lioness Azira lies in the cage with her three white cubs, on February 4, 2014. Zoo owner Andrzej Pabich says white lions often have defects that prevent giving birth, or the mother rejects her cubs, but Azira has been patiently feeding and caring for her little ones. (Photo by Czarek Sokolowski/Associated Press)

A young oriental small-clawed otter at the zoo in Neumuenster, Germany, March 5, 2014. The six young otters (one male, five female) were born on December 7, 2013. (Photo by Maja Hitij/EPA)

Chinese security stands near a Long March 2F rocket carrying Tiangong-1, China's first unmanned space module, stands at the Jiuquan Satellite Launch Center on September 28, 2011 in Jiuquan, Gansu Province of China. Tiangong-1,a small unmanned space lab, will be launched at 21:19 (Beijing time) on September 29, 2011, and will attempt a docking procedure with a Shenzhou 8 spacecraft later in the mission. (Photo by Lintao Zhang/Getty Images)

Entertainment One is attempting to set the Guinness World Record for the longest chain of brides in one location at HMV, Oxford Street on March 11, 2012 in London, United Kingdom. The event was held to celebrate to celebrate the DVD release of The Twilight Saga: Twilight Breaking Dawn Part 1 (Photo by Dave J. Hogan/Getty Images)

A prototype battery-powered plane, called Greased Lightning or GL-10 is pictured flying at NASA's Langley Research Center in this undated handout photo obtained by Reuters May 1, 2015. The plane, which has 10 engines and can take off like a helicopter and fly efficiently like an aircraft, is currently in the design and testing phase. (Photo by Reuters/NASA)

A girl presents the new Oktoberfest beer festival mug in a Oktoberfest tent in Munich, southern Germany, on August 21, 2014. The world famous beer festival Oktoberfest will takes place from September 20 to October 5, 2014. (Photo by Christof Stache/AFP Photo)

Members of the Russian Red Army Choir perform at Water Front Theatre in Beirut September 13, 2014. (Photo by Jamal Saidi/Reuters)

A P-51 Mustang named “Charlotte's Chariot” from the Southern Heritage Air Foundation flies past a cloud of smoke and fire from a nearby battle reenactment during the Wings Over Houston Airshow in Houston, on Saturday, November 1, 2014. Battle reenactments are part of the yearly show held at Ellington Airport. (Photo by Kar Hlava/AP Photo/Bay Area Citizen)