In this October 15, 2014 file photo, Katsu Nakamura, sky division manager for Yamaha USA, moves the RMax unmanned helicopter into position before a demonstration of its aerial application capabilities at the University of California, Davis' Oakville Station test vineyard in Oakville, Calif. Researchers at UC Davis have been studying the effectiveness of the drone's ability for spraying pest control and nutritional materials on the test vineyard in California's Napa Valley. (Photo by Rich Pedroncelli/AP Photo)

Bolivia's president Evo Morales holds his scared staffs of power during a blessing by Aymaran spiritual guides, in a traditional ceremony at the archeological site Tiwanaku, Bolivia, Wednesday, January 21, 2015. Morales is set to begin a new term Thursday, that will make him the Andean nation's longest-serving leader, riding high on a wave of unprecedented growth and stability. (Photo by Juan Karita/AP Photo)

Children play on an abandoned car near a protest, which is against the dissolution of Yemen's parliament and the Shi'ite Muslim Houthi militia's tightening grip on power, in the southwestern city of Taiz, February 13, 2015. (Photo by Mohamed al-Sayaghi/Reuters)

Visitors photograph an animatronic Tyrannosaurus Rex at the National Museum of Scotland, July 29, 2011. (Photo by David Moir/Reuters)

A mahout watches the Thai animation movie Kan Kluay with his elephant in Ayuthaya province, about 80km (49 miles) north of Bangkok June 5, 2006. The movie tells the story of a young Thai wild elephant who, while looking for his father, becomes the war elephant of the Thai King fighting against Burma and restored Thailand's ancient Ayuthaya empire that existed about 400 years ago. (Photo by Sukree Sukplang/Reuters)

A boy dressed like Hindu Lord Krishna waits to attend celebrations on the eve of Janmashtami at a school in Mumbai, India, Friday, September 4, 2015. The day marks the birth of Krishna. (Photo by Rajanish Kakade/AP Photo)

The first red panda cub was born on May 30 in zoo Zlin. Zoologist Roman Vrzal holds a male of red panda. The Red panda is pictured in Zlin, Czech Republic, August 20, 2014. (Photo by Dalibor Gluck/CTK)

U.S. Air Force pilots with the Thunderbirds perform the calypso pass maneuver in F-16 Fighting Falcon aircraft during a practice session prior to the Gunfighter Skies air show at Mountain Home Air Force Base, Idaho, September 19 and released September 24, 2014. (Photo by Tech. Sgt. Manuel J. Martinez/Reuters/US Air Force)