Poland's Dawid Kubacki soars through the air during the men's FIS Ski Jumping World Cup competition in Engelberg, central Switzerland, on December 20, 2014. (Photo by Fabrice Coffrini/AFP Photo)

A rebel fighter carries his weapon as he moves through a hole in a wall in the old city of Aleppo near the frontline against forces loyal to Syria's President Bashar al-Assad December 28, 2014. (Photo by Jalal Al-Mamo/Reuters)

Miss Australia 2014 Tegan Martin sits down with Miss Universe Chief Photo Editor Francis L. Szelwach to review her photos after posing in swimwear at the 63rd annual Miss Universe pageant in Miami, Florida, in this January 5, 2015 handout photo provided by the Miss Universe Organization. (Photo by Reuters/Miss Universe Organization)

In this undated photo made available by journal Nature on January 15, 2014, a northern bald ibis (Geronticus eremita) flies in Tuscany, Italy. A new study released Wednesday, January 15, 2014 says the birds choreograph the flapping of their wings, getting a boost from an updraft of air in the wake of the flapping wings by flying behind the first bird and off to the side. When a flock of birds take advantage of these aerodynamics, they form a V. (Photo by Markus Unsöld/AP Photo)

A newborn baby giraffe shows its tongue at the Planckendael zoo in Mechelen, 25 kilometers North of Brussels, Tuesday, February 18, 2014. The calf was born on Valentines day, February 14, and has a heart shaped spot on the hip. (Photo by Yves Logghe/AP Photo)

Monks dressed as Tibetan Buddhism characters attend a religious ceremony, known as “Da Gui” or beating ghost, to celebrate the upcoming Tibetan New Year which starts on March 1 at Yonghegong Lama Temple, in Beijing February 28, 2014. This Tibetan ceremony is held annually at the end of the first lunar month with mask dancing to expel ghosts, according to a press release. (Photo by Jason Lee/Reuters)

In this Thursday, April 11, 2013 photo, North Korean female soldiers stand watch on the river bank of the North Korean town of Sinuiju, opposite to the Chinese border city of Dandong. (Photo by AP Photo)

A protester uses molotov cocktails against riot police during May Day protests on May 1, 2010 in Athens, Greece. (Photo by Milos Bicanski /Getty Images)