Merit Prize Winner: “A Well Earned Rest in the Sahara”. This photo of Moussa Macher, our Tuareg guide, was taken at the summit of Tin-Merzouga, the largest dune (or erg) in the Tadrat region of the Sahara desert in southern Algeria. Moussa rested while waiting for us to finish our 45-minute struggle to the top. It only took ten minutes of rolling, running, and jumping to get back down. The Tadrat is part of the Tassili N'Ajjer National Park World Heritage area, famous for its red sand and engravings and rock paintings of cattle, elephants, giraffes, and rhinos that lived there when the climate was milder. Photo location: Summit of Tin-Merzouga, Tadrat, Tassili N'Ajjer National Park, Algeria. (Photo and caption by Evan Cole/National Geographic Photo Contest)

Recording artist Ariana Grande performs onstage during the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on September 19, 2014 in Las Vegas, Nevada. (Photo by Kevin Winter/Getty Images for iHeartMedia)

Trevor Olson, from Minnesota, dressed as the character “Joker”, poses for a photograph at New York's Comic Con convention, October 9, 2014, in New York City. The event draws thousands of costumed fans, panels of pop culture luminaries and features a sprawling floor of vendors in a space equivalent to more than three football fields in Javits Center. (Photo by Shannon Stapleton/Reuters)

“A Mothers Tail”. A baby cub pulls on his mother's tail to get attention. Photo location: Masai Mara, Kenya. (Photo and caption by Tori Marsh/National Geographic Photo Contest)

Miss Nord-Pas-de-Calais Camille Cerf (C) is congratulated by Miss Ile de France 2014 Margaux Savary (L) and Miss Auvergne 2014 Morgane Laporte after Cerf won the Miss France 2015 beauty contest on December 6, 2014 in Orleans. (Photo by Guillaume Souvant/AFP Photo)

In this April 28, 2014 file photo, a woman throws a rock and a bag at police blocking her from getting home in the Huepetuhe district of the Madre de Dios region of Peru. Security forces began destroying illegal gold mining machinery in Peru's southeastern jungle region of Madre de Dios, as authorities began enforcing a ban on illegal mining. (Photo by Rodrigo Abd/AP Photo)

Grey seal pup “Nikolaus” licks a window at the seal enclosure in Friedrichskoog, Germany, 19 December 2014. The pup was abandoned by his mother and would not have a chance at survival without human help. Nikolaus will be fed at the enclosure for two to three months until he has reached the minimum weight of 45 kilograms for being released. (Photo by Daniel Reinhardt/EPA)

A winter swimmer, wearing a Santa Claus hat to celebrate the upcoming Christmas, reacts as he plays on a frozen lake at a park in Shenyang, Liaoning province, December 22, 2014. The characters on the hat read: “Shenyang Winter Swimming”. (Photo by Reuters/Stringer)