People take part in the Classic Ride Rally in downtown Valencia, eastern Spain, 23 November 2014. Some hundred people on classic bikes from the 20's to the 70's participated in the rally. (Photo by Kai Foersterling/EPA)

A couple of monkeys look from inside their cage at a rescue and rehabilitation center in Santiago, Chile, Saturday, November 22, 2014. Elba Munoz who runs the center, says that one of the goals of the Center for the Rescue and Rehabilitation of Primates is to stop the trafficking of the animals. (Photo by Luis Hidalgo/AP Photo)

Spectators cheer as the United Launch Alliance Delta 4-Heavy rocket, with NASA's Orion spacecraft mounted atop, lifts off from the Air Force Station, December 5, 2014, in Cape Canaveral, Fla. (Photo by Smiley N. Pool/AP Photo/Houston Chronicle)

A panda bear sits on a logs in a zoo on January 15, 2015 in Hangzhou, China. (Photo by Feature China/Barcroft Media)

A street artist dances tango in Buenos Aires, Argentina, Tuesday, January 20, 2015. Tango is a partner dance that originated in the 1890's along the Rio de la Plata, the border between Uruguay and Argentina. UNESCO approved in 2009, a joint proposal by the two nations to include the dance in its Intangible Cultural Heritage List. (Photo by Rodrigo Abd/AP Photo)

Members of the “Avalon” team wearing 14th century knight costumes fight against each other on the bank of the Yenisei River during the regional amateurs tournament of clubs of historical reconstruction, “The Battle of the Nations 2015. Siberia”, in Krasnoyarsk January 24, 2015. (Photo by Ilya Naymushin/Reuters)

Residents carry a slaughtered pig with a bamboo pole as they walk home on a street, which was shut to traffic due to ice, in Leishan county, Guizhou province January 31, 2015. Blizzards and icy rain that lasted for several days at the end of January have disrupted traffic, collapsed houses and decimated crops in central Chinese provinces, Xinhua News Agency reported. (Photo by Reuters/Stringer)

A female Indian rhinoceros called Maruska eats a vegetable birthday cake on her first birthday celebration at the Plzen Zoo on February 3, 2015 in Plzen, Czech Republic. (Photo by Ladislav Nemec/Isifa)