Washington, D.C. is saying goodbye to Tai Shan, the adorable panda whose birth four and a half years ago in the nation’s capital caused widespread “panda-monium.” Nicknamed “Butterstick” for his tiny size and near-hairlessness at birth, Tai Shan travels to China Saturday, where he'll be put out to stud. Tai Shan was a media darling, gracing many front pages and drawing two million visitors to the Smithsonian National Zoo. A video of him sneezing as a young cub garnered 51 million hits on YouTube, and a pandacam follows him 24/7. "We're all very sad to see him go," a senior curator at the zoo said. "But we're so excited he's going to China to be part of the breeding program and to fill the world with more pandas." There are only 1,600 pandas left in the wild.