By JESSICA GRESKOAssociated Press
WASHINGTON (AP) - The birth of a panda cub this weekend at Washington's zoo was cause for a party, but behind the excitement there's also now some nail-biting.
Panda cubs are born hairless and helpless, about the size of a stick of butter. The tiny cubs are at risk for infections and so small that it's not unheard of for panda moms to accidentally crush their young. For the National Zoo, which has only had one panda cub survive, the memories of past tragedies are real.
Zoo officials are watching panda mom Mei Xiang and her cub via video camera around the clock. It will be a few weeks before they can get in and examine the cub.
Every week that passes, zoo officials will breathe a little easier.
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