Bai Yun e Yun Zi allo Zoo di San Diego, California, USA

(AP Photo/Ken Bohn, San Diego Zoo)

21/12/2009 - Giant Panda mom Bai Yun playing with her four-and-half-month old baby boy, Yun Zi, at their enclosure at the San Diego Zoo. Yun Zi has been reluctant to leave the comfort of his den, but Monday’s successful venture outdoors means it is likely that within a month the cub will go on exhibit to the public. Yun Zi is the fifth giant panda born at the San Diego Zoo. The first surviving giant panda born in the United States was born in San Diego in 1999. Other cubs were born at the Zoo in 2003, 2005, 2007, and most recently this cub, born on Aug. 5, 2009.