In this photo taken Tuesday, Nov. 17, 2009, an 18-month old panda bear is trained to walk on its hind legs to build strength ahead of the crucial mating season at a wild animal rescue and research center in Zhouzhi county in northwestern China’s Shaanxi province. (AP Photo)

In this photo taken Tuesday, Nov. 17, 2009, an 18-month old panda bear is trained to walk on its hind legs to build strength ahead of the crucial mating season at a wild animal rescue and research center in Zhouzhi county in northwestern China’s Shaanxi province. (AP Photo)