Through it all, Bai Yun dozed in a tree, and in a separate enclosure next door, her male neighbor Shi Shi napped on the ground.
Researchers say the project is the last hope for the endangered animals.
Fewer than 1,000 exist in the wild, all in China. A single male at Washington's National Zoo is the only other panda in the United States. Shi Shi, however, was content to sleep through the afternoon, oblivious to such concerns. Any reaction other than this would have been out of character. Not all of the visitors were disappointed.