A 21-year-old giant panda in southwest China was blessed to have one more baby Saturday morning a day after researchers announced that a son of hers will leave her for Spain for a cooperative research program.

The mother panda Bing Bing gave birth to a 125.5-gram female cub at 8:46 a.m. Saturday after 146 days of pregnancy and 13 hours of labor in Chengdu, capital of southwest China's Sichuan Province.

It is very rare for giant pandas of more than 20 years old to give birth, as they begin to breed at four and normally stop before 20, said Zhang Zhihe, head of the Giant Panda Breeding and Research Base in Chengdu.

The mother and the daughter are in good health, Zhang said.

The cub is Bing Bing's fifth baby, after Lun Lun, the female panda on loan to the United States, and Bing Xing, the male panda to be sent to Spain for research.

Chinese researchers announced Friday that 7-year-old Bing Xing and the other panda "Hua Zui Ba" will be sent to Spain for an international cooperation program on endangered pandas.

Giant pandas, also known as "living fossils", are among the world's most endangered species. Figures show only 1,590 pandas now live in the wild, mostly in the mountains of Sichuan, and 217 in captivity by the end of 2006.