An 18-year-old female giant panda gave birth to three cubs in southwest China but only one cub survived, with experts saying the rare phenomenon could help them learn more about the endangered species.

The panda, named Jiaozi, delivered the triplets in Sichuan Province last month, said a researcher at the Chengdu Research Base of Giant Panda Breeding.

The survivor is female and weighs 96 grams. It is being bred by staff because as she is unwell and her mother cannot produce milk.

"Giant pandas often give birth to a singleton or twins. The phenomenon of triplets is rare, especially at such an old age like Jiaozi," said Hou Rong, the center's deputy director.Jiaozi at the age of 18 is equivalent to a 50-year-old woman.

Hou said Jiaozi had a fever and poor appetite after she delivered the three cubs, and there was a fear she may not survive. However, she is now out of danger, state-run Xinhua news agency reported.

Jiaozi's experience, from pregnancy to delivery, provides the center with valuable information about the birth of triplet cubs, Hou said.

The panda, born in 1995, has given birth to 10 cubs and seven are alive.

A giant panda named Yongba, gave birth to triplets at the age of 16 in 1999 but only one survived.

In 1967, another female panda in a Shanghai zoo gave birth to three cubs but none survived.

Giant pandas are one of the world's most endangered species. About 1,600 live in the wild, mostly in the mountains of Sichuan, while more than 300 live in captivity.