The female panda in the Taipei Zoo, sent to Taiwan as a gift from the Chinese mainland, has shown signs of pregnancy after being artificially inseminated, according to the zoo's director.

Yuan Yuan plays in the Taipei Zoo. [chinanews.com]

The panda, named Yuan Yuan, had been sleepy in recent days and refused to be touched by keepers, which are clear signs of pregnancy although no fetal movement had been detected by ultrasound so far, said the zoo's director Jason Yeh on Sunday.

She slept currently more than 15 hours a day, Yeh told Xinhua.

Yuan Yuan and a male panda Tuan Tuan (the names together mean "reunion" in Chinese) were given to Taiwan in 2008 amid improved cross-Strait ties. Yuan Yuan was born on Aug. 30, 2004, just two days before Tuan Tuan.

A delegation from Sichuan Province, headed by provincial governor Jiang Jufeng, visited the the panda couple on Sunday. The pandas lived in Sichuan, the main habitat of the endangered animal, before they settled in Taiwan.

Jiang said he was glad to see they live well in Taiwan, and he wished the couple have many children.

The Sichuan delegation also sent experts to help the Taipei zoo take care of the mother-to-be.

The Taipei Zoo announced in February that staff had artificially inseminated Yuan Yuan after Tuan Tuan showed no interest in mating. The mainland authorities said days later that Taiwan may keep the couple's cubs.

The pandas go to heat only once a year, usually during early spring. This year, the reproductive period of Yuan Yuan started on Jan. 29 after she lost her appetite and kept walking around or cooled herself down by soaking in the pool.

Tuan Tuan, however, was not as passionate as Yuan Yuan and was interested only in feeding and sleeping.

Female pandas in captivity become sexually mature earlier than their male counterparts, and their pregnancies continue for 83 to 200 days.

Reproduction of captive giant pandas has long been a problem, so artificial insemination is common.

Giant pandas are among the world's most endangered animals. An estimated 1,590 pandas live in the wild on the mainland, mostly in the mountains of Sichuan and the northwestern Shaanxi and Gansu provinces. About 200 giant pandas have been bred in captivity.