CHENGDU: US-born giant panda Hua Mei gave birth to twin panda cubs on Wednesday, officials at the China Wolong Giant Panda Protection and Research Centre announced yesterday.

The panda cubs weighed in at a hearty 157 grams and 130 grams each.

Both mother and baby pandas are healthy and sound, said Huang Yan, a deputy chief engineer at the centre.

Hua Mei showed signs of preparing for delivery about noon on Wednesday

It took about six hours before she smoothly delivered the first cub. In less than an hour, she gave birth to another panda infant. Though tired, the mother panda is apparently doing well, officials said.

Considering that Hua Mei lacks experience in nurturing cubs as a first-time mother, caretakers at the Wolong centre took away one of the cubs a male for an artificial upbringing.

Hua Mei, meaning "China-America," is the cub of Bai Yun and Shi Shi, a panda couple leased by China to the renowned San Diego Zoo in California. They went there in 1996 as part of a 12-year research co-operation programme between the two nations.

The 5-year-old Hua Mei is China's first overseas-born panda. Upon returning to the mainland last February, Hua Mei underwent a month of observation. When she became accustomed to her new environment, she mated with panda Ling Ling, and was found to be pregnant on May 2.

A female panda normally becomes sexually mature at 4 to 5 years old.

The panda breeding cycle usually occurs just once a year, with the bears mating between March and May during a three-to-four-day window.

The pandas have a relatively low fertility rate, and are one of the most endangered species in the world.

Typically, mothers give birth to one or two cubs at a time. Panda gestation lasts 83 to 181 days.

The State Forestry Administration said the number of pandas in China has risen by more than 40 per cent from 1,110 in the 1980s to 1,590 today, while a total of 161 are in captive breeding programmes worldwide.

However, while the panda population has increased, the animal's existence is also menaced by loss of habitat. Also, groups of pandas live far from one another, making breeding difficult.

The Wolong centre, founded in 1963, is the largest panda reserve in China. It has an area of 200,000 hectares and is renowned as a panda refuge.

(China Daily 09/03/2004 page1)