Imperial Valley News

San Diego, California - Giant panda Bai Yun hasn’t gained extra weight and there is no swelling of her abdomen, but using a thermal camera and an ultrasound machine, San Diego Zoo experts are seeing images that confirm the mother of four is expecting another cub.

Ultrasound video taken Monday clearly showed a panda fetus. The tiny panda moves its paws and tucks its head in. If it is carried to term the panda will be born weighing a mere 4 ounces and about the size of a stick of butter.

“We continue to learn more about giant panda reproduction every year,” said Meg Sutherland-Smith, San Diego Zoo veterinarian. “Unfortunately there are still no hormone tests to confirm a pregnancy early on. We rely on ultrasound images to see the development of a fetus, and based on previous years’ observations we can predict a birth will occur in August.”

The heartbeat of a second fetus has also been detected during this pregnancy, but its viability is still in question since it does not appear to be developing as quickly as the first fetus.

In 2003 and 2005, the giant panda team was able to document that Bai Yun was carrying two fetuses during both pregnancies. However, as the birth approached one fetus was resorbed, leaving only one cub to be born.

Bai Yun has delivered four healthy cubs at the San Diego Zoo. In 1999, her first cub, Hua Mei, became the first giant panda conceived by artificial insemination in the western hemisphere and the first in the United States to survive to adulthood. Hua Mei is now in a breeding program in the People’s Republic of China along with her brother, Mei Sheng, who was born in San Diego in 2003 through natural breeding.

Two of Bai Yun’s other offspring, Su Lin and Zhen Zhen, born in 2005 and 2007 respectively, remain at the San Diego Zoo.

Bai Yun and Gao Gao mated naturally in April. The panda’s fertilized egg remains suspended until a trigger in the environment indicates it is time to implant. The trigger is still unknown to scientists. Giant pandas routinely delay the implantation of the fetus as much as two to three months. The team estimates implantation occurred in Bai Yun six to seven weeks ago. After implantation the fertilized egg begins to develop. Impending birth is predicted on the basis of behavioral, hormonal and anatomical changes documented by scientists at the San Diego Zoo’s Institute for Conservation Research.

Bai Yun is in an off-exhibit habitat where she has been showing signs of a pregnancy, including changes in her hormone levels, nest building and a loss of appetite. If a cub is born, Bai Yun and the cub will remain in the den for four to five months. The male, Gao Gao, has no role in raising the cub. During the denning period, the only way to see the panda cub and mother will be through the San Diego Zoo’s live Panda cam, available at www.sandiegozoo.org/pandacam .

Bai Yun was born at the China Center for Research and Conservation of the Giant Panda in the Wolong Nature Reserve on Sept. 7, 1991. She was the first panda to be born and survive at the breeding center. Bai Yun, who’s name means “white cloud” in Chinese, arrived at the San Diego Zoo in September 1996 on a research loan.

The 100-acre San Diego Zoo is dedicated to the conservation of endangered species and their habitats. The organization focuses on conservation and research work around the globe, educates millions of individuals a year about wildlife and maintains accredited horticultural, animal, library and photo collections. The Zoo also manages the 1,800-acre San Diego Zoo’s Wild Animal Park, which includes a 900-acre native species reserve, and the San Diego Zoo’s Institute for Conservation Research. The important conservation and science work of these entities is supported in part by The Foundation of the Zoological Society of San Diego.