Panda at San Diego Zoo Is Pregnant With Twins

Nobody knows exactly how long giant panda Bai Yun has been pregnant, and there is some question about who the father is.

Still, officials at the San Diego Zoo were beaming like expectant parents Monday, eagerly awaiting the birth of black-and-white twins due this month.

If all goes well, the birth would mark a rare success in panda reproduction, and also could help the zoo boost attendance.

Pandas have long captivated zoo visitors, who wait in long lines to see the cuddly looking bears and snap photos of their every move.

Some of the nation’s most popular pandas have become mini-celebrities, garnering extensive media attention and spawning souvenirs featuring their fuzzy faces.

“Panda twins are something that people are going to want to see,” said Yadira Galindo, a spokeswoman for the Zoological Society of San Diego, which runs the zoo and the San Diego Wild Animal Park.

Zoo employees discovered the pregnancy Sunday while conducting a routine ultrasound on Bai Yun, a 13-year-old female giant panda on loan from China.

The ultrasound produced the images of two fetuses, and veterinarians were able to detect two distinct heartbeats.

The babies would be the first giant pandas born in North America since Bai Yun gave birth to the popular Hua Mei four years ago.

“We’re so proud,” said Don Lindburg, who heads the zoo’s giant panda conservation office. “We’re keeping our fingers crossed that everything goes well.”

Pregnancy in pandas lasts about 135 days, and the babies are expected to weigh 4 ounces at birth.

Pandas have twins in about 50% of births, but they reject one of the babies immediately. Little is known about how and why they select only one.

If both twins survive birth, the zoo will wait until Bai Yun chooses one twin to nurse and then zoo staff will bottle-feed the other. They also may try to switch the babies so that the mother nurses both.

The father is believed to be Gao Gao, who arrived in San Diego at the beginning of the year and mated with Bai Yun during breeding season in late March, Lindburg said.

“He surprised us,” Lindburg said. Bai Yun also was artificially inseminated with sperm from the elderly Shi Shi, who is now in China. Bai Yun and Shi Shi were brought to San Diego in 1996 under an agreement between the U.S. and China.

As part of that agreement, the Zoological Society contributes $1 million annually to promote habitat protection of wild pandas in China.

The news about San Diego’s pregnant panda traveled quickly. “This is absolutely marvelous,” said David Towne, head of the Giant Panda Foundation and former director of the Woodland Park Zoo in Seattle.

“Even just having a couple of healthy embryos in there is exciting. Let’s hope it all turns out successfully.”

Towne attributed the pregnancy to San Diego’s close collaboration with China and the recent arrival of the young male.

“You’ve got to have the right parents and the right circumstances,” he said.

Scientists throughout North America will be watching the pregnancy and birth carefully because zoos have had trouble mating pandas, both naturally and through artificial insemination.

In the 1980s at the National Zoo in Washington, pandas failed to produce a surviving cub despite four births in four seasons. There also have been cases of pandas smothering their newborns.

China has had somewhat more success in breeding captive pandas. One panda there, Qing Qing, known as “heroic mama,” has given birth to four sets of twins and four other offspring since 1989.