Giant Panda Carries Twins

Like proud parents, San Diego Zoo officials announced Thursday that one of their giant pandas was expecting twins.

Bai Yun, whose name means White Cloud, has shown signs of pregnancy since mid-July, making a nest in the zoo’s birthing den, eating less and spending more time indoors, officials said.

Zoo veterinarians observed two heartbeats during an ultrasound last week and Tuesday actually saw both fetuses during a second ultrasound.

Zookeepers had been hopeful for another pregnancy from the two-time mother. The father is Gao Gao, whom officials spotted mating with Bai Yun earlier this year.

“We are tremendously excited,” said Don Lindburg, the giant panda team leader at the zoo, in a statement.

Zoo officials cautioned that it is very common for pandas to become pregnant with twins and give birth to only one cub. Last time Bai Yun gave birth, she had carried twins but bore only one. This time, one of the fetuses looks smaller and weaker than the other, officials said.

Panda pregnancies generally last about 135 days, and when the babies arrive, they weigh about 4 ounces. Zoo officials will put Bai Yun on 24-hour birth watch starting today.

Bai Yun, who is 13, is on loan with Gao Gao from the Chinese government.

Six years ago, she gave birth to the first giant panda to survive to adulthood in North America, Hua Mei. She gave birth to Mei Sheng in 2003.