San Diego Zoo's giant panda, Bai Yun, gives birth to a healthy cub
Late last month, the San Diego Zoo announced that its resident female giant panda, Bai Yun, was pregnant. Pandas' reproductive systems are still largely a mystery to researchers, so even zoo staff, who'd been monitoring Bai Yun extremely closely, didn't know when she would give birth.
Today just before 5 a.m., Bai Yun gave birth to what the zoo's senior research technician Suzanne Hall called a "vigorous, squawking" cub. For about 24 hours prior to the birth, Bai Yun had been restless, alternating between sleep and bouts of nest-building, Hall wrote on the zoo's blog. The cub's gender is not yet known.
Bai Yun is described by zoo staff as an excellent, attentive mother; she's given birth to four other cubs (Hua Mei, Mei Sheng, Su Lin and Zhen Zhen) since arriving at the zoo as part of a scientific exchange with China in 1996.
This pregnancy included an interesting development: An ultrasound last month revealed that Bai Yun was carrying not one, but two fetal cubs. But Hall pointed out at the time that, in one of the panda's previous pregnancies, she had also been found to be carrying two fetuses. Later ultrasounds conducted during the previous pregnancy, however, showed that Bai Yun's body had reabsorbed one of the fetuses, and only one was born.
With this pregnancy, zoo staff knew that one of the fetal cubs was well-developed and healthy, but it was clear from Bai Yun's first ultrasound that the other cub was smaller and less developed. Staff became increasingly doubtful that Bai Yun would carry the second cub to term. Writing shortly after the birth this morning, though, Hall acknowledged a very remote possibility that Bai Yun could still give birth to a second cub.
The odds are against panda twins; even when two cubs are born, it's rare for both to survive to adulthood. Panda cubs are born tiny (about 1/900th the size of their mothers), hairless and helpless, so raising even one is a labor-intensive task for a mother panda. However, Bai Yun's adult daughter, Hua Mei, has raised three sets of twins, albeit with a great deal of assistance from staff at the Wolong Giant Panda Research Center in China, where she was sent to live in 2004.
In keeping with Chinese tradition, the cub will not be given a name until it's 100 days old, our sister blog L.A. Now reports.
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-- Lindsay Barnett
Photo: Bai Yun with one of her older cubs, Mei Sheng, in 2004. Credit: Ken Bohn / AFP/Getty Images