The San Diego Zoo gets a new baby giant panda

A new giant panda cub has been born at the San Diego Zoo. Bai Yun, a 13-year-old giant panda, gave birth at 9:57 p.m. on Tuesday to a cub weighing four ounces (113.5 grams).

"Bai Yun immediately tended to her squawking infant," said Suzanne Hall, a panda research technician at the San Diego Zoo who observed the births of Bai Yun’s other cubs in 1999 and 2003. The cub is the second to be born in the United States this year. In Washington, Mei Xiang gave birth to a male panda cub at the National Zoo last month after artificial insemination.

According to Hall, early ultrasound images indicated Bai Yun was pregnant with twins. However, zoo personnel became suspicious that one fetus was no longer viable after veterinarians failed to detect a heartbeat in one cub last week. Bai Yun failed to give birth to a second cub Tuesday evening. "It is likely that the second fetus died in utero and was reabsorbed by her body," Hall said.

Panda behavioral researchers will be watching the pair 24 hours a day for three weeks to record and assess the mother-infant relationship. The new cub has not yet been named. The gender of the cub will be unknown until zoo staff can safely check.