San Diego Zoo panda gives birth to 5th cub

SAN DIEGO -- Prized San Diego Zoo panda mom Bai Yun has given birth to her fifth cub, the zoo announced Wednesday.

The cub, born to 17-year-old Bai Yun (White Cloud), becomes just the 13th panda in the United States.

It was born at 4:58 a.m. Wednesday, zoo spokeswoman Jenny Mehlow said.

A second fetus had been detected, but Mehlow said it was probably absorbed in the mother's uterus.

The pink panda newborn weighed about 4 ounces and is about the size of a stick of butter. Its gender won't be known for about a month, Mehlow said, and it won't get a name for 100 days, in line with Chinese tradition.

Mom and cub will lead private lives for the next four months or so, but they will appear on the zoo's live Panda Cam, which can be watched online.

Bai Yun, who weighs about 300 pounds, was born in a breeding center in China and arrived in San Diego in 1996.

The zoo announced just last week that Bai Yun was pregnant, based on ultrasound tests.

The father is longtime consort Gao Gao, who has fathered three of Bai Yun's other cubs.

The number of cubs makes the pair one of the most reproductively successful panda couples ever in captivity.

Pandas are notoriously poor breeders — one reason their species is endangered — and females have only three days a year in which they can conceive. Only about 1,500 giant pandas remain in the wild, and around 250 live in captivity.

Bai Yun and Gao Gao meet only a couple of days a year. When Bai Yun enters her fertile periods, zookeepers make sure Gao Gao is there, sniffing her through a perforated gate zookeepers call a "howdy door" until her chirps and bleats indicate she's ready to get down to business.

Bai Yun gave birth to her first cub in 1999 through artificial insemination from her first arranged suitor, Shi Shi. Hua Mei was the first giant panda cub born in the United States after a decade of failed breeding attempts. She has had three sets of twins since returning to China in 2003.