Add this to world records set Sunday: The panda Bai Yun gave birth to her sixth cub since arriving at the San Diego Zoo, considered the most surviving pandas born at a breeding facility outside the endangered species' native China.
Through a closed-circuit camera, nervous zookeepers, veterinarians and researchers had been on "panda watch" for several days. Because of Bai Yun's advanced age, the pregnancy was considered "high risk."
At 2:30 p.m. Sunday after an estimated three hours of labor, 20-year-old Bai Yun gave birth to a 4-ounce cub. Cub and mother appear to be doing fine, according to zoo officials.
The birth gives the zoo four pandas, more than any other zoo in the United States, officials said: Bai Yun, her mate Gao Gao, their 3-year-old son Yun Zi and now the unnamed cub, whose sex will not be known for several months.
Under a panda-loan agreement with the Chinese government, four other cubs born to Bai Yun have been sent to a panda research facility in China: Hua Mei, Mei Sheng, Su Lin and Zhen Zhen.
Five of Bai Yun's six cubs were the product of mating with Gao Gao. Bai Yun's first cub, Hua Mei, born in 1999, was the product of artificial insemination: Her first intended mate, Shi Shi, proved uninterested in mating. Shi Shi was replaced in 2003 by the more lusty Gao Gao.
Bai Yun, who arrived at the San Diego Zoo in 1996, may be at the end of her reproductive years, officials said.
Bai Yun and the new cub won't be on display for several months -- as they undergo a crucial "bonding period" -- but they will be visible on the Panda Cam on the zoo's website. Gao Gao and Yun Zi are kept away from Bai Yun and the cub.
The road to a panda birth is not easy.
For starters, the female panda is in season only one to two days a year. And it is not uncommon for male and female pandas to not like each other much (Bai Yun, for example, tried frantically to get Shi Shi interested in mounting her, without success).
Even after successful mating has occurred, a fertilized egg remains suspended within the female panda until something in the environment triggers the egg to implant. Just what acts as a trigger remains a mystery to researchers.
One fact, however, is not a mystery: Pandas, with their hypnotic black-and-white coloration, are considered the most popular animals ever displayed at U.S. zoos, giving rise to the phrase "charismatic mega-vertebrate."Bai Yun, who turns 21 on Sept. 7, delivered a cub Sunday afternoon.
The San Diego Zoo has had a love affair with giant pandas ever since two of the black-and-white bears came to visit in 1987. After years of red tape and tons of application paperwork, the Zoo and China agreed on a 12-year research loan of two giant pandas, Bai Yun and Shi Shi.
View the cam by clicking on the link below