“I’ve been crying all day,” said Holly O’Brien-Yao, 58, of Falls Church as she stood outside the roped-off panda compound just before noon. “I’ve been praying for something really wonderful to happen to me, and this does it.”
Anthea Higgins, 43, of Potomac, who was visiting the zoo with her children, Sean, 8, and Caroline, 6, said the panda birth was a “spectacular” happening.
In a chaotic world, “it’s a little piece of hope,” she said.
At a noontime news briefing, zoo officials said they have closed the panda house to let mother and cub bond in peace and quiet. The cub was born at 10:46 p.m.
The birth will probably ignite a fresh wave of panda mania, two years after the zoo’s beloved first cub, Tai Shan, who was born in 2005, was sent to a breeding program in China.
All cubs and adult pandas, in the United States by agreement, are the property of China.
Zoo scientists were not sure why Mei, 14, became pregnant this year.
She had been artificially inseminated April 29 and 30 after she and Tian Tian, the zoo’s 15-year-old male, failed to mate on their own.
Pierre Comizzoli, a zoo reproductive physiologist who performed the procedures with a Chinese colleague, said he used sperm from Tian Tian that had been frozen and stored.
It was from the same batch that delivered Tai Shan.
Comizzoli said he had been part of the team, directed by the late zoo reproduction scientist JoGale Howard, that assisted with the 2005 pregnancy done via artificial insemination but with fresh semen.
He noted that this year Mei went into heat in April, when giant pandas usually do so, instead of mid-winter, when she had inexplicably gone into heat the previous three years.
The zoo announced Aug. 20 that Mei had entered the final phase of her annual reproductive cycle — one that would conclude in 40 to 50 days, with or without a cub.
It is notoriously difficult to determine whether a giant panda is pregnant because the animal can exhibit many false signs.
In its quest for cubs, the zoo has focused intense research on panda reproduction. In December, local philanthropist David M. Rubenstein, co-founder and managing director of the Carlyle Group, a global asset-management firm, pledged $4.5 million to fund such research.
On Sept. 5, the zoo announced that it was getting an additional $400,000 from the Ford Motor Co. Fund to study panda health. Much of the funding will go toward upgrading the 18-year-old panda-cam system, the zoo said.
Last year, Chinese and U.S. officials agreed to extend the adult pandas’ stay in Washington for five years. The deal replaced a 10-year lease that expired Dec. 6, 2010. The new agreement expires Dec. 6, 2015.