EmbedVideo(4474, 482, 304);Mei Xiang, the 14-year-old giant panda at the Smithsonian's National Zoo, gave birth to her second cub on Sept 16. The cub does not yet have a name and will not be on display for the public for about six weeks. Video by Smithsonian's National Zoo.
At 10:46 p.m. ET on Sept. 16, zookeepers monitoring the Smithsonian National Zoo's Panda Cam heard a squawk from inside the giant panda's den. It was the sound of a newborn giant panda cub, the second cub for mom Mei Xiang and dad Tian Tian.
The cub is hairless and about the size of a stick of butter, said Nicole MacCorkle, one of the animal keepers who works with the giant pandas. It won't develop the characteristic black and white markings for weeks, and they won't know the sex until they can bring it in for an exam.
For now, the cub is with its mom, and zookeepers are not interfering. The squawks and a few quick panda cam glimpses are the only clear observation that zookeepers have of the baby.
"It's pink and wiggly and very vocal," MacCorkle said.
"What a great day for Washington. What a great day for science," said Dennis Kelly, director of the zoo, at a press conference today.
It will be several weeks before the cub will be on display and 100 days before it receives a name, which is a Chinese tradition.
After giving birth, female pandas traditionally stay in their den nursing and caring for the cub for two weeks; they rarely venture out even for food or water. And like many new mothers, Mei Xiang hasn't been getting much sleep. Suzan Murray, chief veterinarian at the zoo, said they have observed her nodding off while cradling the cub, only to be awoken by its squawking.
Smithsonian's National Zoo director Dennis Kelly watches the Panda Cam monitors for a glimpse of the new cub. Photo by Smithsonian's National Zoo.
When it comes to reproduction, odds are stacked against pandas. Females only become fertile once a year and only then for about a 36-hour period, said Pierre Comizzoli, a reproductive physiologist. Giant pandas are solitary in the wild; the only time they seek out company is to mate.
After Mei Xiang and Tian Tian failed to mate successfully on their own, Comizzoli artificially inseminated Mei Xiang using frozen sperm from 2005 - that's the year the zoo's last panda cub Tai Shan was born.
With many failed attempts, zookeepers were relieved to find she her able to conceive again. "Nature is fantastic and full of good surprises," Comizzoli said.
Any time a panda mating is successful, the zoology community learns more about the species' delicate reproductive cycle, Comizzoli said. Most mammals produce progesterone when they are pregnant, but female pandas produce progesterone all the time, he said, making it difficult to tell if the spike in Mei Xiang's progesterone levels indicated a real pregnancy.
There are only 331 pandas in captivity and about 1,600 in the wild, according to the National Zoo. But successes like this give them hope, Comizzoli said.
"Ten or fifteen years ago, it was grim," he said. "But obviously that number will grow...it's a real success story."
