It's a Girl! National Zoo Panda Cub's Sex Announced

The cub received its first neonatal exam on the morning of Aug. 25. (Image credit: Courtney Janney, Smithsonian's National Zoo)

The panda cub born last month at the Smithsonian's National Zoo in Washington, D.C., is female, zoo staff announced Thursday (Sept. 5).

Through genetic testing, Smithsonian scientists confirmed the sex of the cub, born on Aug. 23 to panda mom Mei Xiang. A paternity test also revealed that the baby bear's father is Tian Tian, the zoo's male panda.

After Mei Xiang failed to mate naturally with Tian Tian, staff resorted to artificial insemination. The female panda received fresh and frozen semen from Tian Tian and frozen semen collected in 2003 from Gao Gao, a male panda at the San Diego Zoo. [In Photos: Giant Panda Mei Xiang Gives Birth

A day after giving birth to the live cub, Mei Xiang gave birth to a stillborn, which was also a female sired by Tian Tian, the zoo said, adding that the cubs were fraternal twins.

The panda cub born at the National Zoo on Aug. 23, 2013, is female. (Image credit: Smithsonian's National Zoo)

Both mom and the tiny female cub appear to be healthy, but keepers are maintaining a close watch over the pair, mostly through a camera that's always turned on in the panda den. Zoo staff was able to give the newborn its first exam on Aug. 25, finding that she seemed to be breathing, nursing and digesting normally. The cub weighed about 4.8 ounces (137 grams). She will be named when she is 100 days old, in keeping with Chinese tradition.

Mei Xiang's first cub, named Tai Shan, was born at the zoo in 2005, but now lives at a facility in China. (All pandas officially belong to China under international law.) Her second cub was born on Sept. 16, 2012, but died about a week later, appearing to be underdeveloped.

Conservationists estimate that there are just 1,600 pandas left in the wild. Captive breeding is one way to help bolster the species' population numbers and boost genetic diversity, but it is notoriously difficult. Mei Xiang has only conceived through artificial insemination.

Two other panda cubs were born this year in the United States. Zoo Atlanta's female bear Lun Lun gave birth to twin panda cubs, both male, on July 15.

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Megan Gannon
Live Science Contributor
Megan has been writing for Live Science and since 2012. Her interests range from archaeology to space exploration, and she has a bachelor's degree in English and art history from New York University. Megan spent two years as a reporter on the national desk at NewsCore. She has watched dinosaur auctions, witnessed rocket launches, licked ancient pottery sherds in Cyprus and flown in zero gravity. Follow her on Twitter and Google+.