Smithsonian.com

Zoo officials confirmed late Tuesday via ultrasound and hormone analysis that giant panda Mei Xiang is not pregnant. Photograph by Mehgan Murphy

Mei Xiang, the Zoo’s Giant Panda, is not pregnant. Despite frequent news updates over the weekend, that Mei was exhibiting all the signs of pending motherhood—cradling toys and making a nest—it just wasn’t meant to be. Mei Xiang was experiencing a pseudopregnancy, the Zoo reported early this morning.

Zoo officials report that “female pandas almost always undergo a pseudopregnancy when they ovulate, but fail to conceive.”

In January when the young panda cub Tai Shan was making his last debut in public before his flight to China,  Mei Xiang came into estrus and was artificially inseminated. She had been left briefly alone for a possible interlude with her mate Tian Tian, but the pair just weren’t in the mood.

Staff intervention in panda sex is a critical step in the difficult process because the window of opportunity is quite narrow. Giant pandas ovulate just once a year and mating must take place during a prescribed two day period. On April 22, the Zoo announced that Mei’s progestagen concentrations signaled the start of a 24-hour pregnancy watch. As the progestagen levels declined over the weekend to their normal levels, Zoo researchers knew that it could go only one of two ways, a cub or a pseudopregnancy.

Mei Xiang is expected to return to her normal routines of eating and roaming playfully in her enclosure. The panda habitat, which had been closed to give Mei a little peace and quiet over the weekend, has reopened this morning. So visitors are welcome to stop by and commiserate.