The National Zoo announced Thursday that its adult female giant panda, Mei Xiang, failed to conceive after being artificially inseminated earlier this year, despite signaling over the past few weeks that she might have been pregnant. The zoo had closed its Panda House on September first after the 19-year-old bear exhibited a heightened sensitivity to noise, elevated hormone levels, and other signs indicative of either a pregnancy or pseudopregnancy.
In this case, it was the latter, which is not uncommon for female giant pandas in captivity. Mei Xiang underwent the insemination procedure on May 25 when the National Zoo’s biologists injected her with a sample collected from Tian Tian, the 20-year-old male with whom she has shared the panda exhibit since 2000. The pair previously produced three surviving offspring: Tai Shan, born in 2005; Bao Bao, born 2013; and Bei Bei, born 2015. Tai Shan and Bao Bao were both relocated to China, which owns all giant pandas and leases some specimens to zoos around the world, while Bei Bei will continue to reside at the zoo until around the time he turns four years old. All three cubs were conceived via artificial insemination—Tian Tian’s poor breeding abilities are well-documented.
Although the zoo isn’t giving up all hope on squeezing at least one more four-legged Instagram celebrity from its current breeding pair, Mei Xiang is nearing the end of her reproductive life cycle. Few giant pandas are fertile past age 20, though a Smithsonian press release is quick to note that “there are pandas who have had cubs when they were older than she is now.”
The Panda House will reopen to visitors on Sunday. Bei Bei is due to be shipped back to China some time in 2019.