Washington's National Zoo said Friday afternoon that panda matriarch Mei Xiang appeared to be in labor.
"Mei Xiang has become increasingly restless and started body licking — both signs that labor has probably started!" the National Zoo said on Instagram and Twitter. ”Our giant panda team is closely monitoring her via the Panda Cam for a cub’s arrival."
Mei Xiang has been spending most of her time indoors in a small den, where she has created a nest out of branches. Although the place looks tiny for a big panda, the zoo said giant pandas in wild give birth in small dens. “They stay in these dens for about the cub’s first 100 days," the zoo said on Instagram.
Earlier this week, the zoo, part of the Smithsonian Institution, posted an image from Mei Xiang's ultrasound that confirmed the pregnancy. “Keep your paws crossed!” the zoo posted, reporting that the fetus was “kicking and swimming in the amniotic fluid.”
Giant pandas at birth are about the size of a stick of butter. They're pink and hairless; the distinctive black and white fur markings of giant pandas come later.
Mei Xiang has had three cubs: Tai Shan, Bao Bao and Bei Bei. At age 4, all were transported to China under an agreement with the Chinese government.
At 22, Mei Xiang would be the oldest giant panda to successfully give birth in the United States. The oldest in the world gave birth in China at age 23.
The zoo said Mei was impregnated via artificial insemination, a process which was heavily affected by precautions over the COVID-19 pandemic. The procedure was conducted shortly after the entire zoo shut down on March 14. The zoo has since reopened on a limited basis.
The father is giant panda Tian Tian.
Rather than using a combination of stored frozen sperm and fresh semen, the zoo inseminated Mei Xiang only with thawed-out semen to minimize the number of close-quarters medical procedures. If successful, it would be the first of its kind in the U.S. using only frozen sperm.
Associated Press writer Ashfraf Khalil contributed to this report.