Giant panda gives birth to "precious" cub at U.S. national zoo, creating "moment of pure joy"

Giant panda Tian Tian is seen at the Smithsonian's National Zoo in Washington, D.C., the United States, Aug. 22, 2020. Mei Xiang was artificially inseminated in March this year with frozen semen collected from Tian Tian. Mei Xiang, who's of an advanced maternal age, gave birth to a cub at Smithsonian's National Zoo here on Friday. (Xinhua/Liu Jie)

WASHINGTON, Aug. 21 (Xinhua) -- It was a day of joy and excitement for giant panda lovers.

Mei Xiang, who's of an advanced maternal age, gave birth to a cub at Smithsonian's National Zoo here on Friday.

Animal care staff witnessed the birth at 6:35 p.m.(2235 GMT), according to the zoo. Immediately after that, Mei Xiang picked the cub up and "began cradling and caring for it."

"Giant pandas are an international symbol of endangered wildlife and hope, and with the birth of this precious cub we are thrilled to offer the world a much-needed moment of pure joy," said Steve Monfort, John and Adrienne Mars Director of the Smithsonian's National Zoo and Conservation Biology Institute.

"Because Mei Xiang is of advanced maternal age, we knew the chances of her having a cub were slim," Monfort said. "However, we wanted to give her one more opportunity to contribute to her species' survival."

The announcement came just hours after the zoo tweeted that it believed Mei Xiang had gone into labor.

"Giant panda Mei Xiang has become increasingly restless and began body licking -- both signs that labor has probably started," the zoo wrote.

Mei Xiang, 22, was artificially inseminated in March this year with frozen semen collected from Tian Tian, the zoo's male giant panda. Female giant pandas are only in estrus, or able to become pregnant, for 24 to 72 hours each year.

In late July, the female exhibited behaviors consistent with pregnancy or pseudopregnancy. Zoo veterinarians confirmed evidence of a fetus on an ultrasound earlier this month. During the procedures, they saw clear images of a developing skeletal structure and strong blood flow within Mei Xiang's uterus.

The zoo announced last week that Mei Xiang could go into labor any day, prompting a surge in the number of viewers on its popular "panda cams." The website crashed shortly Friday afternoon possibly due to high interest.

The panda team heard the cub vocalize and glimpsed the cub for the first time briefly immediately after the birth on Friday. A neonatal exam will be performed when keepers are able to retrieve the cub, which may take a few days. The sex of the cub will not be determined until a later date.

Mei Xiang is the oldest giant panda in the United States and the second oldest documented in the world to give birth. This is also the first time a zoo in the United States has experienced a successful pregnancy and birth via artificial insemination using only frozen semen. Based on data from scientists in China and other zoos with giant pandas, females can breed into their early 20s.

Chinese Ambassador to the United States Cui Tiankai extended his congratulations to Mei Xiang and the National Zoo on the birth of the new giant panda cub, the third he has welcomed here.

"For 20 years, Mei Xiang and her kids have been adorable witnesses of China-U.S. cooperation and a constant source of joy for the Americans," Cui wrote. "A precious gift at this unusual time."

Mei Xiang has given birth to three surviving cubs: Tai Shan, Bao Bao, and Bei Bei. They returned to China when they were four years old as part of the zoo's cooperative agreement with the China Wildlife Conservation Association.

The National Zoo in northwest Washington, D.C. reopened to visitors last month after months of closure due to the coronavirus pandemic. The panda house at the David M. Rubenstein Family Giant Panda Habitat is still closed to provide quiet for Mei Xiang and her cub.

Giant pandas, dubbed China's national treasure, mainly live in Southwest China's Sichuan Province as well as the neighboring provinces of Shaanxi and Gansu.

The latest census in 2014 found there were 1,864 giant pandas living in the wild, up from 1,114 decades ago. The number of pandas bred in captivity has reached 600 globally, China's National Forestry and Grassland Administration said late last year.