Giant panda Bao Bao plays before leaving the zoo, in Washington D.C., the United States, Feb. 21, 2017. American-born giant panda Bao Bao will arrive in southwest China's Sichuan Province Wednesday night (Beijing time).(Xinhua/Yin Bogu)Giant panda Bao Bao plays before leaving the zoo, in Washington D.C., the United States, Feb. 21, 2017. American-born giant panda Bao Bao will arrive in southwest China's Sichuan Province Wednesday night (Beijing time). (Xinhua/Yin Bogu)

by Xinhua writer Xu Jianmei

WASHINGTON, Feb. 21 (Xinhua) -- "Goodbye, giant panda Bao Bao, we will miss you!"

In tears and smiles, the giant panda team at the Smithsonian's National Zoo in Washington gathered on Tuesday morning, sending the U.S.-born Bao Bao off to her new home in China.

Bao Bao, which means "precious" or "treasure" in Chinese, is the first female giant panda born in the U.S. national zoo and has won the hearts of numerous Americans since her birth three and a half years ago.

An animal keeper of Smithsonian's National Zoo weeps after watching giant panda Bao Bao leave the zoo, in Washington D.C., the United States, Feb. 21, 2017. American-born giant panda Bao Bao will arrive in southwest China's Sichuan Province Wednesday night (Beijing time). (Xinhua/Yin Bogu)An animal keeper of Smithsonian's National Zoo weeps after watching giant panda Bao Bao leave the zoo, in Washington D.C., the United States, Feb. 21, 2017. American-born giant panda Bao Bao will arrive in southwest China's Sichuan Province Wednesday night (Beijing time). (Xinhua/Yin Bogu)

Tens of thousands of panda fans from all over the country or even abroad flocked here to bid farewell to their sweetheart over the weekends, causing heavy traffic jams, panda keeper Jenny Spotten told Xinhua.

On Tuesday, the last day of her stay in the zoo, an exclusive farewell ceremony was held for Bao Bao who will fly to China to join a panda breeding program.

At around 8 a.m. (1300 GMT), Bao Bao came out from her den after a sound sleep, climbed up her favourite hemlock tree, munched on fresh leafy bamboo, stretched her black hind legs and even headstood for a while. Then the zoo superstar had a serene nap with her head on a rock under early spring sunshine.

Giant panda Bao Bao plays before leaving the zoo, in Washington D.C., the United States, Feb. 21, 2017. American-born giant panda Bao Bao will arrive in southwest China's Sichuan Province Wednesday night (Beijing time). (Xinhua/Yin Bogu)Giant panda Bao Bao plays before leaving the zoo, in Washington D.C., the United States, Feb. 21, 2017. American-born giant panda Bao Bao will arrive in southwest China's Sichuan Province Wednesday night (Beijing time). (Xinhua/Yin Bogu)

For the fluffy black-and-white panda, this was a typical normal morning just like what she had had before since she lived separately from her mother Mei Xiang about two years ago, said the keeper.

At about 10:30 a.m. (1530 GMT), Bao Bao left the zoo in a special crate. A FedEx aircraft carrying her took off at noon from Washington to China's southwestern city of Chengdu in a 16-hour nonstop flight.

She is travelling with a zoo keeper and a veterinarian, as well as her favourite treats including more than 22 kg of bamboo, 1 kg of apples, two bags of leaf-eater biscuits, cooked sweet potatoes and water.

"Aww she's so sweet! Wishing her safe travels back to China. She will be greatly missed. #ByeByeBaoBao," a fan tweeted after the zoo announced the panda cub's departure, which has been widely reported by U.S. major news outlets since last week.

"She's such an amazing animal and is absolutely beautiful. Everybody loves her," said Mariel Lally, another panda keeper.

"It's definitely sad to see her go, but almost really happy that I know she is going to do so well living there in China's giant panda conservation," Lally told Xinhua. "We will miss her."

Chinese Ambassador to the United States Cui Tiankai and Dennis Kelly, director of the U.S. national zoo, were on the scene bidding Bao Bao farewell. Kelly delivered Cui a sizable box of letters and postcards carrying blessings and longings from the fans.

"We will make sure Chinese people will keep these letters and Bao Bao will 'read' them when she grows up," Cui promised.

Following a Chinese tradition, the Chinese embassy brought dumplings to the zoo for panda fans last week, which was among a series of farewell events held in the zoo this month. Eating dumplings is a Chinese way of bidding farewell to a family member.

The Dujiangyan base of the China Conservation and Research Center for Giant Pandas located in Chengdu said earlier that it had already prepared a one-hundred-plus-square-meter enclosure for the U.S.-born cub, including a lounge and a playground.

The truck carrying giant panda Bao Bao leaves the zoo to airport, in Washington D.C., the United States, Feb. 21, 2017. American-born giant panda Bao Bao will arrive in southwest China's Sichuan Province Wednesday night (Beijing time). (Xinhua/Yin Bogu)The truck carrying giant panda Bao Bao leaves the zoo to airport, in Washington D.C., the United States, Feb. 21, 2017. American-born giant panda Bao Bao will arrive in southwest China's Sichuan Province Wednesday night (Beijing time). (Xinhua/Yin Bogu)

Upon arrival, Bao Bao will spend a month-long quarantine at the base, where she will adapt to local bamboo and Chinese-style bread, as well as the Sichuan dialect spoken by breeders, according to a Xinhua report from Chengdu.

Bao Bao was born in the U.S. national zoo during a live broadcast on Aug. 23, 2013, when she was just about the size of a stick of butter, weighing only 137 grams. Her weight now is about 93 kg.

The cub was "robust, fully formed," and was "a bright, healthy shade of pink," the zoo said at its website then. After the first cry from the cub, the 15-year-old mother Mei Xiang picked it up immediately and began cradling and caring for it.

It took the cub almost two months to open her eyes and one more month to take her first steps.

Following another Chinese tradition, the cub received her formal name when she turned 100 days old. The name "Bao Bao" was picked by a voting of global fans online. Over 123,000 votes were cast at the time.

The panda's mother Mei Xiang and father Tian Tian moved to the zoo in 2000 under a collaboration agreement between China and the United States. According to the agreement, panda cubs born in the United States to parents on loan from China must be returned to China.

China gave the zoo its first pair of pandas in 1972 to commemorate U.S. President Richard Nixon's historic visit. Since then pandas have remained a symbol of friendship between the two countries.

Giant pandas are among the world's most vulnerable and rare creatures, with a known population of only 1,600, mostly in China.