A panda loaned to the US from China has returned to her home country after 20 years.
The 23-year-old panda Ya Ya left Memphis Zoo after the loan agreement expired this month.
On her arrival in Shanghai, social media users speculated about Ya Ya's health and treatment, as she looked bedraggled, missing patches of fur.
US and Chinese officials said she had been treated well and that her appearance was due to a medical condition.
Ya Ya the panda returned to China from US amid health speculation
At the start of the loan, she had been accompanied by Le Le, a male panda born in 1998 who died in February.
His death was found to be from a heart condition and his body was returned to China on the same flight as Ya Ya on Thursday.
The life expectancy of a giant panda in the wild is about 15 years, but in captivity they have lived to be as old as 38.
“After 20 years, Ya Ya has become like family, and she will be sorely missed by the Memphis Zoo staff and the local community,” the Tennessee zoo said in a statement on Wednesday.
“We wish her the best of luck in her new home.”
Memphis Zoo held a farewell party for Ya Ya earlier this month. The zoo has said the pandas were key to research and conservation projects and helped people experience some of Chinese culture.
A video of the elderly panda in quarantine in Shanghai, where she will stay for 30 days before returning to Beijing Zoo, where she was born, was shared online. It show the panda looking less than her best, with missing patches of fur.
Social media users responded with dismay at the footage.
Advocacy groups In Defence of Animals and Panda Voices had previously applauded the return of Ya Ya to China, saying the pandas had been suffering in the zoo setting.
But Memphis Zoo officials said the groups were spreading false information. Zoo president and chief executive Matt Thompson said Le Le and Ya Ya had been “two of the most spoiled animals on the planet”.
She began developing bald spots in 2006 and the shedding got worse in 2014, the Chinese Association of Zoological Gardens said.
Its experts and those at Memphis Zoo had tried a variety of treatments, it added.
“Ya Ya also lives with a chronic skin and fur condition which is inherently related to her immune system and directly impacted by hormonal fluctuations,” Memphis Zoo said.
The Chinese government also sought to reassure those concerned.
“During the giant pandas’ stay at the Memphis Zoo, they received good care from the zoo and great affection from the American people,” Chinese Ministry of Foreign Affairs spokeswoman Mao Ning said on Wednesday.
Pandas are commonly used as a diplomacy tool. Most recently, Suhail and Soraya were sent to Qatar ahead of Fifa World Cup 2022.
Decades of conservation efforts in the wild and study in captivity have saved the giant panda from extinction.
Its population has increased from fewer than 1,000 to more than 1,800 in the wild and almost 700 in captivity.
In 2016, the International Union for Conservation of Nature removed the panda animal from its endangered species list and re-classified it as “vulnerable”.
