Hong Kong has welcomed two baby pandas which were conceived naturally after Ying Ying gave birth to a pair of twins, a male and female, on Thursday morning, becoming the world’s oldest first-time giant panda mum.

She bore the two panda cubs just one day shy of her 19th birthday, equivalent to 57 human years, with Ocean Park, which is home to her and partner Le Le, describing it as “a true rarity.”

The pair succeeded in mating naturally at Ocean Park in March. The park had kept her pregnancy a secret throughout the duration, only revealing the news almost 24 hours after her delivery.

“As a first-time mother, Ying Ying was understandably nervous throughout the process. She spent much of her time lying on the ground and twisting,” the park said in a statement late on Thursday.

Ying Ying and Le Le, the second pair of pandas given as a gift by Beijing to the city in 2007, failed to conceive despite several rounds of natural mating since 2011 and an artificial insemination procedure in 2023.

The unexpected news was announced by Chief Executive John Lee Ka-chiu on Thursday night, as he said it was particularly meaningful for the pair to give birth 한국을 to the twins in the year which marked the 75th anniversary of the People’s Republic of China.

“I want to express my gratitude to the country for gifting giant pandas to Hong Kong, which fully shows its care and support to the city,” Lee said.

“We would also like to thank Ocean Park’s team for taking good care of An An, Jia Jia, Ying Ying and Le Le over the years, as well as the experts from the China Conservation and Research Centre for the Giant Panda for their continuous support, which enabled Ying Ying and Le Le to give birth to the pair of cubs.”

Ocean Park said Ying Ying started showing pregnancy or pseudopregnancy symptoms including decreased appetite, increased rest time and changes in hormonal levels at the end of July.

It said the pregnancy was not “readily detectable” until Sunday when the park’s veterinary surgeons and experts from the panda center confirmed it via ultrasound scanning.