Beijing Zoo issued a statement on Sunday, announcing the passing of giant panda Gu Gu on Thursday.

"With heavy hearts, we announce that giant panda Gu Gu passed away at 2:09 am on Jan 16, 2025, ceasing to beat forever, at the age of 25 years and 4 months," the statement said.

Experts said in previous interviews that giant pandas enter their senior years after the age of 20, and at 25 years old, they are roughly equivalent to around a hundred human years.

The male giant panda was born in September 1999 and came to live at Beijing Zoo in 2004. In early 2024, due to old age, the zoo transferred Gu Gu to a non-display area.

Gu Gu was known for his gentle temperament and affectionately referred to as "elder uncle Gu" by visitors, according to the Zoo.

"Over the past five years, as Gu Gu aged, his physical condition and mental state gradually deteriorated," the statement said.

Since August, signs of abdominal fluid in Gu Gu began to show, accompanied by decreased appetite, slow movements and extended rest times, according to the zoo.

"The zoo promptly adjusted its diet, held several special meetings, invited experts in relevant fields to conduct a comprehensive analysis and discussion on Gu Gu's health condition and devised corresponding medical care measures," it said.

"Unfortunately, on the afternoon of Jan 15, 2025, Gu Gu's condition worsened. Despite the efforts of the zoo's professional team to save him, his life could not be preserved," the zoo stated.

According to expert examinations, Beijing Zoo tentatively concluded that Gu Gu's death was due to age-related physical decline, organ diseases and failure of the heart and liver.

"We deeply mourn and feel reluctant for Gu Gu's departure, cherishing the joyful moments spent with him. May Gu Gu rest in peace," the statement said.