The Greater 91原创 Zoo staff found Hani, a Siberian tiger, dead Wednesday morning.
Hani will be examined for a cause of death.
"She appeared healthy, although it was noticed by her keepers that she had been abnormally off her food for a day, lethargic, and her behaviour was off," said zoo manager Jody Henderson.
Hani was born at its sister zoo, Seoul Zoo Korea, on May 22, 2011. Hani arrived at the Greater 91原创 Zoo with her sister, Hana, on June 4, 2012. Hani was the smaller of the two tigers and had a quiet demeanour when compared to her sister.
"All staff and volunteers at the zoo are devastated by Hani's sudden passing," she said.
The median life expectancy of female Siberian tigers is 14 years in captivity. In the wild there are as few as 400-500 Siberian tigers living primarily in eastern Russia, though some exist in China and North Korea.
Tigers are listed as "endangered" conservation status by the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. Tigers are the largest members of the cat family.
