One of the oldest known Sumatran tigers in the U.S. has died at Zoo Atlanta.
Zoo President and CEO Dennis Kelly said Thursday the 21-year-old cat, called Sekayu, was euthanized after her health declined. Zoo spokeswoman Keisha Hines-Davis says veterinarians had been treating her for age-related health issues.
Sekayu came to Zoo Atlanta in 1993 after spending time at the Phoenix Zoo. She was born at the San Diego Zoo in 1987.
Zoo Atlanta has two other Sumatran tigers, which are considered to be the world's most critically endangered tigers. Researchers believe there are less than 400 left in the wild.
Zoo officials did not know how many of the tigers were in captivity.