Tiger dies at St. Louis Zoo

ST. LOUIS (AP) - The St. Louis Zoo announced Friday that a nearly 20-year-old Amur tiger named Kalista has died.

The zoo said in a statement that Kalista had been under treatment for age-related degenerate joint disease for several years.

She was euthanized last weekend when medical treatment was not sufficient to keep her comfortable and pain free.

She had been the oldest living female Amur tiger in the Association of Zoos and Aquariums' North American Species Survival Plan Program.

The average life span of a female Amur tiger is just over 14 years.