Al, 18 when he died Friday, had been at the zoo since 1995. He was brought there with his mother, Martha, who died in 2001, and his twin, Steve, who died in August.

Eileen Floyd, the development director, said Al had stopped eating after months of failing health, the Anchorage Daily News reported.

"It was just time," she said.

Al also appeared to miss his brother, Floyd said, occasionally making a special call and waiting for Steve to reply.

Amur tigers, living along the border between Russia and China, weigh up to 800 pounds, making them the biggest of the big cats. They are highly endangered, with only a few hundred believed to be living in the wild.

Al, his mother and brother came from the Philadelphia Zoo. The Alaska Zoo hopes to get two or three new tigers by the spring, the newspaper said.