An orangutan who communicated with researchers using sign language has died at an Atlanta zoo. Chantek was 39.
On its website, Zoo Atlanta says Chantek died Monday. The cause of death isn't known, but the zoo says veterinarians had been treating him for progressive heart disease.
Chantek came to the zoo in 1997 at the age of 19. He was born at Atlanta's Yerkes Language Research Center and spent nine years living with researchers at the
Zoo Atlanta says Chantek was given a "naturalistic" living environment with other orangutans once he arrived there.
A postmortem exam of the ape is scheduled to be performed.