Cobby, oldest male chimp in captivity in U.S., has died at 63 in San Francisco Zoo

The oldest male chimpanzee living in an accredited North American zoo died Saturday at the San Francisco Zoo & Gardens. He was 63.

The chimpanzee, named Cobby, had been a hand-reared performing chimpanzee before he was brought to the San Francisco zoo in the 1960s. Although the zoo said in a news release that the chimpanzee's cause of death hadn't been determined, the animal had recently been ill and zoo officials believe old age was a factor. The International Union for Conservation of Nature lists chimpanzees as endangered, and they are considered among the most at-risk primates in Africa due to hunting, habitat loss and disease.