Koko was loaned to Patterson and subsequently remained with her , supported by The Gorilla Foundation .
Patterson originally cared for Koko at the San Francisco Zoo as part of her doctoral research after Koko developed a life - threatening illness .
Koko was loaned to Patterson and subsequently remained with Patterson , supported by The Gorilla Foundation .
Patterson originally cared for Koko at the San Francisco Zoo as part of her doctoral research after Koko developed a life - threatening illness .