Interspecies Communication

Project Koko uses interspecies communication — establishing a shared language — as a tool to understand the inner workings of the great ape mind. A shared language enables us to develop closer, more trusting, relationships with them, which in turn leads to deeper (mutual) understanding. It also empowers captive great apes to have more control over their environment, by being able to convey their wants and needs precisely to their caregivers. While many forms of interspecies communication are possible with great apes, sign language has been the primary vehicle used in Project Koko.

Sign Language

American Sign Language was selected as the primary language to teach Koko because of the success other researchers had with Chimpanzees. Koko has learned over 1000 signs and continues to learn and be creative.  Learn more


While gorillas are unable to “speak” like humans because of differences in vocal anatomy, they have a variety of natural vocalizations that express their emotional states and needs. Koko has developed some new ones.  Learn more

Gorilla Art

Gorillas Koko and Michael both developed an interest in painting from an early age; both gorillas have produced beautiful representational paintings that clearly express their individual personalities. Learn more

Other Great Ape Language Projects

Project Koko is the only ape language project with gorillas. However, there has been at least one ape language project with every other species of great ape —chimps, bonobos, and orangutans. Learn more