In the above photo, a young Michael is gesturing to Koko that he wants her to “come” closer to him. This is an example of a natural gorilla gesture.
All gorillas use gestures to communicate with one another. Over 100 unique gestures have been observed in use by free-living and captive gorilla groups. In fact all great apes uses gestures and repertoires have been found to overlap across species, including human infants.
So in captive settings, where gorillas are forced to live in close proximity to humans, and depend on them for sustenance and enrichment, why not take some time to learn some of their natural gestures. This is not mutually exclusive to teaching them some of our sign language (ASL). In fact, ASL can form a natural “bridge” to learning their language — as they learn more of our signs, they can use those signs to help translate their natural gestures. This can be a very enriching experience for all concerned.