Koko has a vocabulary of over 1000 signs (American Sign Language) most of which she learned during the first few years of the project. However, she continues to learn (and occasionally invent) new signs, to improve her ability to communicate with her caregivers.
In this 1-minute video clip, the sign for”butterfly” comes up in the course of a conversation between Penny and Koko and Penny demonstrates the sign for Koko. It is not a very easy sign for a gorilla to make, because of the thumb dexterity required to interlock her two hands. Nevertheless Koko makes a modest attempt and Penny encourages her to continue trying. Like most people, Koko responds well to praise.
The Gorilla Foundation will be sharing more of these ongoing “conversations with Koko” in a new web feature called KokoFlix, coming soon to koko.org.