I wonder if any here might wish to communicate without talking or writing? This is one way it's done. :-) In my own observations, over more than a quarter century, I have see the complex "language" of poses, movements, and color changes. It is a rich and nuanced form of communication. It is great to see that formal research is being done in this area. Someday, we may just be able to communicate and translate sufficiently well, to have real "conversations" with them! I find it fascinating as well, that they have the facilities to communicate vocally, but somehow never seem to use it. There have been only a half dozen times in all my relating that I noted any form of vocalization! http://www.wired.com/2015/01/lizard-visual-displays-order-matters/