As well as using their beard to communicate, bearded dragons also use other gestures such as arm waving and head bobbing. Arm waving is thought to be a way for bearded dragons to recognise others from the same species and is also seen as a submissive behaviour. Head bobbing is aggressive and usually done with a puffed up, darkly coloured beard!
In this species it is not just the boys that have beards. Girls have beards too! Girls will display the same behaviours as boys when using their beard to communicate.
We have one bearded dragon at Amazonia. His name is Ben.