How does a Beastmaster ranger's companion communicate? Telepathic link with the ranger? Empathic link with the ranger? Squawks and growls that only the ranger understands? Cultured British accent?
I figured that would be the answer. The ranger in my party has a falcon companion. "Falcor" gets called on to scout ahead pretty often, and the question of how much information he can relay to the party comes up from time to time.
I've been ruling that he uses squawk, pecks and the occasional line drawn in the dirt to get his point across, and I wondered if there was anything in the RAW on the topic.
I don't think they really do. They probably get used to working with their "master" like animals in the circus, but that's about it. The lion knows when you want him to dance, but he can't really help you finish your sudoku.