Starts with Darwin's The Expression of the Emotions in Man and Animals in 1872.
Communication is the basis of animal - animal interactions.
How animals exchange information is central to behavioral studies from mimicry to sexual selection to parent-offspring interactions. This is too general. Marler rejects the notion that a mouse rustling in the grass is communicating to an owl that is hunting it. Clearly there has been selection for the concealment of the mouse, but also for detection by the owl. Krebs and Dawkins went as far as to suggest that animal communication is really nothing more than one animal trying to manipulate another with signals evolving to this end.