In the dense vegetation of temperate or tropical forests, communication processes are constrained by
propagation-induced modifications of the transmitted sounds. The presence of leaves, trunks and branches
induces important sound reverberation and absorption leading to diminution of the signal energy as well as
qualitative modifications. The aim of this paper is to briefly review the different strategies used by birds
to manage with these constraints. At the emitter’s level, an adapted emission behavior which takes into
account both the physical heterogeneities of the forest environment and the temporal variations of the acoustic
constraints, is especially useful to control the active space of signaling. The coding of information into
acoustic parameters that have different susceptibility to propagation constraints is also of great interest. At
the receiver’s level, an adaptive reception behavior (listening post) and a great tolerance to sound degradation
during the decoding process are the keys to an optimal communication process.