Production and perception of communicatory signals in a noisy environment

David A Luther* and R. Haven Wiley 2009 Biology Letters vol. 5 no. 2 183-187


Many animals communicate in situations that make it difficult to discriminate a species' signals from those of others. Consequently, coexisting species usually have signals that differ by more than the minimum required to prevent overlap in acoustic features. These gaps between signals might facilitate detection and discrimination of degraded signals in noisy natural conditions. If so, perception of signals should have broader scope than production. We investigated this possibility by studying song production and perception of two species of birds in an especially noisy environment, the Amazonian dawn chorus. With software developed for this study, we digitally synthesized songs of two species, as well as intermediate versions of their songs. Experimental playbacks of these synthesized songs to individuals of both species confirmed that perception (as indicated by responses) was broader than production of songs. We propose that broader perception than production of song promotes communication in noisy situations and limits the similarity between signals of coexisting species.

So this seems relevant, in the sense that they address the evolution of species recognition cues in a a noisy background. Except the authors don't try to put their findings along work done on signal evolution in other environments or types of signals, which is too bad.