Song repertoires and sensory exploitation: Reconsidering the case of the common grackle

Male common grackles, Quiscalus quiscula, sing one song type each, yet females prefer multiple songs. A pre-existing sensory bias explanation has been proposed to account for these results. Using phylogenetic analysis and published behavioural studies, (1) it is shown that the single-song condition of males is likely to be the derived state, and (2) it is suggested that female common grackles' preference for multiple songs may not be surprising given their natural history, and may in fact be a functional preference. The idea that the female preference is also ancestral and serves no current function, however, cannot be ruled out. (C) 1996 The Association for the Study of Animal Behaviour