Complex communication signals: the case of the Blue-black Grassquit Volatinia jacarina (Aves, Emberizidae) song. Part I--a structural analysis.

The song of the Blue-black Grassquit Volatinia jacarina is different for every individual and the structural differences between individuals are quite complex. Samples of songs from different Brazilian localities, as well as from Venezuela and Mexico, were studied through a comparative analysis of their sonograms. From the structural point of view, the results show a song composed of a single note that is compacted in a "window" between 2 and 13 kHz and rarely occupying more than half of a second.