Harmonically complex is unrelated (unless they do something like Tuvan throat singing), but the species thing is a good point.
Compare a parrot or a crow vocalizing. From that it seems some can control the amount of overtone or at least can use two different modes or something.
Seems almost like comparing humans whistling vs speaking or something (assuming whistling is closer to a pure sine tone).
Compare a parrot or a crow vocalizing. From that it seems some can control the amount of overtone or at least can use two different modes or something.
Seems almost like comparing humans whistling vs speaking or something (assuming whistling is closer to a pure sine tone).