Recognition of courtship song in the field cricket, Teleogryllus oceanicus

The courtship song of the cricket, Teleogryllus oceanicus plays an important role in inducing the female to mount the male, which is necessary for mating. The song consists of a short, amplitude-modulated chirp, followed by a long trill of constant intensity and high syllable rate. Using playback techniques, it was determined which physical parameters of courtship song are necessary and/or sufficient to evoke normal female mounting of muted, courting males. The higher harmonics of natural courtship song were neither necessary nor sufficient for the effectiveness of the song. The chirp component alone was sufficient to evoke normal levels of mounting, but the trill was only partially effective on its own. The conspicuous amplitude modulation of the chirp was not necessary to evoke normal responses. The results suggest that the high effectiveness of the chirp is due to its characteristic temporal pattern. As in other cricket species, the song repertoire of T. oceanicus also includes distinct calling and aggression songs, which contain chirps that are structurally similar to the courtship chirp. Both calling and aggression songs evoked normal mounting responses when played back in the context of courtship. (C) 1996 The Association for the Study of Animal Behaviour