Courtship song is more variable than calling song in the field cricket Teleogryllus oceanicus

Most cricket species have two types of acoustic signals used in mating: the calling song, which attracts females from a distance, and the courtship song, which is given only when a female has come in contact with a male. We propose that the calling song is used mainly for species recognition, while the courtship song may contain information about an individual male's quality. Calling song is therefore expected to be more stereotyped and less variable than courtship song. A comparison of coefficients of variation in the two types of song in Teleogryllus oceanicus supported this prediction, with five of eight song elements significantly more variable in courtship than in calling song. The remaining song elements did not differ in variability between courtship and calling song. The difference did not depend on the response of the female being courted, as similar results were obtained when males courted dead females.