The importance of calling song and courtship song in female mate choice inthe variable field cricket

Male field crickets produce calling songs, courtship songs, tactile signals and chemical signals. Although calling songs are known to play an importan t role in female mate choice, the importance of the other signals in mate c hoice is poorly understood. In the variable field cricket, Gryllus lineatic eps, females select mates, in part, based on variation in male calling song , Females prefer higher chirp rates, a trait which is partially dependent o n male nutrient intake, and females prefer longer chirp durations, a trait which appears to be independent of male nutrient intake. We tested whether females also have preferences based on variation in male courtship song, an d whether the structure of male courtship song varies with nutrient intake. First, we reexamined female preference for calling song chirp rate. Then, we examined: (1) female preference based on courtship song chirp rate; (2) the relative importance of calling song and courtship song chirp rate; (3) the nutrition dependence of courtship song chirp rate; and (4) the correlat ion between calling song and courtship song chirp rate. As reported previou sly, females preferred higher calling song chirp rates, and in addition, pr eferred higher courtship song chirp rates. Females were more likely to swit ch from a speaker broadcasting more attractive calling song to a speaker br oadcasting less attractive calling song when the attractive calling song wa s associated with an unattractive courtship song than when it was associate d with an attractive courtship song. Preferences based on courtship song ma y thus cause females to alter the choices that they made based on calling s ong. Males that received greater nutrients did not produce higher courtship song chirp rates. There was no correlation between calling song and courts hip song chirp rate. As a result, the two traits may provide information to females about different aspects of male quality. (C) 2000 The Association for the Study of Animal Behaviour.