Stable directional sexual selection and repeatable choosiness for song preference in the Pacific field cricket Teleogryllus oceanicus.

Abstract

Choosiness, or how picky an individual is in mate choice, is key to both sexual selection and speciation. Yet the amount of phenotypic variation in choosiness and how that variation is partitioned among individuals remain largely unexplored. Here, using the Pacific field cricket Teleogryllus oceanicus, we dissect preference for two song traits, proportion of long chirp and interpulse interval. We subsequently quantify phenotypic variation in choosiness and investigate whether there is consistent individual variation in choosiness and whether choosiness for different song traits covary. Strikingly, we found that the overall shape and peak preference for proportion of long chirp remained similar to those reported in an earlier study from the same population more than a decade ago, providing evidence that directional sexual selection can be relatively stable over long time frames in wild populations. Further, we found moderate levels of within-individual repeatability in choosiness for both song traits, suggesting a substantial level of individual variation in choosiness. Interestingly, choosiness for the two song traits positively covaries, indicating that there may exist overall choosier and more permissive females in song preference.