Meeting Abstract

77-4   14:15 - 14:30  Acoustic signal interference and reproductive character displacement during community assembly of Hawaiian Laupala crickets Hensley, NM*; van der Heide, W; Shaw, KL; Cornell University; University of Amsterdam; Cornell University nikohensley@gmail.com http://nicholaihensley.weebly.com

The acoustic niche hypothesis predicts that patterns of signal partitioning within a communication channel are due to reduced fitness from overlap with interfering noises. In animals that use acoustic communication as a secondary sexual trait - like the songs of many crickets species - such partitioning can further exacerbate reproductive isolation, potentially affecting biodiversity at both ecological and evolutionary levels. We seek to test if differences in the mating song between closely related populations of a Hawaiian swordtail cricket, L. cerasina, are due to the increased prevalence of congeners like L. pruna. Although our data show these species differ in their rate of song production, the primary characteristic females attend to during phonotaxis, field surveys reveal that individuals from a population with increased sympatry have faster songs while primarily signalling syntopically and sympatrically. In preliminary behavioral trials, female L. cerasina in simulated sympatry demonstrate slightly longer search times for mates, which may hint at a potential cost when co-occurring with heterospecifics. Further testing is needed to reveal if there are limits to such phonotactic discrimination in these crickets, and if acoustic interference can drive reproductive character displacement to produce phenotypic diversity across the landscape. As Laupala is renowned for its rapid speciation rate due to sexual selection, reinforcement of reproductive boundaries between species - like in the secondary sexual characteristics of mating song - may initiate cascade dynamics between populations within species because male traits and female preferences are tightly linked phenotypically and genetically.