Data from: Variation in female mate preference in response to eavesdropping "interloper" males

Eavesdropping by conspecific males that are competing for mates has been demonstrated across a variety of taxa. However, few studies have investigated how eavesdropping may actually impact female mating decisions. Specifically, females may change their mating preferences based on whether the eavesdropping male varies in its phenotype (e.g., expression of condition-indicating secondary sexual characters or courtship vigor) relative to the male that initiated courtship. We examined variation in female preferences in the context of eavesdropping in the brush-legged wolf spider, Schizocosa ocreata. Female S. ocreata typically prefer males with large tufts and males that court at higher rates. In live mating trials, however, females preferentially mated with the males that courted first. It has yet to be investigated whether female preferences change when males of varying phenotypes are encountered sequentially, as might be expected in an eavesdropping context. We used video playback experiments to introduce females to a virtual courting male (initial male), followed by a second virtual courting male thirty seconds later (interloper male). We separately manipulated 2 aspects of male courtship (tuft size and courtship vigor) to measure female responses to an interloper male of lower, higher, or equal phenotypic expression. For both traits, females had an overall preference for the initial males. However, when the interloper male had large tufts or had high courtship vigor, female S. ocreata shifted the relative number of their receptivity displays. These results suggest that eavesdropping could be beneficial for interloper males, but the benefits may vary depending on the male’s phenotype.