Meeting Abstract
Intraspecific clines provide key insights into the mechanisms that mediate lineage divergence. We examine the extent to which premating reproductive isolation varies along a genetic and phenotypic cline of populations of red-eyed treefrogs (Agalychnis callidryas) in Costa Rica and Panama. Our study had two aims: first, to quantify premating reproductive isolation (RI) using female mate choice and, second, to examine the relationship between reproductive isolation and phenotypic and genetic distance. We assessed female choice using a two-choice Y-design enclosure in three populations (Gamboa, Panama; Manzanillo and La Selva, Costa Rica). Females from each population were presented with a choice between a local and non-local male stimulus. We tested 38-40 females per population; 18-20 trials were conducted with the local and one non-local male and 20 trials with the alternate non-local male. For the male stimulus, we used plasticine models that were painted to represent focal populations and mounted on a rotating platform to simulate movement. Models were paired with population-appropriate acoustic stimuli. Choice was documented within a 10-minute trial. Log-linear modeling showed that females preferred local males, but assortative mating was not clinal. We quantified RI in JMATING and quantified genetic and phenotypic distances in calls and color as Euclidean distance. RI does not vary with genetic or phenotypic diversity. We discuss our finding of non-clinal assortative mating in red-eyed treefrogs in light expected levels of reproductive isolation for intraspecific populations.
