Meeting Abstract
Among populations, songs or calls may represent evolutionary isolating mechanisms due to localized variation and preferences for familiar patterns or structure. Research on geographic variation has typically focused on male song, which tends to be more prominent and variable than female vocalizations in temperate species. Florida scrub-jays (Aphelocoma coerulescens, FSJ) are cooperatively breeding, non-migratory corvids that defend single-pair territories. Territorial females use a sex-specific ‘rattle’ call that has been characterized as being from one of three main regional dialects: the rapid rattle, the hiccup rattle, and the soft rattle. We hypothesized that FSJs differentiate between rattle call dialects, with the prediction that local dialects would elicit the most aggressive responses. We recorded rattle calls at Archbold Biological Station (Venus, FL; hiccup), Oscar Scherer State Park (Osprey, FL; hiccup), and Seminole State Forest (Eustis, FL; rapid) and conducted playback trials at ABS and SSF. At SSF, FSJs responded more aggressively to the local rattle type than either foreign rattle (p < 0.001). At ABS, FSJs responded most aggressively to the local hiccup rattle (p < 0.001), and showed a nonsignificant trend to respond more aggressively to the nonlocal, same-dialect rattle from OSSP than the foreign dialect (p = 0.056). Thus, in FSJs, local female dialects elicit stronger behavioral responses than foreign dialects, mirroring a common pattern seen in geographically variable male songs of other species. Analyses of population-level genetics in FSJs suggest the existence of several distinct genetic groups that roughly align with the distribution of rattle call dialects. Taken together, these results suggest an important role for female call variation on the population-level genetic structure of the species.
