Male and Female White-crowned Sparrows Respond Differently to Geographic Variation in Song

Abstract

Abstract Bird song varies both between species and across geographic areas, and there is abundant evidence from playback experiments that both male and female birds are sensitive to these differences in song structure. Comparisons between the sexes are complicated by differences in the behavioral assays used for each sex: males are often tested in the field, i.e. in a natural setting, and females usually in the laboratory with hormone treatment. We performed a field playback experiment to male and female white-crowned sparrows on their territories to see if they made similar distinctions between songs. After we temporarily removed the females' mates from their territories, females approached and called significantly more in response to playback of conspecific song than to heterospecific song. Females gave the same responses to the local dialect as they did to songs containing phrases from a foreign dialect. In contrast, males gave significantly weaker responses to songs containing a phrase from a foreign dialect than they did to the local dialect. We discuss reasons why our results conflict with previous studies that found that females are more selective in responding to song than are males.