Sound Pattern Recognition in Some North American Treefrogs (Anura: Hylidae): Implications for Mate Choice

SYNOPSIS. Playback experiments using synthetic sounds indicate that gravid females of the gray treefrogs (Hyla versicolor and H. chrysoscelis) and the green treefrog (H. cinerea) selectively respond to sounds on the basis of physical properties that show inter-individual variation in the calls of conspecific males. Although the specificity is adequate to differentiate among the signals of many males, this potential for mate choice may not be fully realized in acoustically complex situations such as natural breeding aggregations. Female selectivity in H. cinerea was less precise in four-speaker experiments than in two-speaker experiments. An analysis of female preferences with respect to a call property correlated with body size was only partially successful in predicting the size distribution of successful males in a natural population. Finally, the existence of other synchronously breeding species of frogs with similar calls may impose significant constraints on intraspecific mate choice, and female specificity with respect to some acoustic properties of mating calls is difficult to explain otherwise.