AUDITORY TUNING AND CALL FREQUENCY PREDICT POPULATION-BASED MATING PREFERENCES IN THE CRICKET FROG, ACRIS-CREPITANS

We examined frequency tuning of the female's peripheral auditory system, the dominant frequency of the male's mating call, and population-based mating preferences in cricket frogs (Acris crepitans) to determine how the relationship between the mean call frequency and mean frequency sensitivity of the female's auditory system determines such preferences. Females could exhibit preferences for either local calls or foreign calls. In all instances in which there was a preference, females preferred lower-frequency calls, regardless of whether they were local or foreign. These patterns of female preference are consistent with data showing that females are tuned below the mean call frequency of their population. Tuning also explains differences in preference among females of the same population. Tuning is negatively correlated with body size, and within a population larger females preferred lower frequencies and smaller females preferred higher frequencies. Thus female preference will generate directional selection acting on male call frequency but will also contribute to variation in call frequency.