Stabilizing and directional preferences of female Hyla ebraccata for calls differing in static properties

Female frogs of many species show preferences for calls with particular properties. This study focuses on female preferences in Hyla ebraccata for computer-synthesized calls that differ in pulse-repetition rate or dominant frequency. Both of these call properties are static acoustic: properties of advertisement calls of H. ebraccata (within-male coefficient of variation <5%). Females exerted directional selection on dominant frequency, preferring low-frequency calls (2960 Hz) to calls with the dominant frequency of the population mean (3240 Hz). Because size is negatively correlated with dominant frequency, female choice could explain size-biased mating success observed in natural populations. Females also exerted stabilizing selection on pulse-repetition rate, preferring calls with a pulse-repetition rate of the population mean (99 Hz) to calls with a pulse-repetition rate that was twice as fast (200 Hz). The results of this study show that female choice creates either directional or stabilizing selection on static properties of calls. (C) 1998 The Association for the Study of Animal Behaviour.