Female Choice in the Midwife Toads (Alytes Obstetricans and a. Cisternasii)

Abstract

Abstract A previous study reported that large males had greater mating success than small males in two species of midwife toads. A behavioural mechanism that would explain such a pattern is sought. Dominant frequency is inversely correlated with male size in Alytes obstetricans and A. cisternasii. In both cases, two-speaker playback tests with synthetic calls show that females have a significant preference for calls with low frequencies. The results shows that female preference may impose directional sexual selection upon a static acoustic character that is correlated with male size. Male Alytes tend their eggs on land, but male size is not correlated with hatching success. Therefore female preference for larger males does not appear to directly increase female fitness.