Tympanum fluctuating asymmetry, body size and mate choice in female midwife toads (Alytes obstetricans)

We address whether fluctuating asymmetry (FA) in an external ear element is correlated with the accuracy of location of a sound source (synthetic male advertisement calls) by female midwife toads (Alytes obstetricans). Fluctuating asymmetry in the tympanum was measured in gravid females. We studied the relationship between FA, snout-vent-length (SVL), and precision in approaching an acoustic stimulus through playback tests. Female mass was negatively correlated with jump length. Tympanum FA was negatively correlated with the accuracy of location of a sound source. Thus, FA can play an important role in sexual selection by conferring an advantage in access to available males by females with low values of asymmetry.