CALL DIFFERENCES BETWEEN PERIPHERAL ISOLATES OF THE GEOCRINIA-ROSEA COMPLEX (ANURA, MYOBATRACHIDAE) IN SOUTHWESTERN AUSTRALIA

Male advertisement calls are described for four species of Geocrinia f rom southwestern Australia. Geocrinia lutea is a peripheral isolate on the eastern edge of the range of G. rosea. Calls of G. rosea and G. l utea are similar, a single pulse repeated continuously, but G. lutea h as a higher variance in calling rate. Intraspecific differences across the ranges of G. lutea and G. rosea do not predict the differences se en between species. Geocrinia vitellina is a peripheral isolate on the eastern edge of the range of G. alba, and both produce a similar call consisting of a short pulse train. Their calls differ in pulse number , dominant frequency, and pulse rate. Call differences are not related to levels of genetic differentiation. Distribution patterns of the fr ogs suggest call structure differences have evolved in isolated, perip heral populations.