Mating-call variation across a narrow hybrid zone between Crinia laevis and C. victoriana (Anura : Leptodactylidae)

Abstract

A transect was established across the eastern extreme of the zone of interaction between the two closely related, parapatric taxa, Crinia laevis and C, victoriana. In this area the range of C. laevis extends as a narrow salient surrounded by the range of C. victoviana. Analyses of mating-call recordings obtained at six localities along the transect suggest that the interaction may be described as a hybrid zone in which the recombination products are fitter than individuals of either parental taxon. In spite of the possibility of reduced conspecific gene flow to individuals of C. laevis at the interface, no indications of reduction of hybridization through reinforcing selection were detected. Because the hybrid zone now separates individuals of each taxon, the two taxa are prevented from directly interacting.