Studies in Australian amphibia III. The limnodynastes dorslis complex (Anura : Leptodactylidae)

Abstract

The L. dorsalis complex is distributed extensively through coastal Australia, the Dividing Range, and parts of the western slopes and plains. Six subspecies have been described in the complex. Four of these are raised to species status and two additional subspecies are described. The complex thus comprises eight taxa in all: L. dorsalis, L. dumerili dumerili, L. d. insularis, L. d. grayi, L. d. variegatus, L, d. fryi, L. interioris, and L. terraereginae. The taxa were compared using two main criteria: adult male morphology and mating-call structure. Topotypic or near-topotypic samples of each form were obtained to ensure that comparisons were valid. L. dorsalis is restricted to Western Australia and is disjunctly allopatric to all the other forms in the complex. The eastern taxa have mainly parapatric distributions with several areas of contact between them. Where the range of L. d. dumerili comes into contact with those of L. d. insularis and L. d. variegatus, broad hybrid zones (up to 240 km wide) are formed. L. d. dumerili and L. d, grayi also appear to hybridize extensively. Where the range of L. d. dumerili contacts that of L. interioris a narrower hybrid zone (25-32km wide) is formed. Both L. d, dumerili and L. interioris have achieved sympatry with L, termereginae without any evidence of hybridization. The types of contact interactions can be related to the levels of divergence, particularly in mating-call structure, between the forms. Thus the calls of L, d. dumerili, L. d. insularis, L. d, grayi, and L. d. variegatus are all very similar. The call of L. interioris is quantitatively different to that of L. d. dumerili, with a lower dominant frequency,