Genetic Differentiation in the White-Browed Scrubwren (Sericornis-Frontalis) Complex (Aves, Acanthizidae)

Abstract

Genetic variation among the principal members of the white-browed scrubwren (Sericornis frontalis) complex was assessed by protein electrophoresis. A total of 31 enzyme systems, representing 49 presumptive loci, was screened electrophoretically and analysed by conventional genetic distance measures. Differentiation equivalent to species level was recorded between the Tasmanian form humilis and allotaxa on the Australian mainland. Among mainland forms (laevigaster in the north-east, nominotypical frontalis in the south-east and maculatus in the south-west) differentiation was at a much lower order, equivalent to that between subspecies. The small sample of frontalis isolated in the Mt Lofty Ranges (rosinae), nevertheless, exhibited marked divergence in proteins. Changes in alleles at the aldolase locus confirm that laevigaster and nominotypical frontalis intergrade secondarily, but between 27-degrees-S. (Brisbane-Dalby) and 23-degrees-S. (Rockhampton-Emerald), well to the north of previously postulated zones of introgression.