Subspeciation in the Western Whipbird Psophodes nigrogularis and Its Zoogeographical Significance, With Descriptions of Two New Subspecies

Abstract

Geographical variation in the Western Whipbird Psophodes nigrogularis is reviewed by routine morphometric procedures. Four subspecies are recognised: nominotypical nigrogularis in extreme coastal south-western Australia, oberon in the mallee heaths of eastern south-west Australia, lashmari on Kangaroo Island and leucogaster in the Murray Mallee and on Yorke and Eyre Peninsulas, South Australia. Two of the subspecies (oberon and lashmari) are described as new. The presence of two fonns (nigrogularis and oberon) in south-west Australia raises questions about their taxonomic status and parallels the occurrence of other pairs of Bassian taxa in that region. Reconstruction of the evolution of such pairs identifies the highlands about the South Australian gulfs as an important refuge and source of speciation for Bassian birds during Quaternary and perhaps later Tertiary times. Implications for conservation are reassessed.