The relationship of the Brown and Black-backed Treecreepers (Results of the Harold Hall Australian Expedition No.24)

Abstract

The typical form of the Brown Treecreeper Climacteris p. picumnus occurs in south-eastern Australia, a darker form with paler head markings C. p. melanota occupying the peninsula east of the Gulf of Carpentaria. Specimens from near Cardwell are intermediate, not faded, examples of melanora. Variation' occurs in C. p. picumllus, specimens from the north-east being slightly darker with slightly paler head markings. These four groups might form an interrupted cline. Alternatively, the north·eastern forms of picumnus might be regarded as intermediate. In either case it seems preferable to regard picumnus and melanota as forms of a single species.