Morphometric variation and taxonomic status of brush-tailed phascogales, Phascogale tapoatafa (Meyer, 1793) (Marsupialia: Dasyuridae)

Abstract

This study details morphometric variation among the marsupial brush-tailed phascogale, Phascogale tapoatafa. The validity of phascogales from south-western and south-eastern Australia being classified as the single subspecies P. t. tapoatafa was questioned because of the substantial isolation of the south-west population; the northern Australian subspecies P. t. pirata was included in the inquiry. Discriminant function analysis performed on 18 skull characteristics (n = 50 skulls) produced separation between P. t. pirata, south-western P. t. tapoatafa, and south-eastern P. t. tapoatafa. Separation was also achieved between female phascogales from Victoria and those from New South Wales and southern Queensland, but not between the males of these two populations. Univariate tests identified significant size differences between the groups. Field data gathered on wild P. t. tapoatafa illustrate large size differences between phascogales of Victoria and south-western Australia. Phascogales from south-western Australia also exhibit a polymorphism in teat number (6, 7 or 8 teats; n = 72) that is not observed in other phascogales. This isolated population may represent a distinct taxon.