The original mammal fauna of the Pilbara biogeographic region of north-western Australia

The hills and ranges of the Pilbara contain large numbers of caves, but only a miniscule proportion of these holds mammal remains that can be used to reconstruct the original (i.e. pre-European) fauna. During two field seasons in 1985 and 2004, only 12 sites with bones were discovered. Material from three other sites lodged in the collections of the Western Australian Museum was also used. Thirty-six native mammal species plus the introduced House Mouse were identifi ed from cave surface remains. Compared with the fauna known from live-caught specimen records and the results of the Pilbara Biodiversity Survey, rodent species are comprehensively represented among the remains, dasyurid marsupials and bandicoots are moderately well represented, macropodoids are poorly represented, and bats (except two cave-roosting species) hardly represented at all. Results of this study indicate that the Central Rock-rat (Zyzomys pedunculatus), and probably the Golden-backed Tree-rat (Mesembriomys macrurus), originally occurred throughout the Pilbara ranges. Chuditch (Dasyurus geoffroii) is recorded from the Pilbara for the first time, suggesting that it may have occurred in the lowlands, while Northern Quoll (D. hallucatus) occupied the ranges. New records of Melomys burtoni and Pseudomys fieldi represent substantial extensions of geographic range. Overall, these results confirm the Pilbara as the western outpost of several northern mammal species, but show that the original fauna is less distinctive than previously thought, with a higher proportion of species widespread in the arid zone.