A regional survey of 253 forest sites on the southwestern slopes and adjacent highlands of New South Wales recorded a total of 530 animals from five species of nocturnal forest birds and nine species of arboreal marsupials. One additional species, the Squirrel Glider Petaurus norfoicensis, was tapped during supplementary searches. Elevation (climate) and best type were the major factors accounting for the distribution of this fauna. Minor environmental gradients included geology, the density of hollow-bearing trees, topography, logging intensity and fire. The patterns of landuse in the region contributed to interactions between elevation, forest type and management history (logging, fire and grazing) which restricted inferences about the habitat requirements of animals.
Forest types occurring at either end of the elevational (wet-dry) gradient (Alpine Ash and Box-Stringybark) were poorer in species than forests occurring at intermediate elevations (Alpine Gums, Wet Peppermint and Dry Peppermint). The Wet Peppermint forest type, which was the richest in species of nocturnal animals, has been deliberately selected in the past for conversion to pine plantations. The fauna of the region was generally more sparse and patchy compared to four other regions (northeastern and southeastern New South Wales, and northeastern and Central Highlands of Victoria) where similar studies have been undertaken. Numbers of large forest owls and the Greater Glider Petauroides volans were recorded less commonly than expected and may have declined in the region. The Common Brushtail Possum Trichosurus vulpecula was particularly abundant. This species and the Common Ringtaii Possum Pseudocheirus peregrinus appeared to maintain their numbers in small (<2 000 ha), isolated forest fragments.