Habitat requirements of the mountain brushtail possum and the greater glider in the montane ash-type eucalypt forests of the central highlands of Victoria

The mountain brushtail possum, Trichosurus caninus Ogilby, and the greater glider, Petauroides volans Kerr, were surveyed by stagwatching hollow-bearing trees on 152 sites, each of 3 ha, in the montane ash-type eucalypt forests of the central highlands of Victoria in 1983-84 and 1987-89. The abundance of each species was correlated with measurements of vegetation structure and floristic composition by Poisson regression analysis, which is a form of generalised linear modelling. Significant explanatory terms in the Poisson regression model for the abundance of T. caninus were positive correlations with the number of hollow-bearing trees, the stand basal area of Acacia spp., and the occurrence of forests in gullies, and a negative correlation with the number of shrubs. The only significant variables in the model developed for the abundance of P. volans were positive correlations between the age of the stand and the number of hollow-bearing trees. These findings are discussed in terms of the known habitat requirements and other aspects of the biology of T. caninus and P. volans. The likely impacts on both species of present silvicultural practices in montane ash forests are also considered.