Factors Influencing the Occurrence of Small Ground-Dwelling Mammals in Southeastern Mainland Australia

Abstract

We investigated the occurrence of small, ground-dwelling mammals (marsupial mice and rodents) across 128 forested study sites representing a stratified sample of the climatic, geological, and topographic features of far southeastern mainland Australia. We then developed statistical models for the occurrence of the agile antechinus (Antechinus agilis), dusky antechinus (A. swainsonii), and bush rat (Rattus fuscipes) based on various environmental attributes measured for each site. At a landscape scale, the climatic factor mean minimum temperature of the coldest month was an important explanatory variable for the bush rat, with the likelihood of its occurrence increasing with increasing temperature during that period. Sites with greater precipitation during the driest quarter of the year were more likely to support bush rats and the agile antechinus. At an on-site scale, protected slopes and gullies were more likely to support bush rats, and the occurrence of bush rats and the dusky antechinus increased at sites with a higher number of large fallen trees. In multiple-use forests, increasing the number of large fallen trees after timber harvesting may increase habitat quality for both the dusky antechinus and the bush rat, and retaining habitat on protected slopes and gullies also may be important for the latter species.