A modern stocktake of 'a not-so-common possum': recent and unpublished records of the common brushtail possum (Trichosurus vulpecula) in arid north-west Western Australia

The common brushtail possum (Trichosurus vulpecula) is a medium-sized marsupial that was formerly widespread across Australia, but has suffered extensive declines in its range and population size, with significant loss in semi-arid/arid areas. In the northern semi-arid/arid areas in Western Australia (WA), little is known about the density and distribution of brushtail possum populations. Here, we report on modern and unpublished records of brushtail possums in north-west WA, focusing on the Pilbara region. Records were sourced from various agencies and online sources. Prior to this study, only 13 records from the mainland Pilbara Interim Biogeographic Regionalisation of Australia (IBRA) bioregion were publicly available. We uncovered 47 additional independent records, with 35 records since 2000, indicating that brushtail possums are persisting in low densities in the Pilbara bioregion. Most Pilbara possum records we found were located in riverine and rocky environments, correlating to environments that include caves and large Eucalyptus sp. The capture of these data fills an important information gap that will now be available in public data repositories. We recommend that targeted surveys and follow-up monitoring be conducted in northern WA to determine whether brushtail possums are declining in this region, as has been found elsewhere in northern and central Australia.