Half a century of survey data reveal population recovery but persistent threats for the Vulnerable yellow-footed rock-wallaby in Queensland, Australia

Abstract

Abstract The record of mammal declines and extinctions in Australia raises concerns regarding geographically restricted and poorly known taxa. For many taxa, the existing data are insufficient to assess their conservation status and inform appropriate management. Concerns regarding the persistence of the subspecies of yellow-footed rock-wallaby Petrogale xanthopus celeris, which is endemic to Queensland, have been expressed since the 1970s because of red fox Vulpes vulpes predation, competition with feral goats Capra hircus and land clearing. This rock-wallaby is rarely observed, occupies rugged mountain ranges and, prior to our surveys, had not been surveyed for 25 years. We surveyed 138 sites across the range of this rock-wallaby during 2010–2023, including revisiting sites surveyed in the 1970s–1980s and locations of historical records. We examined occurrence in relation to habitat variables and threats. Occupancy and abundance remained similar over time at most sites. However, by 2023 the subspecies had recolonized areas in the north-east of its range where it had disappeared between surveys in the 1980s and 2010s, and three south-western subpopulations that were considered extinct in the 1980s were rediscovered. Recolonization and increases in abundance at numerous sites between the 2010s and 2020s are associated with declines in feral goat abundance, indicating dietary and habitat competition are major threats. Exclusion fences erected since 2010 could limit genetic exchange between rock-wallaby subpopulations whilst allowing domestic goats to be commercially grazed. Petrogale xanthopus celeris should remain categorized as Vulnerable based on these ongoing threats. Repeated monitoring approximately every decade should underpin management of this endemic taxon.