Distribution assessment of the bare-nosed wombat (Vombatus ursinus) in Australia

Abstract

The bare-nosed wombat (Vombatus ursinus) is commonly distributed across the southeastern parts of Australia. However, their population abundance and habitat range have reduced due to a range of threats, including disease, human impacts, predation, and climate change. Local declines in wombat populations can lead to many ecological and biodiversity concerns due to their role of ecosystem engineer on environments. Previous studies have evaluated wombat population and distribution status in relation to specific threats and regions, but their distribution range and core habitats at a national scale remain unclear. The thesis aimed to produce a national-scale predicted habitat suitability map for the bare-nosed wombat and subsequently discuss spatial patterns under various environmental characteristics.

Long-term monitoring across broad spatial scales is limited by available resources because wombats are dynamic. Therefore, the study (Chapter 2) used the online open accessible database and species distribution model (MaxEnt) to better understanding their current distribution. A total of 36,210 data points collected from the government databases of each Australian state, Wombat Protection Society of Australia Incorporated, Atlas of Living Australia, the WomSAT citizen science tool, and 12 field sites across New South Wales were analysed. Highly suitable areas are mainly located within the Interim Biogeographic Regionalisation for Australia regions of the Sydney Basin, South Eastern Corner, and South Eastern Highlands, but is scattered overall, with limited predictions in Tasmania and the border between Victoria and South Australia. Soil (landscape and soil type) and land use were identified as the key variables influencing wombat presence. Wombats are primarily distributed in grazing land and protected areas, showing a preference for places with soil units of Mb2, Me1, and Mw1.

The thesis suggests assessing the appropriateness and effectiveness of protected areas in highly suitable areas and conducting long-term monitoring to advance wombat conservation. More field surveys should be conduct along the edges of the predicted habitat range to confirm the actual distribution limits. Moreover, implementing effective measures to mitigate human-wombat conflicts is essential for conserving wombats, especially in grazing land where wombat activity highly overlaps with human use.

Date of Thesis submission	2025
Original language	English
Awarding Institution	Western Sydney University
Sponsors	Australian Government Research Training Program Scholarship
Supervisor	Julie Old (Supervisor), Hayley Stannard (Supervisor) & Ricky Spencer (Supervisor)