Spatial ecology of numbats (Myrmecobius fasciatus) in multi-use forests: insights from new GPS tracking technology
Sian Thorn, Adrian F. Wayne, Renée C. Firman, Nicola J. MitchellContext
Understanding habitat selection and home ranges of threatened animals is important to their effective conservation. The numbat (Myrmecobius fasciatus), an endangered marsupial that has experienced extreme range contraction and now only persists in two small indigenous populations, is a species where more nuanced information on habitat selection would greatly benefit its management.
Aim
Investigate the spatial ecology of the numbat in the largest of these two remaining populations: the Upper Warren region of south-western Australia.
Methods
We collected 18 GPS datasets from 15 numbats (n = 13 females, two males) over an 18-month period between October 2019 and March 2021, to assess habitat use at a macrohabitat (landscape) and microhabitat scale.
Key results
Female home-range size varied from 11.2 to 53.4 ha, with a median value of 29.5 ha, whereas male home-range size was considerably larger (80.2 and 278.7 ha). Factors that increased the likelihood of habitat use by numbats at a macrohabitat (landscape) scale included more recent timber harvesting, proximity to roads, and loamy gravel soil type, whereas more recent fire and proximity to nearest surface water feature decreased the likelihood of habitat use. The presence of hollow logs was positively related with high-use areas by numbats at the microhabitat scale.
Conclusions
This study has advanced our understanding of how numbats utilise forested habitats and showed that they have mixed responses to land management activities. Future research could focus on more detailed understanding of habitat preferences found in this study, including an investigation of numbat habitat use in relation to the broad range of fire regimes, and the importance of hollow logs.
Implications
We recommend integrating these findings into conservation management strategies for the numbat, to ensure continuing availability of high-quality habitat for the important Upper Warren population.