GPS-tracking reveals habitat use by the Hastings River Mouse ( Pseudomys oralis ) in recently burnt forest

The 2019–2020 Black Summer wildfires burnt ~74% of the range of Hastings River Mouse Pseudomys oralis leading to concern about the species, even though its grassy forest habitat is maintained by an uncertain fire regime. Given our poor knowledge of its fire response, we GPS-tracked P. oralis to assess habitat use in relation to previous fires, including the Black Summer fires (4 years earlier) and a low-intensity burn (6–18 months post-fire). GPS-collars were effective for showing nightly movements, but accuracy was variable, leading to the loss of ~33% of GPS fixes from the analysis. Short-term home ranges over 8–12 days averaged 1.4–1.5 ha (n = 12). Individuals used a variety of topographic positions in proportion to their availability. Home ranges encompassed regenerating vegetation 4 years after Black Summer fires, with the fire-severity mosaic used in proportion to its availability except at one site. There was little use of the low-intensity fire scar 6 months after fire, but use increased 18 months post-fire. Microhabitat use occurred mostly at random, except for greater use of areas near large logs and avoidance of fern, shrub, canopy and eucalypt regeneration cover. Although sample sizes were small, our results support patchy, low-intensity fires of a moderate frequency to maintain grassy habitat for the species.