Mainland broad-toothed rat (Mastacomys fuscus mordicus) recovery after wildfire

Abstract

Wildfires are considered a major risk to the threatened broad-toothed rat (Mastacomys fuscus mordicus), a native murid rodent. Kosciuszko National Park is an important stronghold for the species, raising concern regarding the impact of the 2019–20 fires on populations occurring in this area. Sixty-two burnt sites known to be occupied by the species in 2016–17 were revisited. One year after the fires, little evidence of the broad-toothed rat was found, with its distinctive scats located at just 8% of sites. All these sites had some unburnt vegetation present. In contrast, 80.4% of 51 unburnt sites had evidence of the broad-toothed rat in both the pre- and post-fire surveys. Two years following the fire, scats were found at 42% of burnt sites, predominantly occurring within grassland (n = 23), with three in forested habitat. Three years following the fire, the scats were detected in 66% of sites, comprising 30 in grassland, 11 in forested gully and the first in lower slope shrubland. Based on the recovery trajectory, it is likely that in subsequent years (with the absence of fire or the adequate management of other competing threats) all remaining previously occupied sites may be re-populated.