Picture
The preferred habitat of the threatened Broad toothed rat

Broad toothed rats

Broad toothed rats (Mastacomys fuscus) are a native rodent endemic to south eastern Australia. Historically recorded from sea level to the highest mountain tops, this species has become restricted in range to alpine and mountain habitats. Habitat loss, predation from introduced predators and climate change have all been implicated in this species demise. It is recognised by state agencies has being a vulnerable species. 

Previous surveys throughout the ACT region in the 1980s and 1990s revealed a patchy distribution in montane bogs throughout Namadgi National park. No surveys had been conducted since the large fire that swept through the ACT in 2003, and little was known of its current distribution in the ACT. Dr.  Milner, an ACT Government ecologist, led a team of researchers into the alpine bogs of the ACT to hunt for this cryptic rodent, by conducting intensive surveys for signs of life. Namely, scats and runs.
Picture
Broad toothed rat scats
The team discovered that Broad toothed rats are present in several of the montane bogs throughout Namadgi National park. Hunting for rat tunnels and runs in the thick undergrowth, and identification of fresh scats allowed the team to confirm that rats were present in these bogs. Furthermore, the careful characterisation of vegetation within the bogs where broad toothed rats were found allowed us to perform habitat selectivity analysis, to reveal the preferences of broad toothed rats to specific types of vegetation.

Broad toothed rats displayed a clear preference for a few key plant species. Low and medium height heath is critical to providing good shelter for the rats to live in, while sedges make up a large part of their diet. Evidence of feral animals, such as fox and rabbit scats, and evidence of pig rootings (digging in the soil) all had a negative effect on the likelihood of detecting broad toothed rats. This study highlights the importance of montane bogs for broad toothed rats, and the need to conserve these habitats if this species is to remain in the ACT. Feral animal and weed control will be vital to ensure its long-term viability.
Milner, R., Starrs, D., Hayes, G., and M. Evans (2015) Distribution and habitat preference of the Broad-toothed rat (Mastacomys fuscus) in the Australian Capital Territory, Australia. Australian Mammalogy 37: 125-131 doi: 10.1071/AM14031