Catching the Eye | Museum Victoria | CC BY 2.0

Broad-toothed mouse. Photo: Catching the Eye | Museum Victoria | CC BY 2.0

Broad-toothed mouse

Mastacomys fuscus
Vulnerable: Biodiversity Conservation Act 2016
Near Threatened: IUCN RedList (IUCN 2018)
Vulnerable: Environment Protection and Biodiversity Conservation Act 1999

The broad-toothed mouse is a native, chubby-cheeked mammal with long dense fur. They only exist in alpine and sub-alpine regions of south eastern Australia. They have a ringed tail and a gentle demeanor when handled.

Their distribution is highly fragmented due to clearing for roads, ski runs and building developments. These mammals rely on high rainfall, cool summers, cold winters, and a dense ground cover of grasses, sedges and shrubs. They live in a complex of runways through dense wet grass, sedge or heath habitat, usually within 15m of a water-course.

Feral horses occupying their small and specific habitat have the potential to out-compete the broad-toothed mouse for food (native grasses) and trample remaining nesting areas.

Broad-toothed mouse habitat is being impacted from browsing and trampling associated with the expansion of feral horse populations. The presence of feral horses is directly related to the decline of broad-toothed mouse populations. In broad-toothed mouse habitat sites severely impacted by feral horse impacts, no evidence of this species was found at all.



  • Green, K. and Osborne, W.S. (2003) The distribution and status of the Broad-toothed Rat Mastacomys fuscus (Rodentia: Muridae) in NSW and the ACT. Australian Zoologist 32: 229-237.
  • Schulz, M.. Green M., Worboys, G. L., Driscoll, D. and Crabb, P. (2018) Fish: impacts of feral horses —Stocky Galaxias, Feral Horse Impacts: The Kosciuszko Science Conference – Conference Abstracts, Australian Academy of Science, The Australian National University, Deakin University, Institute for Applied Ecology University of Canberra.