Heath Mouse

A larger species of the Pseudomys, a genus of Australian rodents, with a body mass in a range from 55 to 90 grams (1.9 to 3.2 oz) for an average weight of 70 grams (2.5 oz). The head and body length of 95 to 120 millimetres (3.7 to 4.7 in) and the tail length of 85 to 100 mm (3.3 to 3.9 in) is always proportionally shorter. The pelage is densely furred and their body is comparatively stocky, the tail is well covered in dark brown hair at the upper side and a whitish colour below. Pseudomys shortridgei have a broad face and short muzzle, and rounded ears that are 14 to 16 mm (0.55 to 0.63 in) from the notch at the head. The fur colour of Pseudomys shortridgei is warm brown at the upper side, flecked with buff and blackish tones for an overall grey-brown effect. Under-parts of the pelage are distinctly paler, including the marked contrast at lower side of the tail. The regular hair of specimens are a slate colour for most of the length, and tipped with a clay brown tone at the upper quarter of the shaft. Dark guard hairs cover the upper portions of the body and give the heath mouse a fluffy appearance. The hair lengths are 17 mm (0.67 in) for the regular fur, and up to 22 mm (0.87 in) for the guard hairs. …

The population occurs in two geographically remote regions in the east and west of the continent. The habitat in the east is heathlands and heath-like scrub in treeless areas, the preferred vegetation type in southwest Australia is taller scrubland associated with mallee trees and climax heath assemblages in undisturbed areas. The population structure is responsive to fire, requiring a complex of climax vegetation—that has not been exposed to burning—and recently burnt areas to maintain an equilibrium in their relative abundance. The eastern distribution includes the Grampians region, and the arid open and sclerophyll vegetation of southwest Victoria in an area bounded by Dergholm, Nelson and Mount Clay. A population has been recorded on Kangaroo Island, but its current status is unknown. The western population is represented in isolated locations or conservation areas. including the Fitzgerald River, Lake Magenta and Dragon Rocks national parks and state reserves, and at the Ravensthorpe Range. The western and eastern groups may have become isolated several thousand years ago by a geographic barrier at the Great Australian Bight. The individual range of P. shortridgei is likely to vary with food availability and other circumstances, recorded as 0.75 hectares in one survey and up to 5 ha in a study using radio tracking. …

The species primary diet is herbivorous, consuming the green shoots of grasses when flowers and seeds are out of season, and fungivorous, eating the fruiting bodies of some fungi species. They reside in a nest at ground level or within a shallow burrow. The diet has been termed as generalist, and there is evidence of gut morphology that would favour the consumption of course plant and fungal material. Around one third of the diet is subterranean fruiting bodies, potentially nutritious truffle-like food in the soil. Seeds are a major component of their diet when they are most available, during the earlier part of the austral summer, then shoots and leaves of grasses and other monocot species. They search in soil for food in the seedbank to supplement their diet during winter. Pseudomys shortridgei is considered semi-nocturnal, usually active in the morning, retiring for the day, and resumes foraging in the later afternoon and evening. The animal is passive and trusting when handled in the field.