Plants and Animals Index

Pilliga Mouse

Scientific name

Pseudomys pilligaensis

Description

The Pilliga Mouse has a head and body length of between 63mm and 79mm and a tail between 67mm and 79mm. They weigh between 10gm and 14gm with an average weight of around 12gm. Their hind foot is 18mm to 19mm long. The upper surface of their feet is pale pink with white hairs and they have bright pink on their ears. Pilliga mice have grey/brown fur on their backs which grades to russet on their sides. Their underbelly is white. Their tail is a similar colour to the rest of their body but it is darker on top and has a little tuft on the end.

Habitat

The Pilliga Mouse is only found in the Pilliga region of New South Wales , they have been recorded in the Merriwindi and Pilliga State Forests. The Pilliga Mouse's life is shaped by seasonal ebbs and flows. In the Pilliga State Forests there are plenty of Ironbark/cypress pine habitats that the Pilliga Mouse avoids. Instead the Pilliga Mouse seeks shrubby habitats dominated by Melaleuca and other heathy plants. A strong relationship was found between the Pilliga Mouse's preferred habitat and a low shrubby understorey in the state forests, but in the nature reserve the Pilliga Mouse was found also in more open areas.

The Pilliga Mouse is very sparsely distributed and appears to prefer areas with a sparse ground cover. Some evidence exists of dramatic population fluctuations by this species.

The Pilliga Mouse is restricted to an isolated area of low-nutrient deep sand which has long been recognised as supporting a distinctive vegetation type (Pilliga Scrub). Recent studies indicate that the Pilliga Mouse were found in greatest abundance in recently burnt moist gullies, areas dominated by broombush and areas containing an understorey of kurricabah (Acacia burrowii) with a bloodwood (Corymbia trachyphloia) overstorey. Consistent features of the latter two habitats were: a relatively high plant species richness; a moderate to high low shrub cover; and a moist groundcover of plants, litter and fungi. The gully where high rates of capture were encountered had an extensive cover by low grasses and sedges, with little shrub cover and large areas of ash-covered ground.

Whatever it is that makes the young regrowth so attractive to the Pilliga Mouse, an important link obviously exists between its survival and the periodic burning of its habitat. Perhaps equally important is the fact that there is always unburnt habitat that the mouse prefers and into which it can escape.

Behaviour

The Pilliga Mouse is nocturnal.

Pilliga mice are social rodents that live together in simple burrow systems, comprised of two entrances and nest chamber, lined with leaves, some 20cm to 30cm below the surface. In general the Pilliga Mouse will use the same burrow for up to six months; less in the warmer months. The Pilliga Mice are most social during the winter months, this may by for the warmth provided by others in the nest.

The diet of the Pilliga Mouse varies throughout the year. They eat mostly fungi during the winter months; most likely because it grows underground and easier to access from their burrows. Insects, green shoots and seeds are consumed more in the summer months.

The Pilliga Mouse breeds between October and February and the gestation period is 24 to 31 days. Pregnant mothers remain in the burrow after the other Pilliga mice (one year old or older) have left. She searches for the resources she and her young will need once she gives birth. The young will remain with the mother until the next spring when she will most likely be pregnant again.

Notes

The Pilliga Mouse was first identified in 1975. It has a very restricted distribution, and is known only from the Pilliga Scrub near Narrabri in NSW. It was first recognized as a species by science in 1980, at that time there were only 12 known members of this species in existence. It closely related to a group of similar-sized mice, the New Holland Mouse and the Delicate Mouse. Recent genetic work has shown that the distinctions between these three species is a little blurred.

Status and Threats

They are elusive, and until the reasons for their limited distribution and numbers are known, the Pilliga Mouse is on the vulnerable species list.

There are only two threats to the Pilliga Mouse; fire and predators. Owls are the only known predators to this species, after a fire the Pilliga Mouse is even more vulnerable because they lack shelter. (There is very little information available on the behaviour of this species, primarily due to a lack of specimen.)

References/Sources

Menkhorst, P. and Knight, F. A Field Guide to the Mammals of Australia , 2nd Edition 2004. Oxford University Press. ISBN 0 19 555037 4

Strahan, R. (Ed.) The Australian Museum Complete Book of Australian Mammals. Angus and Robertson Publishers, Sydney. 1983. ISBN 0 207 14454 0

Fox, B.J.Pilliga Mouse Pseudomys pilligaensis Fox and Briscoe, 1980. (pp 616-7) In: 'The Mammals of Australian' ed. by R. Strahan. Reed Books, Chatswood , New South Wales . 1995.

Weblink: Paull, David, NPA's Western Woodlands project Officer,NPA. The Pilliga Mouse-staying out of the line of fire.