Antechinus stuartii
brown antechinus

Antechinus stuartii are found in eastern and southeastern Australia, including Victoria, New South Wales, and Queensland. (Nowak, 1997; Strahan, 1983)

Antechinus stuartii prefers wet sclerophyll forest with dense ground cover and an abundance of fallen trees in which to build nests. They usually stay on the ground, but may adopt a more arboreal lifestyle in drier areas, or where they occur sympatrically with Antechinus swainsonii, which lives on the ground. Population densities range from less than one to eighteen per hectare. Outside the breeding season males and females have their own foraging ranges. The availability of habitat may be influenced by foresters that "ring" trees leaving the trunk and major branches to rot, which provides nesting sites (Cockburn and Lazenby-Cohen, 1992). (Nowak, 1997; Strahan, 1983)

There is sexual dimorphism in size. Weight ranges from 29-71 g in males and 17-36 g in females. Average weight is 35 g for males and 20 g for females. Body length ranges from 150-250 mm in males, and 139-220 mm in females (Strahan, 1983).

Antechinus stuartii have short, dense, and somewhat coarse fur. Their back and sides are a uniform grayish-brown while the underbelly is lighter colored. The overall appearance is similar to placental mice with a long pointed head, elongate, plantigrade hind feet, a pink nose, and a tail length almost as great as body length. The tail is moderately furred, eyes are dark brown, and ears are relatively large. Females lack a pouch, instead they have a variable number of exposed nipples. The number of nipples varies by habitat. Females with 6 nipples live in the wettest areas and those with 10 nipples live in the driest and highest areas. Males are 20 to 100 percent heavier than females. (Strahan, 1983; Nowak, 1997)

During warm parts of the year individuals live in solitary nests and occupy their own home ranges. As temperatures drop, however, individuals of both sexes cluster together in nests with up to 18 animals. The nests are not stable and individuals may change nests. 28 females and 24 males were observed using a single nest over one winter (Cockburn and Lazenby-Cohen, 1992). Females typically nest alone to rear young and may split their offspring between nests in different trees. To cope with winter stress individuals may slip into a torpor for a few hours to lower their metabolic requirements. Males leave their foraging ranges when mating season begins and group together in all-male nests during most of the night. Females remain solitary, but make excursions to the male aggregations. During mating season males become vocal, emitting staccato chirps, losing much of their caution, and becoming highly aggressive. (Nowak, 1997; Strahan, 1983)

The diet of Antechinus stuartii consists primarily of invertebrates, particularly beetles, spiders, and cockroaches. Their diet also includes smaller amounts of vertebrates, such as placental mice, as well as plant material and flower pollen (Van Tets and Whelan, 1997). A. stuartii are voracious predators and have a high metabolism. During winter they will consume as much as 60 percent of their weight in arthropods each day. They typically hunts at night but may be active during the day, especially during times when food is scarce, such as winter months. (Strahan, 1983; Nowak, 1997)

A possible correlation between Antechinus stuartii and the distribution of a pathogenic soil fungus (/Phytophthora cinnamomi/) was reported by Newell and Wilson (1993). P. cinnamomi can have devastating effects on plant communities such as the forests, woodlands, and heathlands of Australia (Newell, 1998).

A. stuartii may be important in the pollination of some Australian flowering plants (Goldingay et al., 1991).

Antechinus stuartii is generally not thought to be under any serious threat from humans or others, and is found in abundance in many areas. Some populations have been reduced, however, by predation from domestic cats (Nowak, 1997; Strahan, 1983). IUCN (1999) listed species decline as less than 10 percent and placed it in its "lower risk" and "least concern" categories.

A peculiar behavior of mothers is that they will deny milk to male offspring, preferring to wean females. Mothers also commonly eat their young, at least in captivity (Cockburn, 1994).