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).
Perception Channels: tactile ; chemical
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.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
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).
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)
Antechinus stuartii are found in eastern and southeastern Australia, including Victoria, New South Wales, and Queensland. (Nowak, 1997; Strahan, 1983)
Biogeographic Regions: australian (Native )
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)
Terrestrial Biomes: forest ; scrub forest ; mountains
Average lifespan
Sex: male
Status: wild: 0.9 years.
Average lifespan
Sex: female
Status: wild: 3.0 years.
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)
Range mass: 17 to 71 g.
Other Physical Features: endothermic ; bilateral symmetry
Average basal metabolic rate: 0.189 W.
Antechinus stuartii have a single breeding season restricted to about three months, and produce one litter per year. Gestation lasts for 26-35 days and at least as many young as the number of nipples are usually born. With the absence of a pouch, young cling to the mother's underbelly and are dragged across the ground while she searches for food for about 5 weeks. Births usually occur within a period of about 2 weeks for any given population. Newborns are 4 to 5 mm in length at birth and weigh an average of 0.016 grams. They stay with the mother for about 90 days and reach sexual maturity in 9 to 10 months. The young leave the mother with the onset of winter. (Nowak, 1997; Strahan, 1983)
One of the more striking and unusual things about Antechinus is that all males die shortly after mating in their eleventh or twelfth month of life (McAllan, et al., 1997). This phenomenon occurs at the same time each year in any given population. Increased physiological stress results from aggression and competition between males for females, and heightened activity during breeding season. Increased stress levels apparently cause suppression of the immune system after which the animals die from parasites of the blood and intestine, and from liver infections. In the wild, many females die after rearing their first litter, although some do survive a second year. (Strahan, 1983; Nowak, 1997)
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual
Average birth mass: 0.016 g.
Average gestation period: 30 days.
Average number of offspring: 7.
Average age at sexual or reproductive maturity (male)
Sex: male: 285 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 285 days.
The brown antechinus (Antechinus stuartii), also known as Stuart's antechinus and Macleay's marsupial mouse, is a species of small carnivorous marsupial of the family Dasyuridae. The males die after their first breeding season, and the species holds the world record for being the world's smallest semelparous mammal.[3]
Antechinus stuartii is mostly light brown above, including the upper surfaces of its feet, and a lighter brown below and on its tail. Its body length is 93–130 mm (3.7–5.1 in) and its tail 92–120 mm (3.6–4.7 in), and it weighs 16–44 g (0.56–1.55 oz). Unlike in other members of Antechinus, no pale-coloured eye ring occurs. Antechinus agilis is similar in appearance and difficult to distinguish except by its distribution.[4]
The brown antechinus was only the third in its genus to be described and as such, until recently, has included species such as the agile antechinus (Antechinus agilis), the subtropical antechinus (Antechinus subtropicus), and the tropical antechinus (Antechinus adustus).[4]: 56 It has also been included itself with the yellow-footed antechinus as the subspecies A. flavipes burrelli.[5] It was described in 1841 by the entomologist William Sharp Macleay, who named the species in honour of his friend and fellow naturalist James Stuart, who had discovered the animal at Spring Cove (North Head) in 1837 while working as surgeon in charge of the Quarantine Station.[6]
The brown antechinus is mostly nocturnal and is arboreal, and females build large communal nests shared by many individuals. Like all antechinuses, the males die after their first breeding season (which lasts two weeks) as a result of stress and exhaustion.[4] The current accepted hypothesis to why this happens is that sperm competition drives increased male investment in reproduction.[7] Female brown antechinuses do not possess a pouch; the young must attach themselves to the teats (of which there are usually eight). Its diet includes beetles, spiders, amphipods, and cockroaches, although it is an opportunistic feeder.[5] The litter size is six or seven young.
The brown antechinus is found east of the Great Dividing Range in Australia, from southeastern Queensland to around Kioloa, New South Wales.[5] It is mostly found in forested habitats,[5] with dense lower ground cover and low fire frequency.[8]
The brown antechinus (Antechinus stuartii), also known as Stuart's antechinus and Macleay's marsupial mouse, is a species of small carnivorous marsupial of the family Dasyuridae. The males die after their first breeding season, and the species holds the world record for being the world's smallest semelparous mammal.
