Animal Diversity Web

Ge­o­graphic Range

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

• Biogeographic Regions
• australian
  • native

Habi­tat

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

Phys­i­cal De­scrip­tion

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)

• Other Physical Features
• endothermic
• bilateral symmetry

• Range mass

  17 to 71 g

  0.60 to 2.50 oz

• Average basal metabolic rate

  0.189 W

  AnAge

Re­pro­duc­tion

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 number of offspring

  7

  AnAge

• Average gestation period

  30 days

  AnAge

• Average age at sexual or reproductive maturity (female)
  Sex: female

  285 days

  AnAge

• Average age at sexual or reproductive maturity (male)
  Sex: male

  285 days

  AnAge

Lifes­pan/Longevity

• Average lifespan
  Sex: male
  Status: wild

  0.9 years

  Max Planck Institute for Demographic Research

• Average lifespan
  Sex: female
  Status: wild

  3.0 years

  Max Planck Institute for Demographic Research

Be­hav­ior

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)

• Key Behaviors
• motile

Com­mu­ni­ca­tion and Per­cep­tion

• Perception Channels
• tactile
• chemical

Food Habits

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)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

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

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

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).

Con­ser­va­tion Sta­tus

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.

• IUCN Red List

  Least Concern
  More information

• IUCN Red List

  Least Concern
  More information

• US Federal List

  No special status

• CITES

  No special status

Other Com­ments

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).

Con­trib­u­tors

Ross Sec­ord (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor, Phil Myers (ed­i­tor), Mu­seum of Zo­ol­ogy, Uni­ver­sity of Michi­gan-Ann Arbor.

Ref­er­ences

Cock­burn, A. 1994. Adap­tive sex al­lo­ca­tion by brood re­duc­tion in An­tech­i­nuses. Be­hav­ioral Ecol­ogy & So­cio­bi­ol­ogy, 35(1): 53-62.

Cock­burn, A., K. Lazenby-Co­hen. 1991. Com­mu­nal nest­ing in An­tech­i­nus-stu­ar­tii mar­su­pi­alia dasyuri­dae. Aus­tralian Jour­nal of Zo­ol­ogy, 39(3): 273-284.

Cock­burn, A., K. Lazenby-Co­hen. 1992. Use of nest trees by An­tech­i­nus-stu­ar­tii a semel­parous lekking mar­su­pial. Jour­nal of Zo­ol­ogy (lon­don), 226 (4): 657-680.

Goldin­gay, R., S. Carthew, R. Whe­lan. 1991. The im­por­tance of non-fly­ing mam­mals in pol­li­na­tion. Oikos, 61(1): 79-87.

McAllan, M., T. O'Shea, J. Roberts. 1997. Sea­sonal changes in the re­pro­duc­tive anatomy of male An­tech­i­nus stu­ar­tii (Mar­su­pi­alia: Dasyuri­dae). Jour­nal of Mor­phol­ogy, 231(3): 261-275.

Newell, G. 1998. Char­ac­ter­i­za­tion of veg­e­ta­tion in an Aus­tralian open for­est com­mu­nity af­fected by cin­na­mon fun­gus (Phy­toph­thora cin­namomi): Im­pli­ca­tions for fau­nal habi­tat qual­ity. Plant Ecol­ogy, 137(1): 55-70.

Newell, G., B. Wil­son. 1993. The re­la­tion­ship be­tween cin­na­mon fun­gus (Phy­toph­thora cin­namomi) and the abun­dance of An­tech­i­nus stu­ar­tii (Dasyuri­dae: Mar­su­pi­alia) in the Bris­bane Ranges, Vic­to­ria. Wildlife Re­search, 20(2): 251-259.

Nowak, R. 1997. "Walker's Mam­mals of the World 5.1 On­line" (On-line). Ac­cessed Novermber 20, 1999 at http://​www.​press.​jhu.​edu/​books/​walkers_​mammals_​of_​the_​world/​marsupialia/​marsupialia.​dasyuridae.​antechinus.​html.

Stra­han, R. 1983. Com­plete book of Aus­tralian mam­mals: the na­tional pho­to­graphic index of Aus­tralian wildlife. Lon­don, Syd­ney, and Mel­bourne: Angus and Ror­ert­son.

Van Tets, I., R. Whe­lan. 1997. Banksia pollen in the diet of Aus­tralian mam­mals. Ecog­ra­phy, 20(5): 499-505.