Sminthopsis macrourastripe-faced dunnart
Geographic Range
Sminthopsis macroura, the narrow-footed marsupial "mouse", or the striped face dunnart, is found from central Western Australia to western Queensland and northern New South Wales (Nowak 1983)
- Biogeographic Regions
- australian
Habitat
Narrow-footed marsupial "mice" are found in dry areas (Nowak 1983).
- Terrestrial Biomes
- desert or dune
- savanna or grassland
Physical Description
Weight is sexually dimorphic in this species with females weighing on average 16 grams and males weighing on average 19 grams. Head and body length ranges from 70 to 120 mm, and tail length is approximately 55 to 130 mm. Coloration is buffy to grayish on the back and sides with white underparts. The feet are also usually white and the tail is either brownish or grayish. The genus Sminthopsis can be differentiated from other marsupial mice by skull and dentition features. Their feet are slender and they have a black stripe down the face - giving them their common name. The pads on the feet are striated and the hind part of the soles lack pads. Narrow-footed marsupial mice have a relatively well developed pouch for a dasyurid. One other striking physical feature is the tail; during times of abundant food, it will accumulate fat and become carrot shaped. (Nowak 1983, Lovegrove 1999)
- Other Physical Features
- endothermic
- bilateral symmetry
Reproduction
In a captive colony of S. macroura , the breeding season was found to last from June to February. These animals have an iteroparous life-history strategy. The following information was also obtained from captive colonies; it is not known from wild S. macroura. Females are polyestrous with one cycle lasting approximately 26.2 days. Ovulation occurs spontaneously. Time of gestation is 12.5 days and after birth the young are carried in the pouch for 40 days. Litter size can range from 1 to 8 young. Female striped face dunnarts have 8 mammae. If a female has only 1 or 2 young she may not rear them. After the young leave the pouch, they are suckled in the nest for another 30 days. Sexual maturity in females depended on when they were born. Those born early in the season matured at 86-159 days, while those born later in the same season matured at an earlier age. Individual male dunnarts are capable of breeding over long periods during the breeding season. Males do not appear to be sexually mature until the season after their birth. It has been found that the timing of mating and litter production corresponds to the period of maximum sperm production. Male S. macroura show a relatively low amount of sperm production when compared to other Dasyurid species. (Nowak 1983, Taggart 1997, Woolley 1990a, Woolley 1990b)
- Key Reproductive Features
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
Lifespan/Longevity
-
- Average lifespan
Status: captivity - 4.9 years
- Max Planck Institute for Demographic Research
- Average lifespan
Behavior
Dunnarts dig burrows or build nests made from grasses and leaves. The nests are often found in hollow logs or under bushes or tree stumps. They are nocturnal and mainly terrestrial. They move by means of a bipedal gait when traveling fast, but over shorter distances, they may walk quadrepedally.
In a similar species of dunnarts, individuals have a home range, but the borders and size constantly changes. Males do not show territoriality. Nest sharing was not common during the breeding season, but at other times up to 70% of the population shared nests in groups of 2 to 8. It is not clear if this is the same in S. macroura. S. macroura may enter daily torpor when food availability becomes unpredictable. (Nowak 1983, Lovegrove 1999)
- Key Behaviors
- motile
Communication and Perception
Food Habits
Dunnarts are insectivorous. They have also been known to eat small vertebrates like lizards and mice. Their prey is caught on the ground. S. macroura may store fat in its tail during periods of abundant food and can then use those fat stores when food is scarce (Nowak 1983).
Conservation Status
-
- IUCN Red List
-
Least Concern
More information
-
- IUCN Red List
-
Least Concern
More information
-
- CITES
- No special status
Contributors
Barbara Lundrigan (author), Michigan State University, Julie Harris (author), Michigan State University.
Glossary
- Australian
-
Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- chemical
-
uses smells or other chemicals to communicate
- desert or dunes
-
in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.
- endothermic
-
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
- motile
-
having the capacity to move from one place to another.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- tactile
-
uses touch to communicate
- tropical savanna and grassland
-
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
- savanna
-
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
- temperate grassland
-
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
References
Lovegrove, B., G. Kortner, F. Geiser. 1999. The energetic cost of arousal from torpor in the marsupial Sminthopsis macroura: benefits of summer ambient temperature cycles. Journal of Comparative Physiology B, 169: 11-18.
Nowak, R., J. Paradiso. 1983. Marsupialia; Dasyuridae; Genus SMINTHOPSIS. Pp. 40-42 in Walker's Mammals of the World. Baltimore: The Johns Hopkins University Press.
Taggart, D., L. Selwood, P. Temple-Smith. 1997. Journal of Zoology;London, 243: 725-736.
Woolley, P. 1990. Reproduction in Sminthopsis macroura (Marsupialia: Dasyuridae) II* The Male. Australian Journal of Zoology, 38(2): 207-217.
Woolley, P. 1990. Reproduction in Sminthopsis macroura (Marsupialia:Dasyuridae) I. The Female. Australian Journal of Zoology, 38(2): 187-205.