Sminthopsis longicaudatalong-tailed dunnart

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Geographic Range

The long-tailed dunnart, -Sminthopsis longicaudata-, is native to northwestern Western Australia where it inhabits rugged, rocky outcrops (Burbidge et al. 1995, Nowak 1999).

Habitat

Habitat is restricted to rugged, rocky outcrops of the western arid region of Australia (Burbidge et al 1995).

Physical Description

The long-tailed dunnart has an average head and body length of 80-100mm for males and 80-90mm for females. The most distinct characteristic for identification of -Sminthopsis longicaudata- is a tail that is more than twice the length of the body; in males tail length ranges from 200-210mm and in females tail length is between 180-200mm. The tail is mostly scaly with a few short hairs; the end of the tail has longer hairs that form a brush-like tip. The fur on the dorsal part of the body is gray, while the underbelly is pale cream to white in color. The legs and the feet are white; the feet being slender and having striated or granulated pads. The head is somewhat flattened in shape with a long snout (Burbidge et al. 1995, Nowak 1999).

  • Range mass
    15 to 21 g
    0.53 to 0.74 oz

Reproduction

There is no information on reproduction in -S. longicaudata- in the wild, but some studies have been performed on captive animals (Wooley and Valente 1986). Females are polyestrus, with estrous periods lasting from August through December (Burbidge et al. 1995, Wooley and Valente 1986). Estrous cycles last from 51 to 30 days, with each cycle shorter than the one previous to it (Wooley and Valente 1986). Parturition occurs between 17 and 19 days after mating, and the young are fully enclosed in the pouch for the first three weeks after parturition. The female's pouch contains six nipples (Wooley and Valente 1986).

The age at which an individual of this species reaches sexual maturity is unknown (Wooley and Valente 1986).

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • sexual

Behavior

Long-tailed dunnarts are nocturnal, terrestrial animals (Nowak 1999). Physical evidence suggests that they may be capable of climbing (Burbidge et al. 1995). Dunnarts dig burrows or build nests of grass and leaves in hollow logs and stumps (Nowak 1999) and in cold conditions may become torpid (Burbidge et al. 1995).

In captivity, -S. longicaudata- can be maintained in small groups if ample space and nesting sites are available. Females with litters have been recorded attacking adult males (Nowak 1999).

Communication and Perception

Food Habits

The diet of -S. longicaudata- is primarily insectivorous. The bulk of their diet consists of arthropods, spiders, roaches, centipedes, grasshoppers, flies, and various larvae (Burbidge et al. 1995). Occasionally lizards, mice, and other small vertebrates are consumed (Nowak 1999).

Conservation Status

In western Australia there appear to be only three wild populations of -S. longicaudata-, two occuring in national parks and the other in a nature reserve (Burbidge et al 1995).

Other Comments

Until 1981, -S. longicaudata- was only known from a few museum specimens. In June of 1981, nine individuals were captured from the wild, allowing for the study of living specimens to begin. There are still relatively little data available on the natural history of -S. longicaudata-, with most of the research having been conducted on captive animals (Wooley and Valente 1986, Nowak 1999).

Contributors

Barbara Lundrigan (author), Michigan State University, Melinda Girvin (author), Michigan State University.

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

World Map

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

References

Burbidge, A., N. McKenzie, P. Fuller. 1995. Long-tailed Dunnart. Pp. 146-147 in R Strahan, ed. Mammals of Australia. Washington, D.C.: Smithsonian Institution Press.

Hurriccki, J., K. Kinman, J. Koeppl. 1982. Mammal Species of the World. Lawrance, Kansas: Allen Press, Inc..

Nowak, R. 1999. Walker's Mammals of the World, volume 1. Baltimore: The Johns Hopkins University Press.

Wooley, P., A. Valente. 1986. Reproduction in -Sminthopsis longicaudata-: Laboratory Observations. Australian Wildlife Research, 13: 7-12.