Bettongia penicillatabrush-tailed bettong

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Geographic Range

Widespread at the time of European colonization, Bettongia penicillata is now confined to south-west Western Australia (Christensen 1983).

Habitat

Bettongia penicillata appears to have been primarily an animal of open forests and woodlands. A common characteristic in all habitats occupied by the surviving populations in south-west Western Australia is a clumped, low understory of tussock grasses or clumped, low, woody shrubs (Christensen 1983).

Physical Description

The head and body length of B. penicillata ranges from 300-380 mm. Its tail length ranges from 290-360 mm. Its body is yellowish-grey above and paler below (Christensen 1983). The feet of B. penicillata are pale brown with bristly hairs not concealing the claws. Its long tail has a prominent black crest along the terminal third or two-thirds of the upper surface. The undersurface of its tail is pale brown (Lydekker 1894). Males and females are similar in appearence and no geographic variation has been reported (Christensen 1983).

  • Range mass
    1.1 to 1.6 kg
    2.42 to 3.52 lb
  • Average basal metabolic rate
    3.132 W
    AnAge

Reproduction

In B. penicillata, bredding is continuous (Christensen 1983). The gestation period is 21 days. A single altricial young is born, which has a short pouch life of about 98 days (Seebeck 1995). The young subsequently accompanies its mother at heel, sharing her nest until the next infant vacates the pouch and displaces it. While sharing the nest, the young continues suckling. A female gives birth to its first young at the age of 170-180 days and approximately every 100 days thereafter for the rest of its life of 4-6 years. Embryonic diapause is exhibited. (Christensen 1983).

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • sexual
  • Average number of offspring
    1
    AnAge
  • Average gestation period
    18 days
    AnAge
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    180 days
    AnAge

Lifespan/Longevity

  • Average lifespan
    Status: captivity
    18.8 years
    AnAge

Behavior

Bettongia penicillata is solitary except during courtship and mating and when females have young at heel (Seebeck 1995). They occupy distinct individual home ranges of about 20 to 40 ha, each including a nesting and a feeding area. Nesting areas are believed to be individually defended but the feeding areas of adjacent animals may overlap considerably. The daylight hours are spent in an elaborate domed nest made of grass or shredded bark, built over a shallow depression scraped in the ground, under a bush or other cover (Christensen 1983). Each nest measures about 150 x 200 x 200 mm and has a dry weight of about 500 g. Several nests are in use at any one time, but occupation of them is believed to be random (Seebeck 1995). The long tail of B. penicillata is used to convey nesting material. Bettongia penicillata forage from dusk until an hour or two before dawn. They are relatively slow-moving, except when disturbed, when they hop with their heads held low, backs arched, and tails extended (Christensen 1983).

Communication and Perception

Food Habits

Bettongia penicillata does not drink water or eat any green plant material. It is primarily fungivorous, its food consisting largely of the fruiting bodies of underground fungi, supplemented by bulbs, tubers, seeds, insects and resin, probably from Hakea shrubs. The proportion of fungal material in the diet is greatest in summer and autumn. Being deficient and imbalanced as a source of amino acids, fungus is not a good food for mammals but B. penicillata does not utilize it directly. Bacteria in the large sacculated fore-stomach digest the fungus, and these bacteria and their by-products, which constitute a more balanced diet, are themselves digested in the posterior part of the stomach and small intestine (Christensen 1983).

Economic Importance for Humans: Positive

N/A

Economic Importance for Humans: Negative

N/A

Conservation Status

Members of this speices are no longer present in Victoria, and are now found only in a few localities in south-west Western Australia. Recent Red Fox control at several sites in this region resulted in substantial population increases of B. penicillata (up to 400%) as well as increases in distributional range. It has been introduced to several islands in South Australia, but only two of these islands are capable of maintaining viable populations in the long-term (Seebeck 1995).

Other Comments

Where food resources are adequate, density of cover is the limiting factor on population size. Since the advent of European man, this limiting factor has assumed prime importance. Where it has not been excluded from its normal habitat by agricultural clearing or the impact of grazing animals, B. penicillata is now restricted by Red Foxes, although attempts have now been made to control these foxes. The last remaining populations in south-west Western Australia are in the Perup and Dryandra forests and the Tuttanning Reserve where the habitat is under active management directed to their survival (Christensen 1983).

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

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

Christensen, P. 1983. Complete Book of Australian Mammals. Angus & Robertson Publishers, Sydney.

Lydekker, R. 1894. Hand-Book to the Marsupiala and Monotremata. W.H. Allen & Co., Limited, London.

Seebeck, J. H. 1995. Mammals of Victoria. Oxford University Press, Oxford.

Thomas, O. 1888. Catalogue of the Marsupiala and Monotremata. Taylor and Francis, London.