Thylogale billardieriiTasmanian pademelon

Last updated:

Geographic Range

Red-bellied Pademelons, Thylogale billardierii, are native to Australia and Tasmania, but now are only found on Tasmania. Red-bellied Pademelons were once widespread and abundant on the mainland of Australia, but they have been extinct on the mainland since the early 1900s. Red-bellied Pademelons are still abundant on Tasmania and the larger islands of Bass Strait. (Johnson and Rose, 1995)

Habitat

Thylogale billardierii inhabit areas of dense vegetation, rainforest and wet forest. Thylogale billardierii will also inhabit wet gullies in dry open eucalyptus field. However, when in a clear area, they usually stay within 100 meters of forest shelter. (PBS)

Physical Description

Thylogale billardierii are short stocky marsupials. Adult males weigh about 7 kg, females only about 4 kg. Pademelons have a short tail and compact body that are useful for maneuvering through dense vegetation. Thylogale billardierii have soft fine fur that is dark brown to grey brown on the dorsal side (back) of the animal, and reddish brown or lighter brown on the ventral side (stomach). The males of Thylogale billardierii have a broad chest and forearms, which are factors that contribute to males being larger than females.(Parks and Wildlife Services of Tasmania)

  • Sexual Dimorphism
  • male larger
  • Range mass
    2.5 to 12 kg
    5.51 to 26.43 lb
  • Range length
    1 to 1.5 m
    3.28 to 4.92 ft

Reproduction

Thylogale billaridierii are polygynandrous. Occasional clicking can be heard in males chasing after females in oestrus. Immediately after birth, the female again comes into oestrus, but the blastocyst remains in embryonic diapause.

Like other macropodids, baby Thylogale billardierii nurse in the mothers pouch after a short gestation period. In Thylogale billardierii, pouch life is six and a half months, and the young are weaned from the mothers teat around seven or eight months. Thylogale billardierii are usually sexually mature around fourteen or fifteen months. Thylogale billardierri are solitary animals that come together for mating, and will occasionally share a feeding ground.

Thylogale billardierii reproduce in captivity year round, but in the wild 70% of births are in late autumn. The gestation period is 30 days. The young makes its way into the pouch immediately after birth, and attaches itself to one of four teats. If there are other siblings, the newly born joey will choose a teat not used by a sibling.

Immediately after birth, the mother again comes into oestrus and mates. The resulting embryo develops into the blastocyst stage, and then remains in embryonic diapause. If the current joey is lost or removed, the blastocyst is developed and born 27-28 days later. If the current joey develops naturally, it will be replaced on the night he leaves the pouch by a new young resulting from the activated blastocyst(Rose et al. 1999).

  • Breeding season
    autumn
  • Average number of offspring
    1
  • Average number of offspring
    1
    AnAge
  • Average gestation period
    30 days
  • Average gestation period
    29 days
    AnAge
  • Range weaning age
    6 to 12 months
  • Average weaning age
    8 months
  • Range age at sexual or reproductive maturity (female)
    14 to 15 months
  • Range age at sexual or reproductive maturity (male)
    14 to 15 months

The young of Thylogale billardierii are exclusively cared for by the mother, until they are weaned at around 7 months. (Rose et al 1999)

Lifespan/Longevity

The lifespan of Thylogale billardierri is around 5-6 years in the wild. There is unsufficient data for the lifespan in captivity. (PBS)

Behavior

Thylogale billardierii are mainly solitary animals that come together for mating and occasionally for feeding. There is no evidence however, that any further connection between individuals persists. Thylogale billardierii travel to a feeding spot (sometimes as far away as 2km) each evening at dusk and return to a bedding spot each morning. Daytime feeding is extremely rare. As many as ten individuals may come together for feeding; however, they scatter immediately when they sense danger. (Parks and Wildlife Services of Tasmania)

Communication and Perception

Food Habits

Thylogale billardierii mainly eat short green grasses and herbs, and they occasionally eat taller woody plants. Thylogale billardierii are nocturnal and feed at night close to the protection of the forest. (PBS)

Predation

Economic Importance for Humans: Positive

Thylogale billardierii has a soft, fine fur that is valuable to humans. The meat of Thylogale billardierii has little fat, and is palatable to humans. Thylogale billardierii only inhabit Tasmania, this fact has added increased interest in tourism. (Stranham)

Economic Importance for Humans: Negative

Thylogale billardierii avidly eat brush and foilage, sometimes competing with the livestock of Tasmanian farmers. This has been controlled recently by the installation of electric fences. (Statham 1994)

  • Negative Impacts
  • crop pest

Conservation Status

Even though Thylogale billardierii is currently very abundant and widespread in Tasmania. The species is harvested each year to ensure that the numbers remain controlled and abundant.(PBS)

Contributors

Adrienne Davis (author), University of Michigan-Ann Arbor, Kate Teeter (editor), University of Michigan-Ann Arbor.

Glossary

Australian

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

World Map

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

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

delayed implantation

in mammals, a condition in which a fertilized egg reaches the uterus but delays its implantation in the uterine lining, sometimes for several months.

ecotourism

humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.

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.

female parental care

parental care is carried out by females

fertilization

union of egg and spermatozoan

folivore

an animal that mainly eats leaves.

food

A substance that provides both nutrients and energy to a living thing.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

herbivore

An animal that eats mainly plants or parts of plants.

internal fertilization

fertilization takes place within the female's body

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.

nocturnal

active during the night

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

tactile

uses touch to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

References

Johnson, K., R. Rose. 1995. Pademelons, Thylogale. Pp. 394-396 in R Strahan, ed. Mammals of Australia. Reed Books.

PBS, "Tasmania, Land of the Devils" (On-line). Accessed October 5, 2001 at http://www.pbs.org/edens/tasmania/featured.html.

Parks and Wildlife Services of Tasmania, "Wildlife of Tasmania" (On-line). Accessed October 2 ,2001 at http://www.parks.tas.gov.au/wildlife/mammals/padem.html.

Rose, R., J. Horak, A. Shetewi, S. Jones. 1999. Pregnancy in a marsupial, the Tasmanian Pademelon (*Thylogale billardierii*). Reproduction, Fertility, and Development, 11(3) 1999: 175-182.

Statham, M. 1994. Electric Fencing for the control of wallaby movement. Wildlife Research, 21(6) 1994: 697-707.