Macrotis leucuralesser bilby

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Geographic Range

The lesser bilby lives in central Australia (Bilbies 1982).

Habitat

Lesser bilbies can be found in woodlands, savannah, shrub grasslands, or deserts that are sparsly vegetated (Bilbies 1983).

Physical Description

Bilbies are sexually dimorphic, with males being larger than females. Body length of male bilbies ranges from 365-440 mm, female body length ranges from 320 to 390mm (Bright 1993). Lesser bilbies have long tails ranging from 115 to 275 mm in length, and a pouch that opens downwards and backwards. The upper surface of the body is a light color, usually gray, and the underparts are white. The tail is white, with a gray line extending to the rear of the body. Bilbies also have very long, pointed, rabbit-like ears. A unique characteristic of lesser bilbies are their feet, which bear three stout toes with curved claws, the remaining two toes are very small. Their hind feet posses only three toes. The first toe is made up of the fusion of digits 2 and 3, the second toe (digit 4) is very large, and the last toe (digit 5) is an average size, the first digit is missing (Bilbies 1983).

  • Sexual Dimorphism
  • male larger
  • Range mass
    300 to 1600 g
    10.57 to 56.39 oz
  • Average mass
    354 g
    12.48 oz

Reproduction

Lesser bilbies breed between the months of March and May (Bilbies 1983). The gestation period is 21 days. Lesser bilbies possess a pouch. Young remain in the pouch for 70 to 75 days where they suckle, they are attached to one of the mother's nipples during that time. Fourteen days after leaving the pouch the young begin to be weaned (Wombats 1997). Litter size is typically 1 to 3 newborns (Bilbies 1983). Mating occurs again 50 days after a litter is born (Schneider 1990).

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

Behavior

Lesser bilbies are terrestrial, nocturnal desert mammals (Schneider 1990). They sleep sitting up, unlike other animals. They squat on their hind legs, tuck their muzzle between their legs, fold their long ears over their eyes, and sleep (Bilbies 1983). Due to their poor eye sight, lesser bilbies rely on their keen sense of smell and hearing to capture food. Their main predators are introduced foxes and cats, birds of prey, monitor lizards, and predatory marsupials. Lesser bilbies are solitary, with a home range occupied only by a female, male, and their young. Lesser bilbies are distinguished by their digging abilities, they den in a network of spiral tunnels in sand dunes. These tunnels are about 9 feet in length and 5 feet in depth. The opening of the tunnel is concealed to prevent enemeies from entering the nest (Schneider 1990).

Communication and Perception

Food Habits

Lesser bilbies are omnivorous, feeding mainly on small insects, fruit, and seeds. Their diet consists primarily of ants, termites, beetles, larvae, seeds, fruits, and fungi (Schneider 1990). Bilbies do not need to drink water, the water they recieve from the fruit and seeds is sufficient (Wombats 1997). Their desert habitat is a harsh one and when food is scarce female lesser bilbies may resort to eating their young to survive (Schneider 1990).

Economic Importance for Humans: Positive

Lesser bilbies were once hunted by humans for their smooth, silky fur (Wombats 1997).

Economic Importance for Humans: Negative

None known.

Conservation Status

Lesser bilbies were once common but populations declined drastically as a result of trapping for pelts, predation by introduced foxes, and competition with introduced rabbits for forage and burrows. Lesser bilbies were last collected in 1931 and they are considered extinct (Schneider 1990).

Contributors

Angela Singh (author), West Windsor-Plainsboro High School, Joan Rasmussen (editor), West Windsor-Plainsboro High School.

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

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

1996. ""Lesser Bilby"" (On-line). Accessed August 5, 2000 at http://www.schoolworld.asn.au/species/lesbilby.html.

1997. "Wombats". Pp. 24420-2445 in Encyclopedia of Mammals, Vol.16. New York: Marshall Cavendish.

1983. Bilbies. Pp. 52 in Walker's Mammals of the World. 4th edition. Baltimore: Johns Hopkins University Press.

Bright, Jenny, 1993. ""Information on the Bilby and its Environment"" (On-line). Accessed (Date Unknown) at http.

Schneider, Ingrid, 1990. Bandicoots. Pp. 300-304 in Grzimek's Encyclopedia, Vol.1. New York: McGraw Hill Publishing Company.