Petrogale assimilisallied rock wallaby

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Geographic Range

Found only in northern Queensland, Australia (Strahan 1995).

Habitat

Rock dominated terrain in northern Queensland, Australia (Strahan 1995).

Physical Description

Physically, Allied rock-wallabies have large hindfeet, reduced forepaws, and large hindlegs compared to their arms. They stand upright and move bipedally. The coloration may depend on surrounding rock color. They are usually gray-brown on the body with lighter brown underneath and on their appendages, and darker paws and feet. The tail has a brush that becomes darker in coloration towards the end (Strahan, ed. 1995).

  • Range mass
    4.3 to 4.7 kg
    9.47 to 10.35 lb
  • Range length
    512 to 496 mm
    20.16 to 19.53 in

Reproduction

Allied rock-wallabies are usually found in facultative, long-term, monogamous pairs, although females may have extra-pair copulations. They breed continously throughout the year, yet certain times seem to be more common (Spencer et. al 1997).

  • Average number of offspring
    1
    AnAge
  • Average gestation period
    31 days
    AnAge
  • Range age at sexual or reproductive maturity (female)
    23 to 17.5 months
  • Range age at sexual or reproductive maturity (male)
    23 to 17.5 months

As with other marsupials, birth occurs early in the developmental process. At birth, young crawl to a pouch. They stay in the pouch on the teat for roughly 180 to 231 days. Sexual maturity occurs at 23 months for males and 17.5 months for females (Delaney 1997b).

Lifespan/Longevity

The Allied rock-wallabies may live over seven years in the wild (Delaney 1997a).

Behavior

Their home ranges are elliptical in shape and occupy 9 to 11 hectares, with extension during the dry seasons, presumably to find more food. Size of the home ranges is not sexually dependent. Allied rock-wallabies have a shelter site, usually a rock overhang, where they stay during the daytime (Horsup 1994). They are excellent climbers (Grzimek 1972).

Communication and Perception

Food Habits

Members of this species use darkness as a cover or shelter when foraging. Breeding pairs have been known to eat together, and feeding individuals also seem to prefer to be near to others with whom they are not breeding (Horsup 1994).

Predation

They are seldom threatened by predators.

Conservation Status

This species of rock wallaby has fairly stable population numbers, rarely reaching low levels. A possible threat to the species is introduced predators during a drought (Delaney 1997a).

Contributors

Sean Maher (author), University of Michigan-Ann Arbor, Ondrej Podlaha (editor), University of Michigan-Ann Arbor.

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.

fertilization

union of egg and spermatozoan

folivore

an animal that mainly eats leaves.

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

monogamous

Having one mate at a time.

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

sexual

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

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

terrestrial

Living on the ground.

year-round breeding

breeding takes place throughout the year

References

Delaney, R. 1997. Population dynamics of the Allied Rock-wallaby *Petrogale assimilis*: Implications for conservation. Australian Mammalogy, 19: 199-207.

Delaney, R. 1997. Reproductive ecology of the Allied Rock-wallaby, *Petrogale assimilis*.. Australian Mammalogy, 19: 209-218.

Grzimek, B. 1972. Grzimek's Animal Life Encyclopedia. New York: Van Nostrand Reinhold Company.

Horsup, A. 1994. Home range of the allied rock wallaby Petrogale assimilis. Wildlife Research, 21 (1): 65-84.

Spencer, P., A. Horsup, H. Marsh. 1998. Enhancement of reproductive success through mate choice in a social rock, *Petrogale assimilis* (Macropodidae) as reavealed by microsatellite markers.. Behaviorial Ecology and Sociobiology, 43: 1-9.

Strahan, R. 1995. The Mammals of Australia. Chatswood, NSW, Aus.: Reed Book.