Dorcopsulus macleayiPapuan forest wallaby

Geographic Range

Papuan forest wallabies, Dorcopsulus maclaeyi, are endemic to southern New Guinea. This species is restricted to the rain forest near Port Moresby on the south coast of south-eastern Papua New Guinea. (Gilmore and Stonehouse, 1977)

Habitat

Papuan forest wallabies utilize cover and roaming space within the dense forests of New Guinea. They prefer dry areas that are heavily covered by tall trees and have rich floor vegetation. However, expansion of the broad plains containing savannah woodland and grasslands (maintained largely by periodic native burning) has pushed Papuan wallabies to move to higher elevations (1200 to 1300 m) in the forest. (Australian Marsupial and Monotreme Specialist Group, 2004; Gilmore and Stonehouse, 1977)

  • Range elevation
    1,200 to 1,300 m
    to ft

Physical Description

Dorcopsulus macleayi is the smallest marsupial in its genus. Pelage is a general brownish-grey and it is lighter ventrally. The tip of the tail is nearly bare and is white in color.

The skull is smaller, shorter, and broader in comparison to the other members of its genus. Head and body measure 490 mm. The tail averages 320 mm, and the hind foot is 115 mm. Individuals weigh between 3 and 5 kg. (Lydekker, 1896; Oldfield, 1888)

The dentition of D. macleayi is characterized by a pair of incisors that are small, light, and that do not touch each other. The canines are short and slender, whereas the molars are broad, evenly oval, and shorter than other Dorcopsulus. (Oldfield, 1888)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    3 to 5 kg
    6.61 to 11.01 lb
  • Average length
    490 mm
    19.29 in

Reproduction

Both male and female Papuan forest wallabies grow to about the same size and mature sexually about the same time. Mating is typically polygynandrous. Males commit fewer resources than females to the production of each offspring. Males engage in little pre-mating behavior and increase their chances of producing offspring by mating with as many females as possible. (Gilmore and Stonehouse, 1977; Renfree and Tyndale-Biscoe, 1987)

Breeding of Papuan forest wallabies occurs mostly in late January and early February. Reproduction is apparently related to female physiological condition. Because females invest so much energy in reproduction, a female will only enter estrus if she has enough energy and resources to successfully rear her offspring. (Gilmore and Stonehouse, 1977; Renfree and Tyndale-Biscoe, 1987)

As is true of all marsupials, the young are born after a short gestation. At birth, young are altricial. They complete their development inside their mother's pouch. Gestation is reported to last 21 days. Weaning probably occurs when the young leave the pouch at about 18 months of age. Of two records of females with offspring, one female had two young in the pouch, another had only one pouch young. Based on this, it is likely that only one or possibly two offpsring are produced at a time. Reproductive maturity is reached around the age of 2 years. (Gilmore and Stonehouse, 1977; Nowak, 1999)

  • Breeding interval
    Papuan forest wallabies breed once per year.
  • Breeding season
    Breeding season occurs in January and February.
  • Average number of offspring
    1
  • Average gestation period
    21 days
  • Average weaning age
    18 months
  • Average age at sexual or reproductive maturity (female)
    2 years
  • Average age at sexual or reproductive maturity (male)
    2 years

The gestation period is about 21 days. Birth is so rapid that females do not even feel when their young are born. The newborn moves from the vagina into the pouch and attaches itself to a teat. After birth, a young wallaby may spend up to 18 months inside the pouch. (Renfree and Tyndale-Biscoe, 1987)

The energy needed for daily activity remains low for many marsupial mothers during gestation. This indicates that the growing fetus requires little energetic investment from the mother. Investment in the young after birth is substantial, however. A female lactates for the entire time the young is in her pouch. Males do not stay around to look after the young, leaving the rearing of offspring to the mother. (Renfree and Tyndale-Biscoe, 1987)

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • extended period of juvenile learning

Lifespan/Longevity

There are no records of the lifespan of D. macleayi. However, a related species found in the same geographic range but at lower altitudes, Dorcopsulus luctuosa, has a maximum lifespan of eight years. Dorcopsulus macleayi probably has similar longevity. (Fisher, et al., 2001)

  • Average lifespan
    Status: captivity
    7.9 years
    AnAge

Behavior

Papuan forest wallabies are terrestrial herbivores/browsers. They forage on the soil surface for the most part and have limited ability to burrow. Their ability to survive on open habitat is reduced because they are forest specialists. They are presumed to be nocturnal. (Australian Marsupial and Monotreme Specialist Group, 2004; Lydekker, 1896)

Home Range

The size of home ranges in this species are not known. (Gilmore and Stonehouse, 1977)

Communication and Perception

Like most marsupials, Papuan forest wallabies have a well-developed sense of smell. Females release a strong scent when they are in estrus and ready to find a mate. In addition to using this olfactory cue of mating readiness, males also smell the genital area of a female to make sure that no young are already in the pouch.

In addition to olfactory communication, it is likely that in mating and during the pouch life of an offspring, much tactile information is exchanged. Visual cues may also be used in communication, but have not been documented. Similarly, the role of vocal communication has not been investigated. (Renfree and Tyndale-Biscoe, 1987)

Food Habits

Dorcopsulus macleayi is a generalist browsing herbivore. Its diet is composed of leaves, buds, and stems of dictotyledonous plants. (Cockburn and Lee, 1985; Lydekker, 1896)

  • Plant Foods
  • leaves
  • wood, bark, or stems

Predation

The major predators of this species are New Guinea harpy-eagles, carpet pythons, and wedge-tailed eagles. (Australian Marsupial and Monotreme Specialist Group, 2004; Dutson, 2004)

Ecosystem Roles

These wallabies are an important part of their ecosystem. They serve as prey for many animals, and have some affect on the vegetation they feed upon. (Tomasek, 2001)

Economic Importance for Humans: Positive

Several native tribes of the Papuan forest regions have used the furs of Papuan wallabies as a means of trade and as bridal gifts. Beyond this limited use, the species holds no real economic importance for humans. (Tomasek, 2001)

  • Positive Impacts
  • body parts are source of valuable material

Economic Importance for Humans: Negative

There is no known negative impact of this species on humans. (Dutson, 2004; Tomasek, 2001)

Conservation Status

Currently, D. macleayi is considered a vulnerable species that is subject to the effects of human activities. It has an unpredictable future. IUCN says that this species can very easily become critically endangered.

Several organizations are now working with farmers in New Guinea to protect and preserve the forests and the land, and are also helping preserve wildlife. They may be assisting the survival of this wallaby species.

In 1994, the World Wildlife organization began the Kikori Integrated Conservation and Development Project to promote wildlife management along with managed forestry and community development ideas. This project significantly helps conserve the endemic species of the forest.

Conservation Melanesia is another project works in Pacific Islands to protect the habitat for the species that dwell in the forest. (Australian Marsupial and Monotreme Specialist Group, 2004; Tomasek, 2001)

Contributors

Daniel Rosas Alvarez (author), University of Notre Dame, Karen Francl (editor, instructor), Radford University.

Nancy Shefferly (editor), Animal Diversity Web.

Glossary

acoustic

uses sound to communicate

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

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.

island endemic

animals that live only on an island or set of islands.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

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

oceanic islands

islands that are not part of continental shelf areas, they are not, and have never been, connected to a continental land mass, most typically these are volcanic islands.

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.

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

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.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

visual

uses sight to communicate

viviparous

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

References

Australian Marsupial and Monotreme Specialist Group, 2004. "Dorscopsulus macleayi" (On-line). Accessed April 09, 2006 at http://www.iucnredlist.org/.

Cockburn, A., A. Lee. 1985. Evolutionary Ecology of Marsupials. New York: Cambridge Press.

Dutson, G. 2004. "Papua New Guinea Tour Report" (On-line pdf). Accessed April 09, 2006 at http://birdquest.co.uk/reportfiles/papua%20new%20guinea%20rep%2004.pdf.

Fisher, D., I. Owens, C. Johnson. 2001. "The ecological basis of life history variation in marsupials" (On-line). Ecological Archives. Accessed April 09, 2006 at http://esapubs.org/archive/ecol/E082/042/appendix-A.htm.

Gilmore, D., B. Stonehouse. 1977. The Biology of Marsupials. London: University Park Press.

Lydekker, R. 1896. A Handbook to the Marsupalia and Monotremata. London: Edward Lloyd.

Nowak, R. 1999. Walker's Mammals of the World, Sixth Edition. Baltimore and London: The Johns Hopkins University Press.

Oldfield, T. 1888. Catalogue of the Marsupialia and Monotremata in the collection of the British Museum. London: Taylor and Francis.

Renfree, M., H. Tyndale-Biscoe. 1987. Reproductive Physiology of Marsupials. New York: Cambridge Press.

Tomasek, A. 2001. "About New Guinea" (On-line). WorldWildLife.org. Accessed April 10, 2006 at http://worldwildlife.org/expeditions/newguinea/about.cfm.