Phalanger orientalisgray cuscus

Ge­o­graphic Range

Pha­langer ori­en­talis is thought to have orig­i­nated on New Guinea and then to have been dis­trib­uted pri­mar­ily by pre­his­toric hu­mans to the range it cur­rently oc­cu­pies (Nowak, 1999). That range now in­cludes the South West Pa­cific is­lands of Buru, Seram, the Solomon and Molucca Is­lands, north­ern New Guinea, and the Bis­mark Arch­i­pel­ago (Nowak, 1999) . Until re­cently, P. ori­en­talis and P. in­ter­castel­lanus (South­ern Com­mon Cus­cus) were thought to be­long to the same species (Flan­nery, 1995). P. in­ter­castel­lanus in­hab­its north­ern Aus­tralia, the Aru Is­lands, and the Louisade Arch­i­pel­ago (Stra­han, 1995).

Habi­tat

P. ori­en­talis is re­sitricted to trop­i­cal rain­forests and thick scrub in the South West Pa­cific (Nowak, 1999). They have also been spot­ted in gar­dens, prob­a­bly due to the high abun­dance of ed­i­ble plants (Flan­nery, 1995).

  • Range elevation
    0 to 1600 m
    0.00 to 5249.34 ft

Phys­i­cal De­scrip­tion

P. ori­en­talis, like oth­ers in the fam­ily Pha­lan­geri­dae, is heavy and pow­er­fully built (Nowak, 1999). The av­er­age mass is about 2.1 kg. This is slightly lower in fe­males (Grizmek, 1990).

The tail is pre­hen­sile naked at the end. It is cov­ered with horny papil­lae. The tail length varies from 28 to 42 cm (Grizmek, 1990). The male tail is com­pletely white but fe­male tails are white only on the tips.

In adult males, the thick, wooly fur ranges in color from white to medium or dark grey (Nowak, 1999). In adult fe­males, the color ranges from red­dish-brown to brown­ish-grey. The stom­ach area is com­monly white. The male has a dis­tinct yel­low­ish chest gland. Usu­ally a dark stripe runs from the head to the lower back. The young of this species are red­dish-brown. (Flan­nery, 1995; Nowak, 1999)

The dig­its are of dif­fer­ent lengths and are tipped by long, curved claws. Their paws are syn­dacty­lous, with the first and sec­ond dig­its op­pos­able to the rest. The soles of their feet are naked and stri­ated. The fe­male pouch has four mam­mae (Nowak, 1999). The fa­cial fea­tures in­clude large eyes, long ca­nines and a snout longer than that of Spi­lo­cus­cus mac­u­la­tus (Spot­ted Cus­cus). The teeth are sim­ple, low crowned and used for grind­ing (Flan­nery, 1995).

  • Range mass
    1.0 to 5.0 kg
    2.20 to 11.01 lb
  • Average mass
    2.1 kg
    4.63 lb
  • Range length
    35 to 55 cm
    13.78 to 21.65 in
  • Average length
    39 cm
    15.35 in

Re­pro­duc­tion

The ges­ta­tion pe­riod for P. ori­en­talis lasts around 13 days. Nor­mally the fe­males births twins, but the num­ber of young ranges from one to three (Grizmek, 1990). Usu­ally, one of the twins dies be­fore wean­ing (Nowak, 1999). The weight at birth is less than 1 gram (Grizmek, 1990).

Nor­mally, the re­pro­duc­tive cycle oc­curs only once a year. Mat­ing and re­pro­duc­tive sea­sons are from June through Oc­to­ber, though March and No­vem­ber births have been ob­served (Tyn­dale-Brisco, 1987).

Be­cause P. ori­en­talis has not been well stud­ied, in­for­ma­tion on the re­proc­tive be­hav­ior is sparse.

  • Breeding season
    June through October
  • Range number of offspring
    1 to 3
  • Average number of offspring
    2
    AnAge
  • Average gestation period
    13 days
  • Range weaning age
    not known (high) days

Be­hav­ior

P. ori­en­talis is noc­tur­nal, spend­ing the day in a tree hol­low. While for­ag­ing for food at night, it trav­els through the for­est in a slow de­lib­er­ate climb (Nowak, 1999). P. ori­en­talis grips with three feet at a time and the tail wraps around the branch ready to hold weight. Ground travel -- though rare -- is char­ac­ter­ized by a slow, bound­ing gait. If nec­es­sary, P. ori­en­talis moves quickly through the canopy and even jump across gaps (Flan­nery, 1995).

P. ori­en­talis is soli­tary and has been ober­se­ved to be very in­tol­er­ant of Spi­lo­cus­cus mac­u­la­tus (Spot­ted Cus­cus) if they come in con­tact with one an­other. P. ori­en­talis is more tol­er­ant of hu­mans, and it is com­monly kept as a pet (Flan­nery, 1995).

Com­mu­ni­ca­tion and Per­cep­tion

Food Habits

P. ori­en­talis climbs slowly through the rain­forests and lo­cates mainly leaves, tree seeds, fruit, buds and flow­ers on which they feed (Girzmek, 1990). It has been spot­ted eat­ing the green fruit of the Red Cedar (Toona aus­tralis) and the buds and flow­ers of Corky Bark (Car­al­lia brachi­ata). A paste de­rived from the seeds of the Black Bean Tree (Cas­tanosper­mum aus­trale) was found in the stom­ach of one an­i­mal. While in cap­tiv­ity it pri­mar­ily eats leaves and fruit (Flan­nery, 1995).

Pre­da­tion

P. ori­en­talis had not been closely stud­ied due to its se­cluded lifestyle. The fol­low­ing are a few spe­cific preda­tors that have been doc­u­mented: White-bel­lied Sea-Ea­gle (Hali­aee­tus leuco­gaster) (Hein­sohn, 2000), Amethys­tine (More­lia ame­thistina)(Flan­nery, 1995), Car­pet Pythons (More­lia s. cheynei)(Flan­nery, 1995), and pos­si­bly Dasyurids (Grizmek, 1990). The as­sump­tion is that these and other species like them prey upon P. ori­en­talis.

Ecosys­tem Roles

P. ori­en­talis does not have any recorded eco­log­i­cal roles.

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

In New Guinea, P. ori­en­talis is hunted for food by na­tive tribes, though this is rare (Flan­nery, 1995).

  • Positive Impacts
  • food

Con­ser­va­tion Sta­tus

Con­trib­u­tors

Laura Merlo (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

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.

female parental care

parental care is carried out by females

folivore

an animal that mainly eats leaves.

food

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

frugivore

an animal that mainly eats fruit

herbivore

An animal that eats mainly plants or parts of plants.

introduced

referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.

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.

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.

seasonal breeding

breeding is confined to a particular season

sexual

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

solitary

lives alone

tactile

uses touch to communicate

tropical

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

viviparous

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

Ref­er­ences

1990. Grizmek's En­cy­clo­pe­dia of Mam­mals. Vol­ume 1. New York, NY: Mc­Graw-Hill Pub­lish­ing Com­pany.

Flan­nery, T. 1995. Mam­mal of the South-West Pa­cific and Moluc­can Is­lands. Chatswood, NSW: Reed Books as a part of Reed Books Aus­tralia.

Hein­sohn, T. Sep­tem­ber 2000. Pred­i­tion by the White-breasted Sea Eagle, Hali­aee­tus leuco­gaster, on pha­lan­gerid pos­sums in New Ire­land, Papua New Guinea. Emu - Aus­tral Orinthol­ogy, 100(3): 245-246.

Nowak, R. 1999. Walker's Mam­mals of the World, 6th edi­tion. Vol­ume 1. Bal­ti­more, MD: The Johns Hop­kins Uni­ver­sity Press.

Nowak, R. 1997. "Walker's Mam­mals of the World On­line 5.1" (On-line). Ac­cessed 7 Oc­to­ber 2001 at www.​press.​jhu.​edu/​books/​walkers_​mammals_​of_​the_​world/​marsupialia/​marsupialia.​phalangeridae.​phalanger.

Stone­house, B., D. Gilmore. 1977. The Bi­ol­ogy of Mar­su­pi­als. Bal­ti­more, Md: Uni­ver­sity Parks Press.

Stra­han, R. 1995. The Mam­mals of Aus­tralia. Chatswood, NSW: Reed Books for the Aus­tralian Mu­seum Trust.

Tyn­dale-Bis­coe, C., M. Ren­free. 1987. Re­pro­duc­tive Phys­i­ol­ogy of Mar­su­pi­als. New York, NY: Press Syn­di­cate of the Uni­ver­sity of Cam­bridge.