Class Mammalia Order Diprotodontia Suborder Phalangerida Family Phalangeridae

Thumbnail description

Small- to medium-sized marsupials with clawed, grasping hands and feet with five digits, a long, prehensile tail with a naked underside, and a slightly elongate muzzle


Total length 23.6-47.2 in (60-120 cm); weight 2-22 lb (1-10 kg)

Number of genera, species

6 genera; 26 species


Forest and woodlands Conservation status

Endangered: 2 species; Vulnerable: 2 species; Lower Risk/Near Threatened: 1 species; Data Deficient: 5 species


Australasia east of Wallace's Line, including Sulawesi, Timor, the Moluccas, New Guinea, and many closely adjacent islands, as well as Australia and Tasmania; introduced to New Zealand


Australasia east of Wallace's Line, including Sulawesi, Timor, the Moluccas, New Guinea, and many closely adjacent islands, as well as Australia and Tasmania; introduced to New Zealand

Evolution and systematics

The phalangers (family Phalangeridae) are classified into six distinctive genera. The most diverse genus, Phalanger, comprises a group of medium-sized, soft-furred species that generally possess a dorsal stripe. Phalanger is primarily a New Guinean genus, but one species extends to northern Australia and several others occur throughout the Moluccan islands of Indonesia. Spotted cuscuses (genus Spilocuscus) are the most beautiful of the phalangers, with striking coats colored with combinations of red, white, black, brown, and yellow; they occur throughout New Guinea and on several adjacent islands, as well as in far northeastern Australia. The small-bodied species of Strigocuscus and the very large bear cuscuses (Ailurops) both occur only on Sulawesi and closely adjacent islands. Species of Phalanger, Spilocuscus, Strigocuscus, and Ailurops are all called cuscuses, whereas the remaining two genera within the family, Tri-chosurus and Wyulda, are called possums. Both of these latter genera are endemic to Australia. The five species of brush-tailed possums (Trichosurus) are (or were, until quite recently) distributed across most the Australian continent, while the rare scaly-tailed possum (Wyulda squamicaudata) occurs only in a small area of far northwestern Australia and is classified in a genus unique to itself. The phalanger fossil record extends back roughly 20 million years, to the middle Miocene, when three phalangerid genera (Trichosurus, Wyulda, and possibly Strigocuscus) occurred in northern Australia. The fossil history of pha-langerids outside of mainland Australia is very poorly known. Within the family, species of Trichosurus and Wyulda are clearly closely related to one another, as are those of Phalanger and Spilocuscus. However, the exact relationships of these two groups with one another and with Strigocuscus and Ailurops remain obscure. The phylogenetic position of the genus, Ailurops, is particularly controversial. Anatomical evidence strongly suggests that the bear cuscuses are the most primitive phalangers—the first offshoot on the phalanger family tree. However, evidence from molecular studies does not support this hypothesis thus far. Future studies based on analysis of DNA will hopefully offer greater resolution of relationships within the family.

Physical characteristics

Phalangers are small- to medium-sized marsupials. The smallest phalanger (Strigocuscus celebensis) weighs 2 lb (1 kg)

A Sulawesi bear cuscus (Ailurops ursinus) feeds in guava tree in northern Sulawesi, Indonesia. (Photo by Janis Burger. Bruce Coleman, Inc. Reproduced by permission.)

or less, and the largest species (Ailurops ursinus) weighs up to 22 lb (10 kg); but most species of the family weigh between 3 and 6 lb (1.5-3 kg). The pelage is generally soft and dense. Color varies widely, especially in the spotted cuscuses and the beautifully mottled Woodlark cuscus (Phalanger lullulae), but most species are brown or gray, often with a dark dorsal stripe running down the center of the head and back. In all species except those of the genus, Tri-chosurus (which has a superficially dog- or fox-like appearance), the ears are reduced and often wholly or partially hidden in the soft fur. The feet have five digits, all of which support a large claw, except the hallux (big toe). The hal-lux is opposable to the remaining digits of the hind foot, and the first two digits of the forefoot oppose the remaining three, allowing the feet to grasp branches firmly while climbing. The second and third digits of the hindfoot are reduced and partially united by skin to form a single functional digit with two claws (a condition called syndactyly) that is used as a hair comb. The tail is long and prehensile, with the distal part generally naked (only on the underside in the bushy-tailed species of Trichosurus) and (especially in

A brushtail possum (Trichosurus vulpecula) mother and baby in Queensland, Australia. (Photo by Jen and Des Bartlett. Bruce Coleman, Inc. Reproduced by permission.)
A young brushtail possum (Trichosurus vulpecula) enters its mother's pouch. (Photo by Joyce Photographics/Photo Researchers, Inc. Reproduced by permission.)
A mountain brushtail possum (Trichosurus caninus) foraging in Queensland, Australia. (Photo by Jan Taylor. Bruce Coleman, Inc. Reproduced by permission.)

An adult spotted cuscus (Phalanger maculatus) nibbling leaves at night. Cuscuses are hunted for food and skins. (Photo by Zoltan Takacs. Bruce Coleman, Inc. Reproduced by permission.)

An adult spotted cuscus (Phalanger maculatus) nibbling leaves at night. Cuscuses are hunted for food and skins. (Photo by Zoltan Takacs. Bruce Coleman, Inc. Reproduced by permission.)

older males) covered with small tubercles that give it a strongly rugose surface.


Phalangers occur naturally throughout New Guinea, Australia, and Tasmania, and on a number of Indonesian islands (Sulawesi and the Moluccas). Cuscuses were prehistorically introduced from New Guinea to many nearby islands (including Timor and the Bismarck and Solomon Archipelagos), and the common brush-tailed possum was introduced to New Zealand from Tasmania and mainland Australia in the mid-nineteenth century.


All phalangers are well adapted for climbing and are highly reliant on trees, which they use for shelter, foraging, or both. Most species are inhabitants of rainforest, although the scaly-tailed possum occurs in rocky areas in broken sandstone coun-

A possum mother carries her young on her back. (Illustration by Jar-rod Erdody)
A ground cuscus (Phalangergymnotis) eating seeds in the Aru Islands near New Guinea. (Photo by Rod Williams. Bruce Coleman, Inc. Reproduced by permission.)

sis, and the mountain brush-tailed possum, Trichosurus cani-nus), but the majority of species are solitary. Males of most species are aggressive toward one another and cannot be kept together in captivity.

Feeding ecology and diet

Though phalangers are almost exclusively herbivorous, the kinds of plants favored can vary greatly from species to species. Some phalangers, including the Sulawesi bear cus-cus (Ailurops ursinus), are largely folivorous, while others such as the ground cuscus and the small Sulawesi cuscus are primarily frugivorous. Both leaves and fruit probably form high proportions of the diet of most species, especially in tropical forests; other food sources such as flowers, bark, pollen, and fungi may also be utilized in small quantities. The common brush-tailed possum is the most ecologically versatile phalanger and probably has the most generalized diet; its diet may change drastically in different local habitats, variably comprising large proportions of leaves (including some defended by highly toxic compounds), grasses and herbs, ferns and mosses, and fruits.

Reproductive biology

Although many species are monogamous, most are probably promiscuous. Female phalangers have a forward-oriented pouch with two or four teats. Adult females generally produce one or two litters per year. Up to three or four young may be born, but only one is usually reared, although in the northern common cuscus (Phalanger orientalis), twins are commonly raised. Gestation is 20 days or less; like other marsupials, neonates are born very small and unfurred. Infants are weaned and exit the pouch between five and eight months, after which they are carried on their mother's back.

try in northwestern Australia, and the remarkably versatile common brushtail possum (Trichosurus vulpecula) occupies a varied range of habitats and is common even in urban areas. Phalangers reach their greatest diversity in mid-montane rainforest in central New Guinea, where up to five species of the family coexist.


Most phalangers are nocturnal, but the two largest species (the Sulawesi bear cuscus, Ailurops ursinus, and the blackspotted cuscus, Spilocuscus rufoniger) are often active by day. Most species are arboreal, living in tree hollows and feeding in the forest canopy. However, one species, the ground cus-cus (Phalanger gymnotis) of New Guinea, exhibits a more terrestrial lifestyle; it lives in underground burrows and travels along the rainforest floor. However, even the ground cuscus is a very good climber, ascending into trees to feed on fruit at night. The social behavior of most phalangers has received little study to date. Several species seem to form male-female pairs (such as the small Sulawesi cuscus, Strigocuscus celeben-

Conservation status

Several phalanger species are in danger of extinction. Four rare species with small geographic ranges are particularly threatened: the scaly-tailed possum of northwestern Australia, the Telefomin cuscus (Phalanger matanim) of central New Guinea, the black-spotted cuscus of northern New Guinea, and the yellow bear cuscus (Ailurops melanotis) of the Sangihe and Talaud Islands in eastern Indonesia. Other species that are locally common but restricted to single islands, such as the Waigeo cuscus (Spilocuscus papuensis), the Gebe cuscus (Phalanger alexandrae), and the Woodlark cus-cus, are also worthy of conservation attention. However, many other phalangers, including the northern common cus-cus (Phalanger orientalis) and the common brushtail possum, are both geographically widespread and locally common and are presently under no threat.

Significance to humans

Cuscuses are an important source of meat for people throughout the New Guinea region, and they are widely hunted. However, in some areas of Indonesia such as the Sula Islands in the western Moluccas, cuscuses are not eaten in accordance with religious traditions. Common brushtail pos sums have unfortunately become a significant environmental and agricultural pest in New Zealand, where they have been introduced and are now widespread and common.

1. Sulawesi bear cuscus (Ailurops ursinus); 2. Common spotted cuscus (Spilocuscus maculatus); 3. Scaly-tailed possum (Wyulda squamicau-data); 4. Black-spotted cuscus (Spilocuscus rufoniger); 5. Small Sulawesi cuscus (Strigocuscus celebensis); 6. Common brushtail possum (Tri-chosurus vulpecula); 7. Ground cuscus (Phalanger gymnotis). (Illustration by Bruce Worden)

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