21.

Stein’s Cuscus

Phalanger vestitus

French: Phalanger de Stein / German: Steins Kuskus / Spanish: Cuscus de Stein

Taxonomy. Cuscus vestitus Milne-Edwards, 1877,

“les monts Karons” (= Karons Moun- tains, Tamrau Range, Vogelkop Peninsula, West Papua, Indonesia).

The widely separated subpopulations of P vestitus are distinctive, and their taxonomy needs to be reevaluated; it is likely more than one species is involved. Three subspecies recognized.

Subspecies and Distribution.

P.v.vestitusMilne-Edwards,1877—Bird'sHead(=Vogelkop)Peninsula(ArfakandTamrauMts,1200-2200m).

P.v.interpositusStein,1933—WeylandMtsofWCentralRange,perhapsalsoincludingStar(=Jayawijaya)MtspopulationsinthemiddleoftheCentralRange,1400-2000m.

P. v. permixtio Menzies & Pernetta, 1986 — E Central Range in Papua New Guinea, 1000-1600 m.

Descriptive notes. Head—body 3548-5 cm, tail 29-36 cm; weight 1.4-2.4 kg. Stein’s Cuscus is a medium-sized cuscus (condylobasal length 72-82 mm), broadly equivalent in size to the two other widespread montane endemic cuscuses in New Guinea, the Mountain Cuscus (P. carmelitae) and the Silky Cuscus (P. sericeus). Color of Stein’s Cuscus is variable across its distribution. In central and western parts of its distribution,it has a distinct white elbow patch, not seen in any other species of phalangerid. Stein’s

Cuscus differs from the Mountain Cuscus and the Silky Cuscus in having gray or silvery rather than blackish fur and relatively broad dark dorsal stripe. It also differs from the Northern Common Cuscus (P. orientalis) in having a broaderstripe and longerfur. Tail of Stein’s Cuscus is naked and little tuberculated (except in males) at the base relative to all other species of phalangerids, except the Silky Cuscus.

Habitat. Lower and mid-montane primary forests. In areas where Stein’s Cuscus has been best studied,it inhabits primary oak forest and appears to tolerate only a limited amount of disturbance. Stein’s Cuscus can be found in the same forests with congeners including the Silky Cuscus, Mountain Cuscus, Ground Cuscus (P. gymnotis), and the Telefomin Cuscus (P. matanim).

Food and Feeding. Like other species of phalangerids, Stein’s Cuscus is primarily folivorous—frugivorous. Based on studies of stomach contents, it also consumes flowers, flower buds, and pollen. Other observations have found them to eat acorns from Lithocarpus and Castanopsis (both Fagaceae). One observation of cecotrophy was recorded in a captive individual.

Breeding. There is no specific information available for this species, but Stein’s Cuscus produces one offspring at a time.

Activity patterns. Stein’s Cuscus is nocturnal and typically solitary. Sleeping sites include tree hollows and bases of hollow tree trunks.

Movements, Home range and Social organization. There is no information available for this species.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Principal conservation threats to Stein’s Cuscus include extensive clearing of habitat and widespread hunting. Areas where it primarily occurs are in the elevational range most favored for traditional gardens, so it is likely that its habitat is disturbed throughout most ofits potential distribution.

Bibliography. Flannery (1994a, 1995a), George (1987), Leary, Singadan, Menzies, Helgen, Wright, Allison, Aplin, Salas & Dickman (2008), Menzies & Pernetta (1986).