710.

Arianus’s New Guinea Mountain Rat

Rattus omichlodes

French: Rat des brumes / German: Misonne-Neuguinea-Ratte / Spanish: Rata de montana de Nueva Guinea de Aranius

Other common names: Arianus'’s Rat

Taxonomy. Rattus omichlodes Misonne, 1970,

Ertsberg (4°04 8S, 137°07 bE), 3400 m, western Snow Mountains (= Pegunungan Maoke), Province of Papua, West Papua (= Irian Jaya), New Guinea.

Rattus omichlodes has not been included in m)’ genetic studies and was included in R. nichardsoni. Monotypic.

Distribution. W Snow Mts, W New Guinea.

Descriptive notes. Head—body 128-139 mm, tail 95-8-101 mm, ear 19-20-7 mm, hindfoot

28-2-28-8 mm; weight 69-78 g. Arianus’s New Guinea Mountain Rat is small, distinctive, and similar to Richardson’s New Guinea Mountain Rat ( R. richardsoni), buttail is shorter and feet are completely black. Pelage is long, dense, and soft. Dorsum is somewhat ginger furred, with light gray hairs and brown tips (being browner on sides than on Richardson’s New Guinea Mountain Rat). Dorsal pelage blends into ventral pelage. Venter is lighter brown than dorsum, with gray base. Feet are distinctly dark grayish black. Ears are broad and fringed with gingerfur; vibrissae are relatively short. Tail is ¢.75% of head-body length. Skull is smaller than in Richardson’s New Guinea Mountain Rat and without beaded interorbital constrictions. There are three pairs of mammae: one pectoral and two inguinal.

Habitat. Alpine scrub, shallow marshes, and boggy alpine heath at elevations of¢.2950 m.

Food and Feeding. No information.

Breeding. No information.

Activity patterns. No information.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Data Deficient on The IUCN Red List. Arianus’s New Guinea Mountain Rat has a very restricted distribution, but it occurs in Lorentz National Park. More research is needed to fully understand its natural history and conservation threats.

Bibliography. Flannery (1995b), Leary, Singadan, Menzies, Wright, Lunde & Aplin (2008), Misonne (1979), Musser & Carleton (2005), Taylor, Calaby & Smith (1990), Taylor, Calaby & Van Deusen (1982).