703.

Western New Guinea Mountain Rat

Rattus arrogans

French: Rat des Snow / German: Kleine Westneuguinea-Ratte / Spanish: Rata de montana de Nueva Guinea occidental

Taxonomy. Stenomys arrogans Thomas, 1922,

“Doormanpad-bivak, 2400 m,”

northern slopes Snow Mountains (Pegunungan Maoke), Province of Papua, New Guinea.

Rattus arrogans has not been included in

any phylogenetic studies, and additional research is needed to understand its placement in Rattus . It was previously included in R. niobe but is recognized as a species until further research into the R. niobe species complex is conducted. Monotypic.

Distribution. W New Guinea.

Descriptive notes. Head-body 130-6 mm, tail 113-6 mm, ear 17 mm, hindfoot 27-6 mm (averages). No specific data are available for body weight. The Western New Guinea Mountain Rat is very small and similar to but on average larger than the Eastern New Guinea Mountain Rat ( R. niobe). Pelage is soft and without spines. Dorsum is dark graybrown, nearly black, and with rusty tipped hairs (darker than those on the Eastern New Guinea Mountain Rat). Dorsal pelage blends into ventral pelage. Venter is dark graybrown, with cream to rufous-tipped hairs. Feet are lightly covered in silvery and brown hairs dorsally. Ears are dark brown and relatively long; vibrissae are long. Tail is ¢.87% of head-body length and unicolored dark brown, with shorttail hair. Skull has broader interorbital region and long incisive foramen. There are three pairs of mammae: one pectoral and two inguinal pairs.

Habitat. Montane moss forest and alpine habitats at elevations of 2200-4100 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 Least Concern on The IUCN Red List. The Western New Guinea Mountain Rat has a large distribution and presumably large overall population and is found in multiple protected areas. Additional research is needed to fully understand its natural history and conservation threats.

Bibliography. Aplin (2016h), Flannery (1995b), Helgen (2007a), Laurie & Hill (1954), Musser & Carleton (2005), Taylor, Calaby & Smith (1990), Taylor, Calaby & Van Deusen (1982).