713.

Richardson’s New Guinea Mountain Rat

Rattus richardsoni

French: Rat de Richardson / German: Richardson-Neuguinea-Ratte / Spanish: Rata de montana de Nueva Guinea de Richardson

Other common names: Glacier Rat, Richardson's Mountain Rat

Taxonomy. Rattus richardson: Tate, 1949,

“near Lake Habbema, north of Mt. Wilhelmina, Netherlands New Guinea, alti-tude 3225 meters.”

Rattus richardsoni has not been included in any phylogenetic study. It was previously considered a subspecies of R. omlichodes. Monotypic.

Distribution. W Central Cordillera of New Guinea, including Mt Jaya, around Lake Habbema, and Mt Trikora.

Descriptive notes. Head—body 122-133 mm,tail 128-142 mm, ear 22-7-24-7 mm, hindfoot 32-2-33-9 mm; weight 59-74 g. Richardson’s New Guinea Mountain Rat is small and distinctive, with very thick and very soft pelage compared with all other New Guinea murines, and it lacks spines. Dorsum is warm brown, with chestnut and rufous colors throughout; individual hairs are brown-tipped or chestnutto rufous-tipped, with dark steel dray base. Dorsal pelage blends to lighter rufous brown on sides and then into ventral pelage. Juveniles aredarker chocolate, with less developed rufous tipping. Venter is buffy white, exceptforsteel gray proximal part of underside. Feet are silvery white dorsally. Ears are pinkish gray, very long, and sparsely covered with dark fur; vibrissae are fairly long. Tail is ¢.105% of head-body length and rich brown dorsally and slightly lighter ventrally, with conspicuously long hairs throughout. Skull is elongated, with long rostrum. There are four pairs of mammae: one pectoral, one post-axillary, and two inguinal.

Habitat. Tussock grassland and bare tundra-like habitat of largely rock or gravel with widely interspersed mats of herbs and grass tufts and areas uncovered by glacial retreat at elevations of 3225-4500 m. In New Guinea, Richardson’s New Guinea Mountain Rat is found in the last areas that have glaciers, and the region is wet and cold year-round.

Food and Feeding. No information.

Breeding. Young Richardson’s New Guinea Mountain Rats were recorded in May-June; subadults were collected in May.

Activity patterns. No information.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Vulnerable on The IUCN Red List. Richardson’s New Guinea Mountain Rat occurs in less than 20,000 km?, with few known localities, and extent and quality of its habitat continue to decline primarily due to increased fire frequency. It is also confined to habitats reliant on remnant glaciers that are continually decreasing in size.

Bibliography. Flannery (1995b), Leary & Wright (2016b), Musser & Carleton (2005), Taylor, Calaby & Smith (1990), Taylor, Calaby & Van Deusen (1982).