234.

Rimmler’s Brush Mouse

Coccymys ruemmleri

French: Coccymys de Riimmler / German: Rimmler-Birstenschwanzmaus / Spanish: Raton de cepillo de Rimmler

Other common names: Rimmler's Coccymys, Rummler’'s Mouse

Taxonomy. Pogonomelomys ruemmler i Tate & Archbold, 1941,

“Lake Habbema, north slope of Mt. Wilhelmina, [Snow Mountains, Papua Province,] Netherlands New Guinea, altitude 3225 meters.”

Originally described as a species of Pogonomelomys, but later placed in its own genus. C. ruemmleri formerly included C. shawmayeri as a synonym, but G. G. Musser and D. P. Lunde in 2009 demonstrated three species in the genus, with ruemmleri restricted to western part of the wider distribution. Monotypic.

Distribution. Snow and Star Mts, Central Cordillera of New Guinea.

Descriptive notes. Head-body 93-114 mm, tail 122-171 mm, ear 15-21 mm, hindfoot 25-28 mm; weight 34 g. Coccymys are small murines with soft, dense fur, reddish brown to dark brown over dark gray on upperparts, and gray washed with cream or buff below; head broad, with short snout bearing very long vibrissae that extend past ears when folded back; eyes are prominent, forward-facing, and contained within a dark mask that extends forward onto muzzle; ears are small, dark brown, and covered in fine hairs; feet unpigmented and covered in white or clear hairs, moderately long, slender hindfeet with claws on all digits and large plantar pads. Tail is much longer than head-body length, finely scaled and thinly furred with three hairs per scale, no terminal tuft, upper surface with smooth “prehensile” pad, dark for entire length or with short white tip. Cranium is characterized by relatively robust incisors with orange enamel, small molars with simple cusp patterns, moderately large auditory bullae. Rimmler’s Brush Mouse is distinguished by dark brown to very dark brown fur on upperparts, whitish-gray wash on underparts; long tail (140-146% of head-body length) usually dark to tip, less often (11%) with short white tip. Differences in cranial morphology also distinguish this species from congeners. Juveniles have shorter pelage, but coloration and patterning otherwise similar to those of adults. Mammae three on each side, one post-axillary and two inguinal.

Habitat. All records are from upper montane tropical forest, grading up into ecotones with subalpine tussock grassland and shrubland. The lower elevations in Snow Mountains area in late 1930s were a mosaic of primary and secondary forests and active subsistence gardens; most specimens were collected by local people who ranged up to local ridgetops at 3000 m. There are no confirmed records of Rimmler’s Brush Mouse in secondary forest or anthropogenic habitats. In Star Mountains,it was snap-trapped in “grass” and “moss forest + grass” at 3100 m, but also in “moss forest” at 3100 m and 3200 m. Elevational range is thus between 2200 m and tree-line at 4050 m in Snow Mountains, and 3100-3200 m in Star Mountains.

Food and Feeding. Presumably fruits and also commonly seeds and insects.

Breeding. No information.

Activity patterns. Riimmler’s Brush Mouse has been trapped on ground, but its body proportions indicate that it is almost certainly a scansorial species, moving between ground and canopy, or foraging among shrubs in lower vegetation.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red List, but not reassessed since the taxonomic separation of Rliimmler’s Brush Mouse and the Central Cordillera Brush Mouse ( C. shawmayeri). The high-elevation habitats occupied by Rimmler’s Brush Mouse suffer little under traditional land use, but they face potential impact from regional resource-development activities.

Bibliography. Aplin, Singadan etal. (2016a), Flannery (1995b, 1999), Hope (1976), Menzies (1990), Menzies & Dennis (1979), Musser & Carleton (1993, 2005), Musser & Lunde (2009).