235.

Central Cordillera Brush Mouse

Coccymys shawmayeri

French: Coccymys de Shaw Mayer / German: Shaw-MayerBirstenschwanzmaus / Spanish: Raton de cepillo de Shaw Mayer

Other common names: Shaw Mayer's Coccymys, Shaw Mayer's Brush Mouse

Taxonomy. Rattus shawmayeri Hinton, 1943,

“Baiyanka, Purari-Ramu Divide, [Eastern Highlands Province], northeast [Papua] New Guinea, 8000 ft. [=2438 m].”

Coccymys shawmayeri was originally described as a highly distinctive species in genus Rattus, with possible links to Asian species now placed in genus Niviventer . Although this view was supported by various influential mammalogists, including J. R. Ellerman, the close relationship of shawmayeri to ruemmleri was apparently recognized in the 1980s by A. C. Ziegler and J. A. Mahoney, among others, but notformalized until 1993, when the two were synonymized by G. G. Musser and M. D. Carleton. More recently, Musser and D. P. Lunde recognized them as closely related, but taxonomically distinct, species. Monotypic.

Distribution. Central Cordillera of New Guinea, from the vicinity of Telefomin in West Sepik Province E to end of Owen Stanley Range.

Descriptive notes. Head-body 87-107 mm, tail 132-170 mm, ear 16-20 mm, hindfoot 24-27 mm; weight 22-7-45-4 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 prominent, forward-facing, and contained within 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, 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. The Central Cordillera Brush Mouseis distinguished within genus by shorter and paler, brownish-gray fur on upperparts; and tail usually longer (145-170% of head-body length) and usually (76%) with short white tip. Differences in cranial morphology also distinguish this species from congeners, including proportionally smaller molars and shorter rostrum. 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. Spermatozoa (described as C. ruemmleri) features falciform head with single apicalhook,tail moderately long.

Habitat. Recorded from lower and upper montane tropical forests, grading up into subalpine tussock grasslands and shrublands. At Apalu Reke at 2875 m in the Muller Range, Enga Province, the Central Cordillera Brush Mouse is abundant in clusters of low scrub ( Podocarpus, Podocarpaceae) within dominant Pandanws—Blechnum (Pandanaceae-Blechnaceae) community of the broad frost hollows, and less common in adjoining upper montane forest. Similar habitat around Lake Aunde at 3325 m on Mount Wilhelm, Western Highlands Province, produced captures in “long grass,” “peaty grassland” and “grass near subalpine forest.” In Upper Sol River valley an individual was taken from crown of a Pandanus palm at 2600 m. Known elevational range is from 1587 m (Sawetau, Muller Range) to 3660 m (Mount Wilhelm), but most records are from above 2500 m.

Food and Feeding. Analysis of stomach contents indicates strong focus on fruits, but seeds and insects are also ingested. Most insect remains are from beetles and cockroaches.

Breeding. Occupation of burrows is probably untenable in waterlogged ground of high-elevation tussock grasslands on Muller Range and Mount Wilhelm; in these localities the Central Cordillera Brush Mouse almost certainly nests off ground in dense shrubs or in crowns of Pandanus palms or tree ferns.

Activity patterns. The Central Cordillera Brush Mouse has not been observed to be active during day or evening, even where locally abundant, suggesting that it is probably strictly nocturnal. It has been trapped on ground and in low shrubs. Its body proportions are those of a skilled climber, and it almost certainly moves between ground and canopy in forest, or forages among shrubs in lower vegetation.

Movements, Home range and Social organization. No information.

Status and Conservation. Not assessed on The [UCN Red List but formerly included in Riitmmler’s Brush Mouse ( Coccymys ruemmleri), which was rated Least Concern. The high-elevation habitats occupied by the Central Cordillera Brush Mouse suffer little under traditional land-use patterns, but in some areas the species is under potential threat from regional resource-development activities.

Bibliography. Aplin & Kale (2011), Aplin, Singadan et al. (2016a), Breed & Aplin (1995), Ellerman (1949), Flannery (1995b), Flannery & Seri (1990), Helgen & Opiang (2011), Hinton (1943), Menzies (1990), Menzies & Dennis (1979), Misonne (1969), Musser & Carleton (1993, 2005), Musser & Lunde (2009), Tate (1951), Watts & Baverstock (1994a, 1996).