229.

White-toothed Mouse

Brassomys albidens

French: Rat a dents blanches / German: Neuguinea-Weifzahnmaus / Spanish: Raton de dientes blancos

Other common names: \White-toothed Brush Mouse, White-toothed Coccymys, White-toothed Melomys

Taxonomy. Melomys albidens Tate, 1951,

“Lake Habbema, 15 miles [= 24 km] north of Mt. Wilhelmina [Snow Mountains], Netherlands New Guinea, altitude 3225 meters.”

Brassomys albidens was originally described within genus Melomys, later affiliated with ‘Pogonomelomys’ ruemmler: and in 1993 placed with that species in genus Coccymys by G. G.Musser and M. D. Carleton. In 2009,it was awarded its own, monotypic genus by Musser and D. P. Lunde. Monotypic.

Distribution. Known only from Bele River valley, vicinity of Lake Habbema, WC New Guinea; it may occur on Mt Minni, Star Mts, but capture of a living animal is needed to confirm species identity.

Descriptive notes. Head—body 111-122 mm, tail 144-162 mm, ear 18-22 mm, hindfoot 25-27 mm. No specific data are available for body weight. All adult specimens are male. The White-toothed Mouse is a small murine with soft, thick and woolly fur, dark brown on upperparts and whitish gray to ocherous on underparts. Snout is moderately long, vibrissae very long, dark mask surrounding unreduced eye, ears large, dark brown and thinly furred; foreand hindfeet have dark hairs on upper surfaces; hindfeet are narrow, with small plantar pads and claws on all digits. Tail is slender and elongate, 121-146% of head-body length, usually dark to tip but occasionally with short white tip, finely scaled and with three elongate hairs per scale, visibly hairy but lacking terminal brush or prehensile terminal pad. Dentition is characterized by incisors with white or cream enamel, molars with cusps united into simple transverse laminae. Mammae not illustrated on available specimens.

Habitat. Habitat surrounding Lake Habbema and downslope in upper Bele River valley is mossy, upper montane forest dominated by Antarctic beech ( Nothofagus, Nothofagaceae) that forms a narrow ecotone at ¢.3100 m with subalpine coniferous forests and shrublands.

Food and Feeding. Morphology of skull and teeth suggest a dietary focus on invertebrates, probably including insects and earthworms.

Breeding. No information.

Activity patterns. The somber coloration of the White-toothed Mouse suggests a nocturnal lifestyle.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Data Deficient on The IUCN Red List (as Coccymys albidens). The high-elevation habitats occupied by the White-toothed Mouse suffer little impact under traditional land-use patterns, but they are under potential impact from regional resource-development activities.

Bibliography. Archbold et al. (1942), Flannery (1995b, 1999), Helgen & Wright (2017), Menzies (1990, 1996), Musser & Carleton (1993, 2005), Musser & Lunde (2009), Tate (1951).