184.

Koopman'’s Pencil-tailed Tree Mouse

Charopodomys karlkoopmani

French: Souris-a-pinceau de Koopman / German: Koopman-Pinselschwanz-Baummaus / Spanish: Raton arboricola de cola de lapiz de Koopman

Taxonomy. Chiropodomys karlkoopmani Musser, 1979,

“North Pagai Island (Pulau Pagai Utara), part of the Mentawai Islands off the coast of southwestern Sumatra,” Indonesia.

Chiropodomys karlkoopmani is monotypic.

Distribution. Known only from Siberut and North Pagai Is (Mentawai Is).

Descriptive notes. Head-body 107 mm, tail 171 mm, ear 17 mm, hindfoot 29 mm. No specific data are available for body weight.

Koopman’s Pencil-tailed Tree Mouse is the largest species of Chiropodomys, with typical body form for this arboreal genus—short headwith large eyes, moderately large, thinly furred ears, and elongate, narrow vibrissae that, folded back, extend up to halfway along length of body; slender body clothed in short, soft, dense fur with inconspicuous scattered guard hairs; short broad hindfoot with nailed hallux and short, recurved claws on second to fourth digits; elongate, wellfurred tail that bears distinct brush or terminal tuft; and two mammae on each side, both inguinal. Coloration is subdued, fur dark grayish brown on dorsum, grayer on flanks, and pale gray on venter. Fur on chin and throat is white, gray on cheeks; dark brown fur on tip of nose and encircling eyes. Foreand hindfeet are proportionally larger than in other Chiropodomys species and clothed with dark brown hairs that extend on to digits. Tail is proportionally longer and with longer hairs than in other members of genus; hairs are brown for basal third and white for brush-like distal two-thirds. Skull is distinguishable from that of other members of genus by combination oflarge size, moderately reduced molars, and relatively small auditory bullae. Juvenile has shorter and finer pelage, dorsum dark gray and venter white or cream,tail dark or mottled as in adults.

Habitat. Tropical primary lowland forests.

Food and Feeding. No information.

Breeding. No information.

Activity patterns. Koopman'’s Pencil-tailed Tree Mice are arboreal and probably active mainly at night.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Vulnerable on The IUCN Red List owing to a rather small extent of occurrence (c.11,000 km?) and a continuous decline in the extent and quality of its forest habitat. Koopmans Pencil-tailed Tree Mouse is known only from only two locations.

Bibliography. Clayton & Kennerley (2016d), Jenkins & Hill (1982), Musser (1979).