795.

Komodo Rat

Komodomys rintjanus

French: Rat de Komodo / German: Komodo-Ratte / Spanish: Rata de Komodo

Other common names: Nusa Tenggara Komodomys

Taxonomy. Rattus rintjanus Sody, 1941,

Lohoboeaja, Pulau Rintja, Nusa Tenggara,

Indonesia.

This species is monotypic.

Distribution. Known only from Rinca and Padar Is, Tenggara Is, Indonesia; it probably also occurs on other islands in the Lesser Sunda chain (e.g. Komodo).

Descriptive notes. Head-body 120- 180 mm, tail 120-163 mm, ear 19-22 mm, hindfoot 29-36 mm; weight 59-155 g. The Komodo Rat is a amedium sized rat with thick, coarse, and spinous fur. Dorsal pelage is straw-yellow or buff flecked with brown. Middle of head and body, from nose to rump, is darker, suffused with more brown. Cheeks and sides of head and body are paler, suffused with gray. Many guard hairs emerge from the coat and are longest near the rump, reaching 40-50 mm. Guard hairs, along with fine underfur, coarse overhairs, and flexible flattened spines, form the dorsal coat. Underhairs and overhairs are gray for most of their lengths, then banded with pale brown and tipped with buff or straw-yellow, a pattern also found on the guard hairs. Spines are translucent and tipped with pale buff or straw-yellow. The dark vibrissae extend up to 55 mm. There is a conspicuous triangle of bright buffy hairs behind each eye. Ears are tan and covered with fine, short hairs. Ventral pelage is composed of fine underhairs, short overhairs, and scattered soft spines and is shorter and much softer than the dorsal coat. Hairs have pale gray or dark gray bases and white tips, the thin soft spines are white. Overall color of ventral coat is white, moderately or densely suffused withpale or dark gray. Some specimens have whitish-gray underparts tinged with buff. Hindfeet are long and narrow. Digits are long, as are nails, which are nearly straight on the hindfeet. Dorsal surfaces of all four feet are densely covered by white hairs. Claws are cream in color and overladen with long white hairs. Palmar and plantar surfaces are naked, tan, and have small oblong pads. There are five pads on each palmar surface (three interdigital and two palmar) and six pads on each ofthe plantar surfaces (four interdigital and two plantar). Tail is short (c.90-100% of head-body length), coarselyscaled, and covered with long silver hairs. Dorsal surface and sides of tails are dark brown, ventral surface is paler, ranging from whitish-brown to tan and the proximal third is nearly unpigmented in some specimens. Pelage ofjuveniles is colored much like the fur of adults, but is shorter and softer, with a finer, silky texture. Skull is strongly curved dorsally between tip of nasal toward occiput. Rostrum is long and narrow. Interorbital area is flat and wide, and there are weak ridges on dorso-lateral margin of braincase. Females have five pairs of mammae: two post-axillary, one abdominal, and two inguinal pairs. Lacrimal is large, and zygomatic plate is wide, angular, and squarish. Braincase is wide and deep; interparietal is reduced; long and narrow incisive foramina widen posteriorly; incisive foramina reach level of M'; palatal bridge is short; and mesopterygoid fossa is narrow, with deep ectopterygoid fossae and some expansive sphenopalatine vacuities. Tympanic bullae are large and deep. Heavy teeth are very characteristic, with high conic cusps; cusps on M' and M? slant posteriorly, resulting in great overlap between M' and M” and between M? and M®. M' is anchored by five roots. Laminae on M' and M? formed high, separate cone-like cylindrical cusps; second row of labial cusp in M' is well-separated from medial one; cusp t7 and posterior cingulum are absent on upper cheek teeth; M?is wider than M' and M?; and jaw is long and lowjaw, with weak coronoid process.

Habitat. Rocky habitats, tall thickets, near gallery forests close to streams, and mainly dry thornscrub habitats.

Food and Feeding. The Komodo Ratis probably herbivorous.

Breeding. No information.

Activity patterns. The Komodo Rat is nocturnal.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Vulnerable on The IUCN Red List. The Komodo Rat seems to be abundant based on the number of specimens collected for the type series. It may be found on the nearby Flores Island and Komodo Island, although surveys are needed to confirm this. The species seems to be resilient and adaptable since the islands in which it is found have been highly degraded. Further research is needed to fully understand the evolution, ecology, and potential threats to this species.

Bibliography. Musser & Boeadi (1980), Sody (1941).