677.

Kinabalu Rat

Rattus baluensis

French: Rat du Kinabalu / German: Kinabalu-Ratte / Spanish: Rata de Kinabalu

Other common names: Summit Rat

Taxonomy. Mus baluensis Thomas, 1894,

“Mount Kina Balu, 8000 feet [= 2438 m].”

Rattus baluensis is in the R. rattus species group; it is most closely related to R. tiomanicus and has included R. korinchi as a subspecies. It may actually be the same species as R.tiomanicus based on a recent study that had a specimen of R. baluensisthat clustered with R. tiomanicus . Monotypic.

Distribution. Mt Kinabalu, N Borneo.

Descriptive notes. Head-body 158- 188 mm, tail 175-205 mm, hindfoot 30-35 mm; weight 108 g. The Kinabalu Rat is a medium-sized, with long, dense, and soft pelage. Dorsum is dark tawny, with long black guard hairs mixed throughout, and slightly lighter on sides. Hairs are gray-tipped with ocherous tawny bases. Venteris buffy gray in contrast to grayish white on the Sumatran Mountain Rat ( R. korinchi), and it is not sharply demarcated from dorsum. Feet are brown, with darker brown stripe down each metatarsal and metacarpal; claws are sharp, recurved, and short. Ears are small, brown, and covered with short brown hair. Tail is ¢.110% of head— body length and unicolored brown, covered in dark brown hair. Skull has slightly more inflated nasolacrimal capsules than on the Sumatran Mountain Rat. There are five pairs of mammae: one pectoral, one post-axillary, two abdominal, and one inguinal.

Habitat. Montane and moss forests and subsummit dwarf forest and scrub at elevations of 1524-3810 m.

Food and Feeding. The Kinabalu Rat has been recorded licking inner surfaces of pitcher plants ( Nepenthes rajah, Nepenthaceae) while defecating in them, indicating mutualistic symbiosis because pitcher plants feed on fecal matter.

Breeding. No information.

Activity patterns. The Kinabalu Rat is probably mostly terrestrial and nocturnal.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Kinabalu Rat has a restricted distribution, butit is found in Mount Kinabalu National Park and is relatively common. There are no major threats currently known, and it is considered fairly adaptable.

Bibliography. Aplin (2016c), Aplin et al. (2011), Greenwood et al. (2011), Musser (1986), Musser & Carleton (2005), Musser & Newcomb (1983), Nor (2001), Phillipps & Phillipps (2016), Wells et al. (2011).