Niviventer rapit

6568.

Montane Bornean White-bellied Rat

Niviventer rapit

French: Rat rapit / German: Langschwanz-WeiRbauchratte / Spanish: Rata de vientre blanco de montana de Borneo

Other common names: Bornean White-bellied Rat, Long-tailed Mountain Rat, Montane Bornean Niviventer, Rapit Rat

Taxonomy. Mus rapit Bonhote, 1903,

“Mount Kina Balu, Borneo.”

Phylogenetic data have shown that N. rapt is sister to a group containing N. fulvescens and N. huang, although further genetic research is needed to validate this. Popu- lations from Sumatra are now allocated to N. fraternus and populations from Ma- lay Peninsula are included in N. cameron. Monotypic.

Distribution. Borneo.

Descriptive notes. Head—body 143 mm,tail 197 mm; weight 60 g(averages). The Montane Bornean White-bellied Rat is medium-sized, with spiny yet soft pelage. Dorsum is dark reddish brown, sides are lighter, and venter is white. Ears are dark brown; vibrissae are long. Tail is ¢.140% of head-body length, hairy, and either unicolored (dark brown) or bicolored (dark brown above, lighter below), and it ends in small tuft. Dark brown stripe goes down hands stopping before white feet. Skull is elongated and slender. There are five digits on each foot, with fifth digit reduced with small claw. The Montane Bornean White-bellied Ratis a host of the mesostigmatid mite genus Laelaps, including a new species, L. rapit. Tick genus Amblyomma has also been recorded on it. There are four pairs of mammae: one pectoral, one post-axillary, one abdominal, and one inguinal. Chromosomal complement is 2n = 46; FN = 60.

Habitat. Highland forests and scrublands at elevations of 600-3360 m.

Food and Feeding. No information.

Breeding. A female was seen moving her offspring (gripped in mouth by loose skin around neck) from a low groove in a bamboo shoot to a higher groove to avoid a copperhead rat snake (Coelognathus radiatus).

Activity patterns. The Montane Bornean White-bellied Rat is probably nocturnal and might be more arboreal than terrestrial.

Movements, Home range and Social organization. Apparently, Montane Bornean White-bellied Rats make nests in bamboo groves.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Montane Bornean White-bellied Rat apparently is relatively common in some regions but rare overall.

Bibliography. Adrus et al. (2011), Aplin (2016f), Bochkov et al. (2004), Lu Liang et al. (2015), Paramasvaran et al. (2009), Phillipps & Phillipps (2016), Musser (1981a), Musser & Carleton (2005).