656.

Montane Sumatran White-bellied Rat

Niviventer fraternus

French: Rat jumeau / German: Sumatra-WeilRbauchratte / Spanish: Rata de vientre blanco de montana de Sumatra

Other common names: Montane Sumatran

Niviventer

Taxonomy. Epimys fraternus H. C. Robinson & Kloss, 1916,

“Sungei Kumbang, Ko-rinchi, 4,700’ [= 1432 m], West Sumatra.”

Niviventer fraternus was included as a sub-species of N. rapit along with N. cameroni, but it is recognized as a distinct species here. It has not been included in any genetic studies, but multivariate analysis of morphological. traits. has. allied. it. with N. fulvescens . Monotypic.

Distribution. W Sumatra.

Descriptive notes. Head-body 162 mm, tail 231 mm, hindfoot 32-5 mm (taken from original description). No specific data are available for body weight. The Montane Sumatran White-bellied Rat is large, with spiny yet soft pelage. Itis equalin size to or larger than the Montane Bornean White-bellied Rat ( N. rapit) and smaller than the Cameron Highlands White-bellied Rat ( N. cameroni).Dorsum is dark reddish brown and lighter on sides. Venter is white, and dark brown patch can occur on chest or neck. Ears are dark brown;vibrissae are long. Tail is ¢.140% of head-body length and hairy, and it can either be unicolored (dark brown) or bicolored (dark brown above, lighter below). Dark brown stripe goes down hands, stopping before white feet. There are five digits on each foot, with fifth digit reduced with small claw. Skull is elongated and slender like other species of Niwiventer, and zygomatic plate is wider than on the Cameron Highlands White-bellied Rat and the Montane Bornean White-bellied Rat. There are four pairs of mammae: one pectoral, one post-axillary, one abdominal, and one inguinal.

Habitat. Montane forests at elevations of 1250-3500 m.

Food and Feeding. No information.

Breeding. No information.

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

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Montane Sumatran White-bellied Rat might be threatened by habitat loss at lower elevations, but no major threats are known. It occurs in Kerinci Seblat National Park and a few other protected areas.

Bibliography. Aplin (2016b), Chasen (1940), Corbet & Hill (1992), Musser & Carleton (2005), Robinson & Kloss (1916, 1918).