651.

Bukit White-bellied Rat

Niviventer bukit

French: Rat de Bukit Besar / German: Bukit-WeiRbauchratte / Spanish: Rata de vientre blanco de Bukit

Other common names: Bukit Niviventer

Taxonomy. Mus bukit Bonhote, 1903,

“Bukit Besar, Jalor, 2500 ft [= 762 m].”

Recent phylogenetic and morphological analyses split N. fulvescens into three species, N. fulvescens, N. huang, and N. bukit that are recognized here even though populations in Thailand, Cambodia, and Laosstill need to be assessed and distributional limits need clarification. A fourth species, N. ling, was also recognized but is included in N. huang here, pending further studies to validate it. Era from the Sunda region have also been attributed to N. rapit, which is restricted to Borneo here. Monotypic.

Distribution. Peninsular Thailand, Malay Peninsula, S Vietnam, Sumatra, Java, Bali, and possibly SW China and C Laos (distributional limits require clarification).

Descriptive notes. Head-body 110-122 mm, tail c.138 mm, ear 20-23 mm, hindfoot 28-32 mm; weight 60-135 g. The Bukit White-bellied Rat is small, about the size of the Himalayan White-bellied Rat ( N. niviventer) and much smaller than the Confucian White-bellied Rat ( N. confucianus) and the Indochinese Mountain White-bellied Rat ( N. tenaster).. Pelageis soft. Dorsum is dull grayish brown and dark gravel, with dull fulvous tint; grayish brown is strongest on rump. Venter is creamy white or obviously yellowish; some specimens have brown or yellowish brown spot on neck or chest. Lighter region of chest is thin compared with rest of underside. Unlike many other species of Niviventer, top offeet and toes are pale; each foot has five digits, with reduced fifth digit with small claw. Feet are gray underneath. Ears are dark brown;vibrissae are long. Tail is ¢.119% of head-body length, hairy, and bicolored, light or medium brown above and pale below. Hairs on tail are whitish and get denser toward tip; in some individuals, dorsal side of tail is paler. Skull is compact, elongated, narrow, and identical to the Limestone White-bellied Rat ( N. hinpoon). There are four pairs of mammae: one pectoral, one post-axillary, one abdominal, and oneinguinal. Chromosomal complement 1s 2n = 46, FN = 54 and 60.

Habitat. Tropical lowland forests.

Food and Feeding. The Bukit White-bellied Rat eats seeds, berries, insects, and possibly green vegetation.

Breeding. No information.

Activity patterns. The Bukit White-bellied Ratis nocturnal and mostly terrestrial, sometimes climbing vines.

Movements, Home range and Social organization. No information.

Status and Conservation. Not assessed on The IUCN Red List. The Bukit White-bellied Rat was only recently recognized as a distinct species. It has a wide distribution and probably large overall population, but it isin need of focused research on its natural history to fully understand conservation threats.

Bibliography. Balakirev et al. (2011), Bonhote (1903b), Corbet & Hill (1992), Lu Liang et al. (2015), Musser (1981a), Musser & Carleton (2005), Smith & Yan Xie (2008).