638.

Berdmore’s White-toothed Rat

Berylmys berdmorei

French: Rat de Berdmore / German: Berdmore-Weil 3 zahnratte / Spanish: Rata de dientes blancos de Berdmore

Other common names: Berdmore's Berylmys, Small White-toothed Rat

Taxonomy. Mus berdmorei Blyth, 1851,

Mergui (South Tenasserim), South Burma (= Myanmar).

Polytypic, but number, diagnoses, and ranges of subspecies require review.

Distribution. SC China (Yunnan), SE Myanmar, Thailand, N Laos, and Vietnam.

Descriptive notes. Head-body 190- 255 mm, tail 149-192 mm, ear 20-29 mm, hindfoot 37-46 mm; weight 158-300 g. The Berylmys genus has the following characters: dorsum is dense and crisp iron-gray, and venter is whitish—both well-delineated; braincase is dorsally triangular; nasolacrimal canalis very inflated; low and weakly developed ridges demarked interand postorbital regions; incisive foramina usually reach level of upper molar rows; there is short palatal bridge at the level of M?; there are no sphenopterygoid vacuities that breach pterygoid fossae; upper incisors are slightly proodont or orthodont; enamel of upper and lower incisors might be white, creamy, pale, or orange;M’ and M,are relatively small; cusps t3, t6,and t9 occur on M'; cusps t6 and t9 on M* are nearly merged, with indistinct or lacking central cusps; lamina on m, are small and narrow; and anterolabial cusps are absent on M,. Berdmore’s White-toothed Ratis chunky and medium-sized; dorsum is iron gray, and venteris white; tail is shorter than head-body length; skull is stocky, with high braincase; tympanic bulla are large and inflated compared with skull length; incisors are slightly proodont; and frequency of antero-labial cusps is small on M,. There are ten pairs of mammae: one pectoral, two post-axillaries, and two inguinal pairs.

Habitat. Primary forest, especially in upland habitats and swampy regions, from sea level to elevations of ¢.1400 m. Berdmore’s White-toothed Rat normally does not occur nearby human habitations or in the city.

Food and Feeding. Berdmore’s White-toothed Rat is probably omnivorous.

Breeding. No information.

Activity patterns. Berdmore’s White-toothed Rats are nocturnal and spend the day in their burrows.

Movements, Home range and Social organization. Male and female Berdmore’s Whitetoothed Rats can be found in burrows that are several meters long and have twoentrances and a central chamber.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Berdmore’s White-toothed Rat is not under special treat because it has wide distribution, including national parks and anthropic habitats; however, there is a clear lack of data concerning its ecology, phylogeography, and taxonomy. It is considered an agricultural pest in Thailand and Vietnam.

Bibliography. Aplin, Brown et al. (2003), Corbet & Hill (1992), Dang HuyHuynh et al. (1994), Kuznetsov (2000), Marshall (1977a, 1977b), Musser & Newcomb (1983), Robinson et al. (1995), Wang Yingxiang (2003), Yang Guangrong & Wu Delin (1979), Zhang Yongzu et al. (1997).