Rattus andamanensis

670.

Indochinese Forest Rat

Rattus andamanensis

French: Rat d'Indochine / German: Sikkim-Ratte / Spanish: Rata de bosque de Indochina

Other common names: Sikkim Rat

Taxonomy. Mus (Leggadar) andamanensis Blyth, 1860,

South Andaman Island, An- daman Islands, India.

Rattus andamanensis was previously known as R.sikkimensis and R. remotus, but the oldest name available is R. andamanensis. Its placement in species groups of Rattus 1s uncertain, but it is sister to a clade containing the R. rattus and R. exulans species groups. Monotypic.

Distribution. E Nepal, NE India, Bhutan,

S China (including Hong Kong and Hainan I), N &E Myanmar, NC Thailand, N & E [Laos, Vietnam, S Cambodia, Andaman Is (North Andaman, Interview, Middle Anda- man, Long, Henry Lawrence, Havelock, South Andaman, and Little Andaman), Car Nicobar, and a few Is off the E coast of peninsular Thailand (Koh Tao, Koh Phangan, Koh Samui, and Koh Kra); perhaps in N Bangladesh.

Descriptive notes. Head—body 155-200 mm, tail 185-240 mm, ear 23-25 mm, hindfoot 32-37 mm; weight 100-150 g. The Indochinese Forest Rat is moderately large and somewhat similar to the Roof Rat (R. rattus), with more plantar pads, proportionately longertail, and longer guard hairs. Pelage is long and thick, with prominent black guard hairs (more prominent along midline of back). Dorsum is varying shades of brown, with orangish hue andpale brown and black-tipped hairs and guard hairs mixed throughout. One specimen from Hong Kong had white patches on snout and cheeks, which has been recorded in other specimens. Venter is creamy white, and some individuals have spots of grayish based hairs or reddish brown chest patch; ventral pelage is sharply demarcated from dorsal pelage. Feet are covered with mix of light and dark hairs dorsally, up to digits, which are white. Ears are relatively large and similar to dorsal pelage in color; vibrissae are exceptionally long and thick. Tail is ¢.120% of head-body length and generally brown dorsally and ventrally, although some individuals have been reported from Hainan with white-tipped tails. Skull is robust, with comparatively broad rostrum and small bullae. Some species of mites (Laelaps nuttali, L. echidninus, Lyponissoides, and Ornithonyssus bacoti) and fleas (Xenopsylla cheopis) have been recorded on Indochinese Forest Rats. There are six pairs of mammae: three axil- lary and three inguinal pairs. Chromosomal complement is 2n = 42, FN = 64 and 70.

Habitat. Various forest and forest-edge habitats and secondary and modified habitats at elevations up to 2000 m. The Indochinese Forest Rat apparently is also found in agricultural lands, scrubland, and around houses.

Food and Feeding. No information.

Breeding. No information.

Activity patterns. Indochinese Forest Rats are nocturnal and highly arboreal.

Movements, Home range and Social organization. Densities of the Indochinese Forest Rats increase with habitat complexity.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Indochinese Forest Rat has a wide distribution and is relatively common, being found in numerous protected areas. It is not known to be anurban or agricultural pest but might may threaten by poisoningand trapping for other pest species such as the Roof Rat.

Bibliography. Aplin, Brown et al. (2003), Aplin, Frost et al. (2016), Aplin, Suzuki et al. (2011), Balakirev & Rozhnov (2012), Francis (2008), Fuehrer et al. (2012), Johnsingh & Manjrekar (2015), Kudalkar (2016), Musser & Carleton (2005), Smith & Yan Xie (2008).