673.

White-footed Indochinese Rat

Rattus nitidus

French: Rat soyeux / German: Himalaya-Ratte / Spanish: Rata de Indochina de pies blancos

Other common names: Himalayan Field Rat

Taxonomy. Mus nitidus Hodgson, 1845,

“central regions

of

Nepal.”

Rattus nitidus is in the R. norvegicus species group;it is morphologically similar to R. nor vegicus and its sister species. Monotypic.

Distribution. N & NE India, E Nepal, extreme W & E Bhutan, W, N & E Myanmar, C, SC & SE China (including Hainan I), N Thailand, Laos, Vietnam (including offshore Cat Ba I), and probably E Bangladesh. Introduced to the Philippines (Luzon I), C Sulawesi, Seram I, NW New Guinea, and Palau, although it may be more widely introduced.

Descriptive notes. Head—body 148-180 mm, tail 135-206 mm, ear 21 mm, hindfoot 32-36 mm; weight 110-140 g. Males (136 g) are heavier on average and have longer hindfeet than females (114 g); northern populations also seem to be larger than southern populations. The White-footed Indochinese Rat is medium-sized and very similar to the Brown Rat ( R. norvegicus), with similarly robust body and broad nose (most easily distinguished by its proportionally shorter hindfeet and its overall smaller body). Pelage is soft, short, and thick. Dorsum generally consists of dark grayish row with mix of pale brown and black-tipped hairs, although shades of brown vary: sides are somewhat lighter. Venter is duller grayish brown and not sharply demarcated from dorsal pelage. Feet are long and white throughout, with pearly luster dorsally. Ears are rounded and lighter brown; vibrissae are long and stiff. Tail is 91-105% of head-body length and usually unicolored, brown orslightly paler ventrally. Skull has long rostrum and robust structure, similar to that of the Brown Rat. The blood fluke Schistosoma japonicum and various trematodes, cestodes, nematodes, ticks, mites, fleas, and lice have been recorded from the Whitefooted Indochinese Rat. There are six pairs of mammae: three axillary and three inguinal. Chromosomal complement is 2n = 42, FN = 62.

Habitat. Most forest types, cropland, and human settlements at elevations of 686— 2740 m. Native habitats of White-footed Indochinese Rats might be close to streams and rivers, which they regularly enter, and they seem to prefer disturbed habitat when available. They are less common in villages, usually being replaced by the Roof Rat ( R. rattus).

Food and Feeding. The White-footed Indochinese Rat eats vegetation and animal foods. It eats many crops, such as rice, wheat, corn, and potatoes, which makes it a very prominent agricultural pest.

Breeding. Reproduction occurs in March—-November, with peaks in March-April and August—September. After the breeding season, body mass decreases in both sexes but can rapidly increase to the original mass before breeding. Litters have 4-15 young (mean eight), and captive born individuals average 7 g at birth.Young are weaned after 25-30 days. Females will produce 1-3 litters/year, although captive individuals can produce up

to b litters/year, with an average of 34-7 days between births. Females reach sexual maturity at c.119 days; males reach maturity faster at 63-80 days. Life span is 13-15 months.

Activity patterns. The White-footed Indochinese Ratis active day and night. It is primarily terrestrial, although it will climb if necessary and can swim well and does so regularly. Nests are usually made around houses when near agricultural areas, but the species digs burrows in areas without human settlements.

Movements, Home range and Social organization. Densities in plains of western Sichuan were 0-7-11-3 ind/ha. The same study found that 90% of individuals moved 39 m (males) and 35 m (females) from their activity centers, and 10% dispersed 115 m (males) and 140 m (females). Abundance peaks in May-June and September—October (at c.10 ind/ha), corresponding to ripening of wheat and just after rice harvest, respectively. White-footed Indochinese Rats shift habitat use based on food availability.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Whitefooted Indochinese Rat has a very wide distribution, is common, and is considered an agricultural and urban pest throughoutits distribution, both native and introduced; cereal grains are most affected.

Bibliography. Aplin, Brown et al. (2003), Aplin, Chesser & ten Have (2003), Aplin, Lunde & Molur (2016b), Balakirev & Rozhnov (2012), Duncan & Van Peenen (1971), Francis (2008), He Yixun etal. (2001), Johnsingh & Manjrekar (2015), Musser & Carleton (2005), Pakdeenarong et al. (2014), Smith & Yan Xie (2008), Wei Lei et al. (2010), Yang Yuemin et al. (1999), Zeng Zongyong, Ding Weijun, Luo Mingshu et al. (1996), Zeng Zongyong, Ding Weijun, Yang Yuemin et al. (1996), Zeng Zongyong, Luo Mingshu et al. (1997), Zeng Zongyong, Yang Yuemin et al. (1999).