Rattus argentiventer Robinson and Kloss 1916

Rattus argentiventer Robinson and Kloss 1916, J. Str. Br. Roy. Asiat. Soc., 73: 274.

Type Locality: Indonesia, west coast of Sumatra, Pasir Ganting.

Vernacular Names: Ricefield Rat.

Synonyms: Rattus bali Kloss 1921; Rattus brevicaudatus Horst and Raadt 1918; Rattus chaseni Sody 1941; Rattus hoxaensis Dao 1960; Rattus kalimantanensis Maryanto 2003; Rattus pesticulus Thomas 1921; Rattus saturnus Sody 1941; Rattus umbriventer Kellogg 1945 .

Distribution: Indochina: Thailand and Koh Samui off the east coast of peninsular Thailand (J. T. Marshall, Jr., 1977 a), Cambodia, C Laos (Smith et al., In Press), and Vietnam (Dang et al., 1994) in Indochina (including islands of Cham and Thô Chu off the coast of S Vietnam; Kuznetsov, 2000). Sunda Shelf: Malay Peninsula, Sumatra, Java, Borneo, Kangean Isl, and Bali. Nusa Tenggara (Lesser Sunda Isls): islands of Lombok, Sumbawa, Sangeang, Komodo, Rintja, Flores, Adonara, Lembata, Alor, Sumba, Timor, and Tanimbar. East of Indochina and the Sunda Shelf: Philippines (Cebu, Luzon, Mindoro, Negros, and Mindanao Isls; Heaney et al., 1998); Sulawesi (Musser and Holden, 1991); and one place and date of collection in New Guinea (Musser, 1973 b; Taylor et al., 1982). See Musser (1973 b) and Maryanto (2003) for details of range. Corbet and Hill (1992), followed by Helgen (2003 b), recorded the species from Seram in the Moluccas, but we cannot locate any specimens that would substantiate that occurrence, and Maryanto’s (2003) taxonomic revision of Indonesian populations does not include Seram within the distribution.

Conservation: IUCN – Lower Risk (lc).

Discussion: Rattus rattus species group. The incorrect historical association of argentiventer as a subspecies of Rattus rattus summarized by Musser (1973 b). Judged by its close morphological alliance with species that Ellerman (1941) placed in subgenus Rattus, which are mostly mainland Asian in origin, and its peculiar Indo-australian geographic distribution that is discordant with ranges of endemic species, R. argentiventer was likely inadvertently introduced into the highly distinctive murine faunas of the Sunda Shelf, Philippines, Sulawesi, Nusa Tenggara, and New Guinea from its Indochinese homeland, possibly with the spread of rice culture (Musser, 1973 b; Musser and Holden, 1991; Musser and Newcomb, 1983; Taylor et al., 1982). Rattus hoxaensis from C Vietnam, described by Dao (1960), represents R. argentiventer (Musser’s identification of specimens in ZMVNU that Dao himself identified as hoxaensis); reasons for allocating the other synonyms explained in Musser (1973 b). Geographic variation in external and cranial traits for populations from the Malay Peninsula, islands on the Sunda Shelf, Sulawesi, and Nusa Tenggara presented by Maryanto (2003). Pertinent ecological aspects of populations presented in a comparative context documented for populations on W Java (Tristiani et al., 1998, 2000; Leung and Sudarmaji, 1999). Usually found in lowlands, R. argentiventer reaches 1646 m on the slopes of Mt. Kinabalu in Sabah (Md Nor, 2001), and was caught (in 1991) in irrigated rice paddies at Nenas, highest village (1100 m) on Gunung Mutis, Timor (K. Aplin, in litt., 2004).