Rattus tiomanicus Miller 1900

Rattus tiomanicus Miller 1900, Proc. Wash. Acad. Sci., 2: 212.

Type Locality: Malaysia, Pahang, Tioman Isl, off the east coast Malay Peninsula.

Vernacular Names: Malaysian Field Rat.

Synonyms: Rattus ambersoni Schwarz and Schwarz 1967; Rattus banguei Chasen and Kloss 1932; Rattus batin Robinson 1916; Rattus delirius Sody 1941; Rattus ducis (Lyon 1911); Rattus fulmineus (Miller 1913); Rattus generatius Sody 1941; Rattus jalorensis (Bonhote 1903); Rattus jarak (Bonhote 1905); Rattus jemuris Chasen and Kloss 1931; Rattus julianus (Miller 1903); Rattus kabanicus Hill 1960; Rattus kunduris Chasen and Kloss 1931; Rattus lamucotanus (Lyon 1911); Rattus lasurius Sody 1941; Rattus luxuriosus Chasen 1935; Rattus maerens (Miller 1911); Rattus mangalumis Kloss 1931; Rattus mara (Miller 1913); Rattus pauper (Miller 1913); Rattus payanus Chasen and Kloss 1931; Rattus pemanggis Chasen 1940; Rattus perhentianus Chasen 1940; Rattus pharus Hill 1960; Rattus piperis Schwarz and Schwarz 1967; Rattus rhionis (Thomas and Wroughton 1909); Rattus roa (Miller 1913); Rattus roquei Sody 1929; Rattus rumpia (Robinson and Kloss 1911); Rattus sabae Medway 1965; Rattus sebasianus Sody 1941; Rattus siantanicus (Miller 1900); Rattus sribuatensis Hill 1960; Rattus tambelanicus (Miller 1900); Rattus tenggolensis Yong 1971; Rattus terutavensis Hill 1960; Rattus tingius (Miller 1913); Rattus tua (Miller 1913); Rattus vernalus Sody 1940; Rattus viclana (Miller 1913) .

Distribution: Endemic to the Sunda Shelf and some offshore islands. Records on the Shelf are from peninsular Thailand south of Isthmus of Kra (10°30'N), the Malay Peninsula, Sumatra, Java, Bali, Borneo, Palawan (see Heaney et al., 1998, for records from the Palawan Faunal Region), and many smaller islands. Off the Sunda Shelf, R. tiomanicus is documented from Enggano Isl, southwest of Sumatra, and Maratua Arch., east of Borneo (Musser and Calafia, 1982; Musser and Heaney, 1985).

Conservation: IUCN – Lower Risk (lc).

Discussion: Rattus rattus species group. Reviewed by Musser and Califia (1982), who also summarized and provided references documenting the incorrect historical association of tiomanicus and the other synonyms listed here as subspecies of R. rattus . They also pointed out that careful study of inter-island variation among named forms of the R. tiomanicus complex is necessary before relationships among the insular populations can be discerned; more than one species may be represented in what is now viewed as R. tiomanicus . Miller’s (1942) blangorum from the Aceh region of N Sumatra, for example, was originally described as a species, then included in R. tiomanicus (Musser and Califia, 1982), and is here reinstated as a separate species (see account of R. blangorum).

Rattus mindorensis from Mindoro Isl in the Philippines; R. simalurensis from the islands of Babi, Lasia, Siumat, and Simalule, off the northwest coast of Sumatra; R. lugens from the Mentawai Arch., and R. adustus from Pulau Enggano (all islands off W coast of Sumatra), and R. burrus from some of the Nicobar Isls, are morphologically similar to the R. tiomanicus complex and should be considered part of it (Musser, 1986; Musser and Heaney, 1985). Whether they are species or island forms of R. tiomanicus can be determined within the framework of a systematic revision of the R. tiomanicus complex employing morphological and molecular data.

Distribution and ecology of R. tiomanicus on the small islands off the tip of N Sabah documented by Md Nor (1996). It is found primarily in the lowlands on Borneo but reaches 1700 m on slopes of Mt Kinabalu in Sabah (Md Nor, 2001, and references cited therein).