New Record of the Reed Vole (Microtus fortis) from Archaeological Sites in Western Taiwan

A new record of an arvicoline species, the reed vole (Microtus fortis), which is absent from the modern fauna of Taiwan, is reported from the Wujiancuonan site of the Late Neolithic period and three Iron Age sites of Luliao, Nanshikeng, and Caiyuanjiao in western Taiwan, and this is also the first record of an extirpated rodent species in Taiwan. Based on the current evidence, the reed vole still existed in Taiwan ca. 400~600 years ago. Studied materials included two mandibles and 26 molars, most of which are fragmented or burnt, and measurements and descriptions are provided. Results were compared with previous studies of the extant reed vole and fossil records in other areas, and with the Taiwan vole (M. kikuchii). The results suggest that the body size of the Taiwan reed vole is closest to M. fortis fujianensis, the largest subspecies of reed vole. The presence of reed vole remains in archaeological layers of varied chronologies can be a reference as to the geographical and hydrological conditions and their long-term changes, since the marshy waterside habitat preference of this small mammal makes it a good indicator of ambient environments of prehistoric sites.