134.

Tarabundi Vole

Microtus oaxacensis

French: Campagnol d'Oaxaca / German: Oaxaca-Wihlmaus / Spanish: Topillo de Tarabundi

Other common names: Oaxacan Vole

Taxonomy. Microtus oaxacensis Goodwin, 1966, “evergreen rainforest at Tarahundi, a ranch near the village of Vista Hermosa, about halfway between Comaltepec and Valle National, 135 kilometers north of Oaxaca city, District of Ixtlan, Oaxaca, Mexico, altitude, about 5000 feet [= 1524 m].”

This species is monotypic.

Distribution. Known from relatively few sites in semi-isolated mountain range in Ixtlan District, Oaxaca State, Mexico, that is bounded to N by Rio Santo Domingo, to W & S by Rio Grande, and to E by coastal plain of Gulf of Mexico.

Descriptive notes. Head-body 112-127 mm, tail 31-40 mm, ear 12-15 mm, hindfoot 20-23 mm; weight 31-46 g. The Tarabundi Vole is medium-large, with blackish brown dorsal pelage of black hairs with brownish orange tips. Belly hairs are lighter; pelageis generally long and woolly. Feet are black and contrast with white nails. One inguinal and two pectoral pairs of mammary glands are characters shared with only the Guatemalan Vole ( M. guatemalensis) among all microtines. The Tarabundi Vole has five triangles on last upper molar, and the Guatemalan Vole has three. Skull is long, flat, and less angular than that of other species of Microtus . Incisive foramina are narrow and short, and bullae are rounded and relatively small. Chromosomal complement is 2n = 30, FN = 56.

Habitat. Cloud forest and ecotone between cloud and pine ( Pinus, Pinaceae) forests at elevations of 2100-2500 m. Where Tarabundi Voles have been found, undergrowth of vegetation reflects mesic habitat and included strawberries ( Fragaria sp., Rosaceae) and grasses.

Food and Feeding. The Tarabundi Vole likely eats grasses, forbs, and other vegetation.

Breeding. Tarabundi Voles have been found in breeding condition in February and July. A single record indicated a litter size of one young.

Activity patterns. No information.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Endangered on The IUCN Red List. The Tarabundi Vole occurs in less than 5000 km?, and its habitat is highly fragmented and experiencing substantial negative impacts.

Bibliography. Bradley, Ammerman et al. (2014), Frey & Cervantes (1997b), de Grammont & Cuarén (2008c), Musser & Carleton (2005), Sanchez et al. (1996).