638.

Ash-colored Oldfield Mouse

Thomasomys cinereus

French: Thomasomys cendré / German: Aschgraue Paramomaus / Spanish: Raton de erial cenizo

Other common names: Ash-colored Thomasomys, Olive-gray Thomasomys

Taxonomy. Hesperomys (Rhipidomys) cinereus Thomas, 1882, Cutervo, 9200’ [= 2804 m], ” Cajamarca, Peru.

Thomasomys cinenerus probably represents a species complex. Monotypic.

Distribution. SW Ecuador (Yacuri National Park) and NW Peru (W of the Rio Maranon).

Descriptive notes. Head-body 107-146 mm, tail 147, hindfoot 28-32 mm, ear 20 mm; weight 44 g. Dorsal pelage of the Ash-colored Oldfield Mouse is long, soft, and dense. Dorsum is grizzled ashy gray, hairs being slate-colored at base and white at tips, sprinkled with longer and blackish hairs. Venter is grayish white, hairs also slate-colored at base, and moderately countershaded with dorsal pelage. Mystacial vibrissae are moderately long, extending slightly beyond posterior margin of pinnae when bent; first genal (cheek) vibrissae is absent. Tail is comparatively thick and indistinctly bicolored, lacking terminal white tip. Hindfeet are moderately long, with metatarsals covered by pure white shining hairs; hands are also whitish.

Habitat. Humid montane forests or Yungas in northern Peru and forests of Aegiphila (Lamiaceae), Miconia (Melastomataceae), and Oreopanax (Araliaceae) in Ecuador at elevations of 1198-3100 m.

Food and Feeding. No information.

Breeding. Ash-colored Oldfield Mice with reproductive characteristics have been noted in late July and August (dry season).

Activity patterns. The Ash-colored Oldfield Mouse is nocturnal and terrestrial. Individuals have been found on the ground among dense shrubs and on the forest floor.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red List.

Bibliography. Cabrera (1961), Carleton (1973), Ellerman (1941), Hooper & Musser (1964a), Luna & Pacheco (2002), Moreno-Cardenas & Novillo-Gonzélez (2016), Musser & Carleton (1993, 2005), Osgood (1914b), Pacheco (2003, 2015b, 2016d), Thomas (1882, 1884), Voss (1993).