650.

Montane Oldfield Mouse

Thomasomys oreas

French: Thomasomys de montagne / German: Bolivien-Paramomaus / Spanish: Raton de erial de montana

Other common names: Montane Thomasomys

Taxonomy. 7 Thomasomys oreas Anthony, 1926, “Cocopunco, about 80 miles [= 129 km] north of La Paz, Bolivia, altitude 10,000 feet [= 3048 m].”

Considerable geographic and intraspecific variation suggests that 7. oreas represents a species group that includes at least three species, but additional taxonomic research is required. Here treated as monotypic.

Distribution. Andes from N Peru, S of the Rio Maranon, to C Bolivia.

Descriptive notes. Head-body 90-108 mm, tail 136 mm, ear 18-7 mm, hindfoot 23 25 mm. No specific data are available for body weight. Dorsal pelage of the Montane Oldfield Mouse is long, soft, Prout’s brown, and finely variegated on back with fuscous black; cheeks and sides are brighter than back; orbital ring is dusky; ears are blackish brown; and venter is pinkish buff, with gray hair basally and moderately countershaded with dorsum. Mystacial vibrissae are long, extending backward distinctly beyond pinnae when bent. Tail is bicolored, long (126-139% of head-body length), and covered with short hair, brown above and grayish below, without terminal white tip or pencil tuft. Hindfoot has clove-brown metatarsal patch, and edges and digits are grayish yellow-buff; no gap occurs between thenar and hypothenar pads. Protuberance of anus is raised.

Habitat. Eastern montane forest including upper montane elfin forests and edge of cloud forests at elevations of 2460-3650 m.

Food and Feeding. The Montane Oldfield Mouse eats seeds and arthropods.

Breeding. No information.

Activity patterns. Montane Oldfield Mice have been recorded on the ground but most often in arboreal strata.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Montane Oldfield Mouse presumably has a large overall population. Its habitat is unlikely to be declining fast, and it is probably tolerant of habitat perturbation.

Bibliography. Anderson (1993, 1997), Anthony (1926a), Cassola (2016t), Eisenberg & Redford (1999), Gardner (1976), Gardner & Patton (1976), Pacheco (2003, 2015b), Pacheco et al. (2009), Patton et al. (1990), Sahley etal. (2015), Salazar-Bravo & Yates (2007), Smith et al. (2008), Tantalean & Chavez (2004), Thomas (1920d).