639.

Wandering Oldfield Mouse

Thomasomys erro

French: Thomasomys du Sumaco / German: Napo-Paramomaus / Spanish: Raton de erial divagante

Other common names: Wandering Thomasomys

Taxonomy. Thomasomys erro Anthony, 1926, “upper slopes of Mt. Sumaco, exact altitude unknown but probably 8000-9000 feet [= 2438-2743 m], at head of the Rio Suno, a tributary of the Rio Napo, [Napo Province], eastern Ecuador.” This species is monotypic.

Distribution. E Andes Range of NC Ecuador.

Descriptive notes. Head-body 104— 152 mm, tail 131-178 mm, ear 19-21 mm, hindfoot 28-32 mm; weight 28-46 g. Dorsal fur of the Wandering Oldfield Mouse is long, soft, and lax. Dorsum is grayish brown, paler on sides; venter is washed with cream-buff, not countershaded relative to dorsum. Mystacial vibrissae are moderately long, extending slightly beyond posterior margin of pinnae when bent. Tail is long, thinly haired, and uniformly brown, and it terminates with 10-20 mm whitish tip extending as thin tuft of hair. Hindfoot is moderately long, metacarpals are similar but paler in color to dorsum, digits and ungual tuft of whitish bristles, and gap is present between thenar and hypothenar pads. Ventral base of manual claw is keeled.

Habitat. Montane forests at elevations of 1900-3600 m. Wandering Oldfield Mice have been recorded in dense secondary vegetation, subalpine rainforest, and upper montane rainforest; on the ground; in runways through wet leaflitter and mossy debris; beneath mossy logs, branches, or roots; and inside trunk of a hollow tree.

Food and Feeding. No information.

Breeding. No information.

Activity patterns. The Wandering Oldfield Mouse is nocturnal and terrestrial.

Movements, Home range and Social organization. No information.

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

Bibliography. Anthony (1926b), Musser & Carleton (1993, 2005), Pacheco (2003, 2015b, 2016i), Tirira (1999), Voss (2003).