635.

Ashy-bellied Oldfield Mouse

Thomasomys cinererventer

French: Thomasomys a ventre gris / German: Graubauch-Paramomaus / Spanish: Ratén de erial de vientre cenizo

Other common names: Ashy-bellied Thomasomys

Taxonomy. Thomasomys cinererventer |. A. Allen, 1912, “crest of Western Andes (alt. 10,340 feet [= 3152 m]), 40 miles [= 64 km] west of Popayan [Popayan], Cauca, Colombia.”

This species is monotypic.

Distribution. W Andes Range of Colombia.

Descriptive notes. Head-body 126-161 mm, tail 144-172 mm, hindfoot 34-36 mm. No specific data are available for body weight. Fur of the Ashy-bellied Oldfield Mouse is quite long, soft, and lax, dark brown dorsally, with hair tipped with lighter brown; flanks are almost as dark as dorsum. Ears are rather small and brown. Venter is ash-gray, with barely perceptible wash of grayish pale yellow, moderately countershaded with respect to dorsum. Mystacial vibrissae are moderately long, extending slightly beyond posterior margin of pinnae when bent. Tail is comparatively short to moderately long (107-128% of head-body length), uniformly pale brown, covered with short hair, and without terminal pencil. Hindfoot is long. Upper surfaces of feet are pale brown, much paler than dark dorsal surfaces. Bases of nails have tufts of silvery white hairs. Hallux is short, with claw not extending beyond one-half the length of first phalanx of second digit.

Habitat. Montane forests including primary and secondary forest and heavily humanmodified areas at elevations of 1828-3152 m.

Food and Feeding. No information.

Breeding. No information.

Activity patterns. The Ashy-bellied Oldfield Mouse is probably arboreal because three individuals had Dasipsyllus gallinulae, a true bird flea, on them, perhaps obtained by temporary occupation of tree holes or othersites with bird nests.

Movements, Home range and Social organization. No information.

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

Bibliography. Allen, J.A. (1912), Escobar-Lasso et al. (2013), Gémez et al. (2004), Gémez-Laverde & Pacheco (2008a), Méndez (1971), Pacheco (2003, 2015b), Voss (2003).