631.

Silky Oldfield Mouse

Thomasomys bombycinus

French: Thomasomys soyeux / German: Seiden-Paramomaus / Spanish: Ratén de erial sedoso

Other common names: Silky Thomasomys

Taxonomy. Thomasomys bombycinus Anthony, 1925, Paramillo, Antioquia, Colombia; altitude 12,500 ft (= 3810 m).

Morphological differences exhibited by individuals attributed to 7. bombycinus suggest that it might be polytypic, but more taxonomic research is needed. Monotypic.

Distribution. W Andes Range in NW Colombia.

Descriptive notes. Head-body 112-130 mm, tail 133 mm, ear 20 mm, hindfoot 26-30 mm. No specific data are available for body weight. Fur of the Silky Oldfield Mouse is long, soft, and silky. Dorsum varies between fuscous and clove-brown, sprinkled with black-tipped hair; sides are paler; ears are clove-brown; and hands and feet are pale brown. Venter is cinnamon-buff to tawny-olive, smoothly transitioned from darker color of flanks, not counter shaded. Mystacial vibrissae are moderately long, extending slightly beyond posterior margin of pinnae when bent. Tail is relatively short (99-124% of head-body length), drab above, somewhat lighter below, and thinly haired. Hindfoot is moderately short and narrow, without metatarsal patch.

Habitat. Probably moist montane habitats including forest and paramo at elevations of 2800-3800 m.

Food and Feeding. No information.

Breeding. No information.

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

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Data Deficient on The IUCN Red List.

Bibliography. Anthony (1925), Eisenberg (1989), Delgado, Gémez-Laverde & Pacheco (2008), Pacheco (2015b).