391.

Unicolored Arboreal Rice Rat

Oecomys concolor

French: Oecomys de Wagner / German: Einfarb-Baumreisratte / Spanish: Rata arrocera arboricola unicolor

Other common names: Natterer's Oecomys, Unicolored Oecomys

Taxonomy. Hesperomys concolor Wagner, 1845, “Flusse Curicuriari im nordwestlichen Brasilien.” Interpreted by P. Hershkovitz in 1960 as “Rio Curicuriari, an affluent [= tributary] of the upper Rio Negro, entering from the right below Sao Gabriel [da Cachoeira], Amazonas, Brazil.” This species is monotypic.

Distribution. E Colombia, S Venezuela (S Orinoco River), and NW Brazil (N of Amazonas River).

Descriptive notes. Head—body 115-141 mm, tail 137-160 mm, ear 15-20 mm, hindfoot 26-29 mm; weight 41-80 g. The Unicolored Arboreal Rice Rat is medium-to-large, with relatively long tail (c.118% of head-body length) and short pelage (5-7 mm over mid-rump). Dorsum varies from dull fulvous brown to brighter ocherous tawny, especially over shoulders and cheeks. Venter is wholly dull white in most specimens, with strong overwash of buff-tipped to ocherous tipped hairs in other specimens, or with small to broad expanses of gray over mid-abdomen in others; dorsal and ventral pelage contrasts weakly in the last two venter color types. Pinnae are dark brown, usually contrasting with adjacent upperparts. Tail is brown to dark brown all around for most of its length, mottled beneath near base; short caudal hairs expose scale rows for most of tail length, without formation of terminal pencil.

Habitat. Lowland rainforest at elevations above 400 m.

Food and Feeding. No information.

Breeding. No information.

Activity patterns. No information.

Movements, Home range and Social organization. No information.

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

Bibliography. Carleton & Musser (2015), Carleton et al. (2009), Costa et al. (2016), Hershkovitz (1960), Wagner (1845).