393.

King Arboreal Rice Rat

Oecomys rex

French: Oecomys roi / German: Konigsbaumreisratte / Spanish: Rata arrocera arboricola real

Other common names: Regal Oecomys

Taxonomy. Oecomys rex Thomas, 1910, “R. Supinaam [= Supenaam], Lower Essequibo, Demerara [= Georgetown],” Demerara-Mahaica, Guyana.

This species is monotypic.

Distribution. E Venezuela (Bolivar State), the Guianas, and NC Brazil (Amapa, Roraima, and Amazonas states).

Descriptive notes. Head-body 121-135 mm, tail 142-168 mm, ear 17-18 mm, hindfoot 27-29 mm; weight 47-71 g. The King Arboreal Rice Rat is large and easily identified. Dorsal pelage is thick and long (10-12 mm), with very fine and luxurious texture. Upperparts are generally dark in tone, ranging from dull ocherous brown to deep chestnut, finely intermixed with black-tipped hairs over mid-dorsum and grading to brighter on flanks. Venter is uniformly dark grayish white (hairs with gray bases and white tips) in most specimens, although some have overwash of buff to ocherous on belly and dingy white on gular and inguinal regions. Tail is brown all around, and caudal hairs are short and inconspicuous without terminal pencil or tuft. Tops of forefeet and hindfeet are fuscous brown, becoming dingy white over digits.

Habitat. Humid evergreen forests in Guiana subregion of Amazonia.

Food and Feeding. No information.

Breeding. No information.

Activity patterns. King Arboreal Rice Rats are terrestrial.

Movements, Home range and Social organization. No information.

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

Bibliography. Carleton & Musser (2015), Catzeflis & Percequillo (2016), Ochoa et al. (1993).