392.

Guianan Arboreal Rice Rat

Oecomys awyantepui

French: Oecomys de I'Auyantepui / German: Guyana-Baumreisratte / Spanish: Rata arrocera arboricola de Guayana

Other common names: Guianan Oecomys

Taxonomy. Oecomys auyantepui Tate, 1939, “south slopes of Mt. Auyan-tepui, Caroni River [Bolivar], Venezuela, 3500 feet [= 1069 m].”

Taxonomy of O. awyantepui is poorly explored. Monotypic.

Distribution. E Venezuela, The Guianas, and NC Brazil.

Descriptive notes. Head-body 101-121 mm, tail 108-128 mm, ear 14-18 mm, hindfoot 23-25 mm; weight 30-48 g. The Guianan Arboreal Rice Rat is small, with luxuriant, soft, dense, and long (10-12 mm over mid-rump) pelage and sharp demarcation between dorsal and ventral pelage. Dorsum is rich ocherous tawny (nearly orange brown) in most specimens but darker— brownish tawny—in others; tops of hindfeet are dark brown to tip of digits. Venter is typically grayish white (hairs with gray bases and white tips) or uncommonly with rich ocherous overwash of gray bases; in some specimens, chin and throat are pure white, in others white strip extends along midline from throat to groin. Tail ¢.106% of head-body length and dark brown on all surfaces; caudal hairs are long, typically obscuring distal scale rows and forming conspicuous tuft at tip (c¢.6-10 mm long). Recent cytogenetic studies revealed sympatric occurrence of two different chromosomal complements: 2n = 64, FNa = 110 and 2n = 66, FNa = 114.

Habitat. Humid forest (Venezuela) and primary lowland forest on well-drained sites and in creekside or swampy settings (Guianan subregion of Amazonia), from sea level up to elevations of ¢.1100 m.

Food and Feeding. No information.

Breeding. No information.

Activity patterns. Guianan Arboreal Rice Rats are arboreal, with most specimens trapped in canopies.

Movements, Home range and Social organization. No information.

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

Bibliography. Carleton & Musser (2015), Gomes et al. (2016), Rosa (2015), Tate (1939), Voss et al. (2001), Weksler & Bonvicino (2016b).