389.

Long-furred Arboreal Rice Rat

Oecomys trinitatis

French: Oecomys de Trinidad / German: Langhaar-Baumreisratte / Spanish: Rata arrocera arboricola de pelaje largo

Other common names: Big Arboreal Rice Rat, Long-furred Oecomys, Trinidad Arboreal Rice Rat

Taxonomy. Oryzomys trinitatis J. A. Allen & F. M. Chapman, 1893, Princes Town, Trinidad, Trinidad and Tobago.

Synonymy of O. trinitatis contains several nominal forms, such as subluteus, palmarwus, fulviventer, frontalis, helvolus, and vicencianus, some of which were described from distant localities (e.g. frontalis from Canal Zone, Panama). Originally, trinitatis was described from an island. Clearly, alpha-taxonomy in trinitatis needs additional research, and many names are available if trinomial classification is needed. Monotypic.

Distribution. SW Costa Rica, Panama, Colombia, NE Ecuador, Venezuela, Trinidad and Tobago, The Guianas, Brazil, E Peru, and NE Bolivia; exact limits unresolved.

Descriptive notes. Head-body 117-137 mm,tail 135-165 mm, ear 19-24 mm, hindfoot 25-29 mm; weight 48-74 g. The Long-furred Arboreal Rice Rat is medium large, similar to Robert’s Arboreal Rice Rat ( O. roberti) and the Unicolored Arboreal Rice Rat ( O. concolor). Dorsal fur of the Long-furred Arboreal Rice Rat is soft and dense, palpably luxuriant and lustrous, and deep (10-13 mm long over mid-rump). Head and back are dark tawny brown, commonly grading to brighter ocherous brown over cheeks and shoulders and along flanks; some individuals have bright buffy orange dorsum; and dorsal surfaces of forefeet and hindfeet are dark brownish. Venter ranges from dark grayish white and grayish white tinged with buff to rich ocherous gray. Demarcation between dorsal and ventral fur is not well-defined, occasionally marked by ocherous lateral line or ocherous tones washed along borders with grayish ventral fur. Tail ¢.118% of head-body length, dark brown and unicolored, or slightly paler below; caudal hairs are short—scalation thus visible to eye—and form slight pencil at tip. Chromosomal complement is 2n = 58, FN = 96 for populations in western Amazonia.

Habitat. Dense and mature lowland Costa Rican forest, evergreen forests with lush undergrowth, and various habitats such as tall grass and herbaceous growth in savannas and forest openings, lowland dry forest, Amazonian terra firma, and edges of flooded forests from sea level up to elevations of 2150 m.

Food and Feeding. Long-furred Arboreal Rice Rats reportedly eat fruits and small seeds.

Breeding. Nests of Long-furred Arboreal Rice Rats are located near the ground;litters have 2-4 young.

Activity patterns. L.ong-furred Arboreal Rice Rats are nocturnal and arboreal or semiarboreal.

Movements, Home range and Social organization. No information.

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

Bibliography. Bonvicino (2016b), Carleton & Musser (2015), Handley (1966), Hershkovitz (1960), Linares (1998), McPherson (1985), Patton et al. (2000), Ruelas et al. (2016).