379.

White-throated Rice Rat

Nephelomys albigularis

French: Néphélomys de Tomes / German: \Weil3kehl-Reisratte / Spanish: Rata arrocera de garganta blanca

Other common names: Tomes's Rice Rat, White-throated Nephelomys, White-throated Oryzomys

Taxonomy. Hesperomys albigularis Tomes, 1860, Pallatanga, Chimborazo, Ecuador.

Nephelomys albigularis was considered related to H. longicaudatus (currently Olgoryzomys longicaudatus). In 1894, it was placed in Oryzomys and associated with what is now Nephelomys meridensis . In the early 1960s, the scope of the species was considerably expanded to include most of the species that are now in Nephelomys and a single name, boliviae, that is currently a synonym of Euryoryzomys nitidus . From 1976 on, several of these were reinstated as separate species. Molecular phylogeny suggests that N. albigularis is a complex of at least two species, but additional research is needed to verify this. Monotypic.

Distribution. NC Ecuador (Carchi Province) S to NW Peru (Huanuco Department).

Descriptive notes. Head-body 102-162 mm, tail 138-184 mm, ear 20-24 mm, hindfoot 31-35 mm. No specific data are available for body weight. The White-throated Rice Rat is moderately large, with dorsal pelage long, dense, and soft, ranging from buffy orange grizzled with dark brown to ocherous intensely grizzled with dark brown. Venter hairs are whitish or yellowish at tips and grayish at bases, with or without small white patches in gular or pectoral regions. Ears have short hair, darker than dorsum. Mpystacial vibrissae are moderately long, extending to posterior margin of pinnae when bent. Dorsal surfaces of hindfeet have short, dispersed, whitish hairs; digits of hindfeet are covered by long whitish hairs. Tail is longer than head-body length and bicolored or weakly bicolored (few specimens with unicolored tails).

Habitat. Montane and cloud/elfin forests of the Peruvian and Ecuadorean Andes at elevations of 900-3100 m. White-throated Rice Rats have been found in primary and secondary cloud forests. In northern Peru, they inhabits very humid forests, dwelling under logs, roots, and debris.

Food and Feeding. White-throated Rice Rats are probably omnivorous.

Breeding. In Cajas (Ecuador), no pregnant females were recorded in June-October overfive years, although one lactating female was recorded, and only four of 16 males were in breeding condition. In Amazonas (Peru), females had no embryos in August, although one lactating female was recorded.

Activity patterns. White-throated Rice Rats are nocturnal and terrestrial. They can swim and use streams to escape predators.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Peruvian populations of White-throated Rice Rats could be threatened by fragmentation and rapid loss of montane forests in northern Peru (Cajamarca, Amazonas, and San Martin departments).

Bibliography. Barnett (1999), Eisenberg & Redford (1999), Musser & Carleton (1993), Pacheco et al. (2009), Percequillo (2015g), Reid et al. (2016), Thomas (1894), Tinoco (2015), Uturunco & Pacheco (2016).