497.

Yellowish Rice Rat

Aegialomys xanthaeolus

French: Oryzomysjaune / German: Gelbe Reisratte / Spanish: Rata arrocera dorada

Other common names: Yellowish Aegialomys, Yellowish Oryzomys

Taxonomy. Oryzomys xanthaeolus Thomas, 1894, “Tumbez [= Tumbes], N. Peru.”

Aegialomys xanthaeolus is the type species of the genus. Monotypic.

Distribution. W Ecuador and extreme NW Peru.

Descriptive notes. Head-body 105-110 mm, tail 118-176 mm, hindfoot 27-33 mm, ear 20-24 mm; weight 50-73 g. The Yellowish Rice Rat has a moderately complex pattern of sexual dimorphism,

including males larger than females in continental islands populations; however, studies on non-geographical variation assumed that the Yellowish Rice Rat represented a species complex (i.e. including Baron’s Rice Rat, A. baron, and the Ica Rice Rat, A. ica). Furis soft, long, lax, dense, and woolly, with pale yellow wool and cover hairs and brown guard hairs. Dorsum is copper, weakly grizzled with brown. Venteris grayish cream, with gray-based and whitish tipped hair. Dorsal surface of hindfoot is covered by white hair and short and sparse ungual tufts (about one-half the size of claw), and pads are developed with thenar closest to hypothenar. Ears have very long hair, more abundant externally, brown with golden apex and internally more golden than brown. Tail is longer than head-body length, conspicuously bicolored (dark gray above and unpigmented below), and hirsute, with c.16 large scales/cm. Anteromedian flexid of M, is typically absent.

Habitat. Humid habitats of north-central Ecuador to drier areas of north-western Peru, including dry forest, desert, inter-Andean valleys, and lomas at elevations of 500-1800 m. The Yellowish Rice Rat is well-adapted to secondary vegetation, plantations, and cultivated areas.

Food and Feeding. No information.

Breeding. No information.

Activity patterns. The Yellowish Rice Rat is nocturnal and terrestrial.

Movements, Home range and Social organization. The Yellowish Rice Ratis solitary.

Status and Conservation. Classified as Least Concern on The IUCN Red List. A reassessment of the Yellowish Rice Rat is necessary because in this classification included Baron’s Rice Rat and the Ica Rice Rat before they were elevated to distinct species.

Bibliography. Percequillo (2015k), Prado & Percequillo (2011, 2016, 2017), Thomas (1894).