430.

Delicate Pygmy Rice Rat

Oligoryzomys delicatus

French: Colilargo délicat / German: Zierliche Zwergreisratte / Spanish: Rata arrocera pigmea delicada

Other common names: Delicate Colilargo

Taxonomy. Oryzomys delicatus J. A. Allen & F. M. Chapman, 1897, Caparo, Trinidad, Trinidad and Tobago.

Oligoryzomys delicatus was resurrected from O. fulvescens on molecular grounds. Currently, several nominal forms based on South American specimens are allocated under a broad and unrevised concept of O. delicatus, including O. navus (type locality in Colombia), O. tenuipes (type locality in Venezuela), and O. munchiquensis (type locality in Colombia). Oligoryzomys delicatus probably represents a composite of Andean and lowland species, but additional research is needed to clarify this. Monotypic.

Distribution. Colombia, N Venezuela, Trinidad I, the Guianas, and extreme N Ecuador.

Descriptive notes. Head—body 79-91 mm, tail 95-119 mm, ear 11-14 mm, hindfoot 20-23 mm; weight 14-28 g. The Delicate Pygmy Rice Rat is small, with yellowish brown fur above, darker and more rufous brown medially, mixed sparingly with blackishtipped hair; rump is clear yellowish rufous; sides are paler, yellowish buff; underparts are clear buff; legs are like adjoining parts of body; and dorsal surfaces of forefeet and hindfeet are yellowish white. Chromosomal complements vary from 2n = 60, FN = 72 to 2n = 62, FN = 74 and 76.

Habitat. [.ow montane forests, Paspalum (Poaceae) and lowland savannas in coastal areas, and the Venezuelan Llanos, from sea level to elevations of ¢.2000 m.

Food and Feeding. Diet of the Delicate Pygmy Rice Rat contains fruits and seeds.

Breeding. Reproductive Delicate Pygmy Rice Rats are detected year-round, with peak in rainy season.

Activity patterns. The Delicate Pygmy Rice Rat is nocturnal. It reportedly climbs and is capable of surviving periodic inundations. At Paracou, French Guiana, two specimens were encountered running on the ground through sparse weeds, and the third was climbing among dried leaves of a fallen tree.

Movements, Home range and Social organization. No information.

Status and Conservation. Not assessed on The IUCN Red List as a separate species from the Fulvous Pygmy Rice Rat ( O. fulvescens), which was classified as Least Concern.

Bibliography. August (1984), Fulhorst et al. (2004), Handley (1976), Hanson et al. (2011), Linares (1998), O'Connell (1989), Tate (1939), Utrera etal. (2000), Voss et al. (2001), Weksler & Bonvicino (2015b).