462.

Gray Rice Rat

Eremoryzomys polius

French: Oryzomys gris / German: GroRe Maranén-Reisratte / Spanish: Rata arrocera gris

Other common names: Gray Eremoryzomys

Taxonomy. Oryzomys polius Osgood, 1913, “Tambo Carrizal, mountains east of Balsas [Chachapoyas, Amazonas], Peru. Alititude about 5000 ft [= 1524 m].”

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Eremoryzomys polius is the type species of the genus. Specimens captured 29 km south of Rio Utcubamba and 38 km east of Bagua probably are the congeneric E. mesocaudis; a review of this is still pending. Monotypic.

Distribution. Known only from a few localities in NW Peru (Amazonas, Cajamarca, and La Libertad regions).

Descriptive notes. Head—body 140-172 mm, tail 168-212 mm, ear 20-25 mm, hindfoot 28-33 mm. No specific data are available for body weight. Dorsal pelage of the Gray Rice Rat is brownish olive; some adults are lighter with yellowish tones. Venteris neutral pale gray, with black or gray bases and distal part gray. Periocular ring is slightly dark. Ears are short (c.14% of head-body length). Mystical, superciliary, and genal vibrissae are medium in length and do not extend beyond posterior edges of ears. Manus and pes have long hairs that reach tips of claws or surpass them. Hindfeet have developed interdigital pads; hypothenaris rounded and ¢.33% of thenar. Thenar is elongated and posterior to first interdigital pad and very distant from hypothenar. There is no metatarsal spot. Tailis strongly bicolored and long (c.125% of head-body length), with hairs at base averaging up to 10 mm long; distal hairs cover about two scales. Female has four pairs of mammae: one postaxial pair, one pectoral, one abdominal, and one inguinal.

Habitat. Dry and premontane forest of upper and middle basins of Rio Maranon, characterized by warm and arid climate with Seasonally Dry Tropical Forest, and primary and secondary forests at elevations of 779-2205 m. The Gray Rice Rat is not known to inhabit cultivated areas.

Food and Feeding. No information.

Breeding. No information.

Activity patterns. The Gray Rice Rat is terrestrial.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Data Deficient on The IUCN Red List. Reassessment of the Gray Rice Rat is necessary because this classification included the Mediumtailed Rice Rat (E. mesocaudis).

Bibliography. Musser & Carleton (2005), Pacheco, Zeballos, Vivar & Weksler (2008), Percequillo (2015¢), Uturunco & Pacheco (2016), Weksler et al. (2006).