431. Grayish Pygmy Rice Rat Oligoryzomys griseolus French: Colilargo grisonnant / German: Graue Zwergreisratte / Spanish: Rata arrocera pigmea gris Other common names: Grizzled Colilargo Taxonomy. Oryzomys griseolus Osgood, 1912, west of Paramo de Tama, 6000-7000 ft (= 1830-2130 m), upper Tachira River, Tachira State, Venezuela. Phylogenetic relationships of O. griseolus to similar forms in northern South and Central America require additional research. Monotypic. Distribution. Extreme W Venezuela (Tachira Andes); maybe adjacent NE Colombia. Descriptive notes. Head-body 76-85 mm, tail 96-114 mm, hindfoot 20-23 mm. No specific data are available for body weight. Upperparts of the Grayish Pygmy Rice Rat have abundant mix of black-tipped hairs; forehead and sides of face are gray. Upperparts are pale clay; small preauricular tuft of ocherous-tipped hairs is usually present. Underparts are mostly clay to ocherous buff, almost or concealing slaty bases of hairs; middle of chin and throat are white or whitish to bases of hairs; feet are white; outer sides of tarsal joints are broadly dusky; and tail is dusky above and dull whitish below. There are three pairs of mammae. Habitat. High montane forest and grassy swamps (paramo). Food and Feeding. No information. Breeding. No information. Activity patterns. No information. Movements, Home range and Social organization. No information. Status and Conservation. Classified as Least Concern on The IUCN Red List. Nevertheless, the Grayish Pygmy Rice Rat is considered uncommon, with reported trap success less than 5%. Bibliography. Cassola (2016z), Gutiérrez et al. (2015), Handley (1976), Linares (1998), Soriano et al. (1999), Weksler & Bonvicino (2015b).

Published as part of Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Cricetidae, pp. 204-535 in Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona :Lynx Edicions on page 433, DOI: 10.5281/zenodo.6707142