433.

Tschudi’s Pygmy Rice Rat

Oligoryzomys destructor

French: Colilargo de Tschudi / German: Tschudi-Zwergreisratte / Spanish: Rata arrocera pigmea de Tschudi

Other common names: Destructive Pygmy Rice Rat, Tschudi's Colilargo

Taxonomy. Hesperomys destructor Tschudi, 1845, farms along the Chinchao River, 900-1000 m, Huanuco, Peru.

Although the current concept of O. destructor includes several nominal forms (e.g. Hesperomys melanostoma, O. stolzmanni, O. stolzmanni maranonicus, and O. spodiurus), some recent molecular analyses indicated that this taxon is a composite of various forms. As was noted by G. G. Musser and M. D. Carleton in 2005, “distributional limits, validity of included synonyms, and relationships to other Andean species all require detailed investigation.” Bolivian populations probably belong to a new taxon, but those in north-western Argentina correspond to O. brendae . Monotypic.

Distribution. Andes from N Ecuador through Peru to C Bolivia; possibly present in S Colombia, limits unresolved.

Descriptive notes. Head-body 91-96 mm, tail 111-128 mm, ear 12-14 mm, hindfoot 23-5-24-5 mm. No specific data are available for body weight. Tschudi’s Pygmy Rice Rat is medium-sized, and paler overall, having nearly white underparts, sharply distinguished from upperparts. Dorsum is nearly ocherous, with fine linear mix of dusky colors; sides are nearly pure ocherous; head and face are scarcely different from body; underparts are soiled whitish and sharply defined, and hairs have slaty bases; feet are white; and tail is dusky above, whitish for proximal one-half below, and gradually darker to tip. Chromosomal complement for Peruvian individuals is 2n = 60, FN = 76.

Habitat. Open or poorly forested habitats in Andean slopes and Amazonian drainage and Yungas montane forest in Bolivia.

Food and Feeding. No information.

Breeding. Three pregnant Tschudi’s Pygmy Rice Rats were recorded from Bolivia in April-May, with three, four, and five embryos each.

Activity patterns. No information.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red List.

Bibliography. Anderson (1997), Carleton & Musser (1989), Gardner & Patton (1976), Gonzélez-Ittig, Salazar Bravo et al. (2010), Hanson et al. (2011), Hershkovitz (1940a), Musser & Carleton (2005), Olds & Anderson (1987), Osgood (1914b), Palma, Rodriguez-Serrano et al. (2010), Soukup (1961), Teta, Jayat et al. (2013), Weksler & Bonvicino (2015b), Weksler, Tirira et al. (2016).