443.

San Javier's Pygmy Rice Rat

Oligoryzomys brendae

French: Colilargo de Brenda / German: San-JavierZwergreisratte / Spanish: Rata arrocera pigmea de San Javier

Other common names: Brenda's Colilargo, San Javier Colilargo

Taxonomy. Oligoryzomys brendae Massoia, 1998, Cerro San Javier, 1000 m, Tucuman, Argentina.

Most available literature refers to O. brendae as O. longicaudatus . Monotypic.

Distribution. Highlands from Jujuy and Salta to La Rioja provinces, NW Argentina; it may occur in S Bolivia, limits unresolved.

Descriptive notes. Head—body 78-101 mm (mean 90 mm), tail 112-135 mm, ear 17-20 mm, hindfoot 24-28 mm; weight 12-34 g. San Javier's Pygmy Rice Rat is large, with orangish brown dorsum and somewhat grizzled appearance; ventral hairs are basally gray and whitish to ocherous at tips; ears are short, rounded, and dark brown;tail is longer than head-body length and sharply bicolored; skull is relatively robust, with short and broad rostrum, well-expanded zygomatic arches, and inflated and broad braincase; interorbital constriction is narrow and hourglass-shaped, with slightly defined supraorbital ridges; and incisive foramina are relatively long, posteriorly extended to anterior border of M'. Chromosomal cmplement is 2n = 58, FN = 74.

Habitat. Forested and highland grassland environments of Yungas at elevations of 700-2900 m. San Javier's Pygmy Rice Rat was restricted to isolated humid ravines in xeric Dry Chaco and Monte Desert formations.

Food and Feeding. One San Javier's Pygmy Rice Rat had insects and vegetation in its stomach.

Breeding. Non-reproductive males and females were reported in dry season (May-September). Young were found in dry season, suggesting that most reproduction occurred in wet season (November—February).

Activity patterns. No information.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Data Deficient on The IUCN Red List. Other than deforestation, no major threats apparently face San Javier’s Pygmy Rice Rat, but there is no information on its abundance and population trends.

Bibliography. Crespo (1974), Diaz et al. (1997, 2000), Ferro & Barquez (2017), Gamboa et al. (2016), Gonzalez-Ittig et al. (2014), Jayat & Ortiz (2010), Jayat & Pardinas (2008a), Mares, Ojeda & Barquez (1989), Mares, Ojeda, Braun et al. (1997), Ojeda & Mares (1989), Ojeda, Barquez et al. (2008), Sandoval et al. (2015), Teta, Jayat et al. (2013), Weksler & Bonvicino (2015b).