401.

Atlantic Forest Arboreal Rice Rat

Oecomys catherinae

French: Oecomys de Santa Catarina / German: Atlantische Baumreisratte / Spanish: Rata arrocera arbéricola de bosque atlantico

Other common names: Atlantic Forest Oecomys

Taxonomy. Oecomys catherinae Thomas, 1909, “Joinville, Santa Catherina [= Catarina], S. Brazil.”

Morphological and molecular variation contained in the current concept of O. catherinae 1s noteworthy; status of bahiensis deserves attention. Monotypic.

Distribution. E & EC Brazil.

Descriptive notes. Head-body 121-139 mm, tail 143-165 mm, ear 11-29 mm (mean 15), hindfoot 28-30 mm; weight 47-71 g. The Atlantic Forest Arboreal Rice Rat is moderately large and slightly larger than the Long-furred Arboreal Rice Rat ( O. trinitatis). Dorsal pelage is lush, thick (12-14 mm at dorsum), sleek, bright, and brownish orange to tawny chestnut. General impression of underparts is dark grayish white; ventral hairs have dark to slate gray bases, usually tipped with white; and variations include streaks or patches of buffytipped hairs on chest and abdomen and creamy hairs confined to throat. Demarcation between dorsum and ventrum is weakly defined. Flank is slightly lighter than dorsum. Tail is dusky brown all around for most of its length, paler beneath toward base; caudal hairs are short, revealing fine scale rows and not forming discrete tuft. Larger mystacial vibrissae reach ¢.45 mm in length, surpassing ears when extended backward. Chromosomal complement is 2n = 60, FN = 62 and 64.

Habitat. Atlantic coast forests including dense rainforest and open rainforest, and semideciduous forest in savanna forest mosaic (i.e. gallery forest settings in Cerrado biome) from sea level to elevations of ¢.770 m. In Caatinga biome, the Atlantic Forest Arboreal Rice Rat was trapped in humid forest enclaves with emergent trees 10-20 m high and predominance of species of Fabaceae and Poaceae .

Food and Feeding. No information.

Breeding. No information.

Activity patterns. No information.

Movements, Home range and Social organization. In Atlantic Forest fragments in Rio de Janeiro State, Brazil, the Atlantic Forest Arboreal Rice Rat was more abundant in fragments near peri-urban areas.

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

Bibliography. Asfora et al. (2011), Carleton & Musser (2015), Costa, Bonvicino et al. (2016), Flores (2010), Hershkovitz (1960), da Rocha, PA. et al. (2015), Vieira et al. (2009).