376.

Coastal Cordilleran Rice Rat

Nephelomys caracolus

French: Néphélomys de Caracas / German: Kiistenkordilleren-Reisratte / Spanish: Rata arrocera de la Costa

Other common names: Caracol Rice Rat, Coastal Cordillera Nephelomys, Costa Central Oryzomys

Taxonomy. Oryzomys caracolus Thomas, 1914, “Galiparé, Cerro del Avila, near Caracas, Venezuela. Alt. 6000’ [= 1829 m].”

Nephelomys caracolus was originally described in 1914 as a species of Oryzomys; from 1960 on, it was included in O. capito, Hylaeamys megacephalus, and subsequently O. albigularis . In the 1990s, studies of Venezuelan populations in the O. albigularis group, based on karyotypes and morphometrics, provided evidence for distinctiveness of O. caracolus and the other Venezuelan species of the group (e.g. O. meridensis). Patterns differed among studies, and some authors chose to retain O. caracolus and O. meridensis as subspecies of O. albigularis, suggesting need for further study of classification of Venezuelan members of the group. When members of the O. albigularis group were transferred to the new genus Nephelomys in 2006, caracolus was moved and retained as a distinct species. Monotypic.

Distribution. Cordillera de la Costa, N Venezuela.

Descriptive notes. Head-body 141 mm, tail 162 mm, ear 24 mm, hindfoot 34 mm; weight 66 g (mean values for a sample from Henri Pittier National Park). The Coastal Cordilleran Rice Rat is medium-sized, with males slightly larger than females. Dorsal pelage is long, dense, and yellowish, intensely grizzled with brown; venter is grayish to whitish, with narrow white pectoral patches variably present (in some specimens, patches are especially long, extending to gular region). Chromosomal complement is 2n = 66, FN = 90.

Habitat. Mature evergreen forest with rich subcanopy of ferns and vines and covered with abundant moss and epiphytes, disturbed forests, and drier evergreen and cloud forests with limited epiphytic cover, mostly associated with Caribbean slope of the Cordillera de la Costa, at elevations of 1050-2300 m.

Food and Feeding. The Coastal Cordilleran Rice Rat eats fruits, seeds, and invertebrates. Stomach contents revealed ¢.50% fruits ( Inga sp., Fabaceae), c.20% insect larvae, ¢.20% palm seeds, c¢.2% fungi, and c.2% Heliconia (Heliconiaceae) flowers.

Breeding. Coastal Cordilleran Rice Rats breed year-round, with peak in wet season. Sexual maturity is reached at 47 days old for males and 52 days old for females. Litters have 2-5 young. Laboratory results strongly suggest that the Coastal Cordilleran Rice Rat is monogamous.

Activity patterns. The Coastal Cordilleran Rice Rat is nocturnal and terrestrial.

Movements, Home range and Social organization. No information.

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

Bibliography. Aguilera (2016¢), Aguilera et al. (1995), Anderson (2003), Anderson & Raza (2010), Cardenas (2017), Diaz de Pascual (1988), Garcia, Delgado-Jaramillo et al. (2012), Handley (1976), Marquez et al. (2000), Moscarella (1997), Moscarella & Aguilera (1999), Moscarella et al. (2001), Musser & Carleton (2005), Percequillo (2015g), Rivas (1993, 1997), Rivas & Péfaur (1999), Thomas (1914a).