417.

Alfaro’s Rice Rat

“ Handleyomys” alfaroi

French: Oryzomys dAlfaro / German: Alfaro-Reisratte / Spanish: Rata arrocera de Alfaro

Other common names: Alfaro’s Oryzomys

Taxonomy. Hesperomys (Oryzomys) alfaroi J. A. Allen, 1891, San Carlos, Alajuela Province, Costa Rica.

Several forms have been subsumed under alfaror including gracilis, palatinus, incertus, palmirae, dariensis, intagensis, gloriaensis, and agrestis . Most of them were proposed originally as subspecies of alfaroi, but comprehensive taxonomic revision is needed to clarify a rationale trinomial classification. Monotypic.

Distribution. E & S Mexico through Middle America to NW Colombia and SW Ecuador.

Descriptive notes. Head-body 90-106 mm, tail 89-101 mm, ear 14-17 mm, hindfoot 25-28 mm; weight 20-32 g. Alfaro’s Rice Rat is a small-sized species of “ Handleyomys,” characterized by dull yellow-brown to dark reddish brown dorsum;sides are ocherous to orangish; and venteris grayish white. Furis short (less than 5 mm); ears are usually thinly lined with blackish or orangish hair, sometimes appearing almost hairless. Tail is uniformly dark or weakly bicolored over proximal one-half and then dark to tip. Chromosomal complement is 2n = 60, FN = 104.

Habitat. Evergreen forests from near sea level to elevations of ¢.2500 m. In Costa Rica, Alfaro’s Rice Rat is found on heavily forested mountain slopes in the humid lower tropical zone. Nicaraguan captures came from diverse habitats, including grasslands, woodlands, and along rivers.

Food and Feeding. No information.

Breeding. Two pregnant Alfaro’s Rice Rats had three and five embryos; one of them was recorded in March.

Activity patterns. Alfaro’s 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. Goldman (1918a), Haiduk et al. (1979), Hall & Kelson (1959), Jones & Engstrom (1986), Musser & Carleton (2005), Timm, Matson et al. (2016), Weksler (2015a).