333.

Montane Cotton Rat

Sigmodon zanjonensis

French: Sigmodon de Zanjon / German: Berg-Baumwollratte / Spanish: Rata de algodén de montana

Taxonomy. Sigmodon zanjonensis Goodwin, 1932, “Zanjon [Quezaltenango], Guatemala, 9000 feet [= 2743 m] elevation.”

Careful review of all montane populations of Sigmodon zanjonensis in southern Mexico and northern Middle America is required to define morphological, molecular, ecological, and distributional limits. Monotypic.

Distribution. Chiapas, Mexico, E through Guatemala to at least W Honduras.

Descriptive notes. Head-body 146-163 mm, tail 104-151 mm, ear 18-22 mm, hindfoot 30-35 mm; weight 62-113 g. The Montane Cotton Ratis rather large-bodied. Dorsum, including outer surfaces of forearms and hindlegs,is dull yellowish brown, heavily grizzled by long black guard hairs, some of which are tipped yellow on rump and sides; cheeks, legs, and shoulders are slightly less darkened by black guard hairs; and belly is whitish. Eyes have indistinct yellow rings, and ears are sparsely covered with fine, white-tipped hairs. Tail is distinctly bicolored, with blackish brown on dorsal surface and white on ventral surface. Underparts are white, with gray bases to hairs visible. Karyotype is unknown.

Habitat. Montane grassland and cloud forests at elevations up to 2700 m.

Food and Feeding. The Montane Cotton Rat probably eats vegetative parts, including seeds, and seasonal insects. Assuming correct identification, it has been reported to cause severe damage to cane fields in Honduras.

Breeding. At one locality in Guatemala, males were reproductively competent in August.

Activity patterns. Montane Cotton Rats in Guatemala were trapped day and night.

Movements, Home range and Social organization. No information.

Status and Conservation. Not assessed on The [UCN Red List as a distinct species, where it is considered conspecific with Burmeister’s Cotton Rat (S. hirsutus), which is classified as Least Concern.

Bibliography. Carleton et al. (1999), Ceballos (2014a), Corley & Bradley (2014b), Gonzalez et al. (1978), Goodwin (1932a, 1958), Musser & Carleton (2005), Reid (2009).