330.

Toltec Cotton Rat

Sigmodon toltecus

French: Sigmodon tolteque / German: Tolteken-Baumwollratte / Spanish: Rata de algodén de los Tolteca

Taxonomy. Hesperomys loltecus Saussure, 1860, “la Cordilieére de la province de VéraCuz,” Mexico . Clarified by W. W. Dalquest in 1953 to near Mirador, Veracruz, Mexico.

Sigmodon toltecus was considered a subspecies of S. hispidus until molecular analyses documented strong genetic divergence and cladistic separation. Assignment of microdon, saturatus, and furvus was confirmed by molecular analyses, although subspecfic rank needs evaluation. Note erroneous IUCN assignment of solus (synonym of S. hispidus) and villae (synonym of S. zanjonensis). Monotypic.

Distribution. E Mexico from SE Tamaulipas S across Isthmus of Tehuantepec into Yucatan Peninsula, W Chiapas, Belize, N Guatemala, and NW Honduras.

Descriptive notes. Head-body 138-227 mm, tail 112-165 mm, ear 16-24 mm, hindfoot 29-41 mm; weight 70-133 g. The Toltec Cotton Rat is medium-sized, with gray dorsal pelage streaked with mix of blackish or dark brownish and buffy hairs; underparts are whitish to orange-brown;sides are slightly paler than dorsum; and tail is darkly colored and sparsely haired, with large annular scales. Skull is long and narrow, but determination of diagnostic characteristics require comparative analyses, especially relative to sister species, the Hispid Cotton Rat (S. hispidus). Chromosomal complement is 2n = 52, FNa = 52.

Habitat. Humid coastal, foothill, and montane perennial grasslands, often near edge of water in subhumid and humid subtropical zones east of the Sierra Madre Oriental, and agricultural areas, such as sugarcane fields, from sea level to elevations of ¢.1000 m. Food and Feeding. Diet of the Toltec Cotton Rat consists primarily of green plant material and fungi, but some seeds, insects, and even bird eggs are eaten opportunistically.

Breeding. Litters of Toltec Cotton Rats had 2-7 young (mean 3-3) in a population in Veracruz, Mexico. Gestation is ¢.27 days, and young are highly precocial at birth.

Activity patterns. The Toltec Cotton Ratis primarily diurnal or crepuscular, with nocturnal activity depressed; temporal activity of adult males and females differs.

Movements, Home range and Social organization. Maximum densities have been estimated at 51 ind/ha in autumn, with a minimum of 25 ind/ha in summer.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Toltec Cotton Rat has a wide distribution and presumably large overall population; it occurs in several protected areas and lacks any known conservations threats.

Bibliography. Bailey (1902), Bangs (1903b), Bradley et al. (2008), Carleton et al. (1999), Carroll et al. (2005), Cassola (2016e), Castro-Arellano & Lacher (2009), Ceballos (2014a), Dalquest (1953), Engilis et al. (2012), Goodwin (1958), Hall (1951), Hall & Dalquest (1963), Musser & Carleton (2005), Peppers & Bradley (2000), Platt et al. (2009), Reid (2009), de Saussure (1860), Westerman & Bradley (2014).