313.

Nelson's Big-toothed Deermouse

Megadontomys nelsoni

French: Péromyscus de Nelson / German: Nelson-Grof 3zahn-Hirschmaus / Spanish: Ratdn ciervo de dientes grandes de Nelson

Other common names: Nelson's Giant Deer Mouse

Taxonomy. Peromyscus (Megadontomys) nelsoni Merriam, 1898, Jico, 6000 ft (= 1830 m), Veracruz, Mexico .

Megadontomys nelsoni was recognized as subspecies of M. thomasi but elevated to species status. The validity of the genus Megadontomys 1s still much debated. Monotypic.

Distribution. Restricted to high-elevations of Sierra Madre Oriental in CW Veracruz, E Puebla, and N Oaxaca, Mexico.

Descriptive notes. Head-body 132-146 mm, tail 170-172 mm, ear 20-21 mm, hindfoot 32-35 mm; weight 57 g. Nelson’s Big-toothed Deermouse is large, approaching a medium-sized woodrat ( Neotoma). It is similar in most characteristics to the Oaxacan Big-toothed Deermouse (M. cryophilus) and Thomas’s Big-toothed Deermouse ( M. thomasi), but there are relatively strong genetic differences among the three species. Morphologically, Nelson's Big-toothed Deermouse bridges the gap between the Oaxacan Big-toothed Deermouse and Thomas’s Big-toothed Deermouse, butit is considered closer to the latter.

Habitat. Known only from cloud forests and pine ( Pinus, Pinaceae) and oak ( Quercus, Fagaceae) forests, with thickly vegetated areas and dense understories of vines and shrubs, at elevations of 2000-3500 m.

Food and Feeding. Diet probably consists of seeds and other vegetation.

Breeding. Reproduction occurs in March-November, with litters of 2-3 young.

Activity patterns. Nelson's Big-toothed Deermouse is presumably nocturnal.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Endangered on The IUCN Red List. Endemic Nelson’s Big-toothed Deermouse has decreasing populations.

Bibliography. Bradley et al. (2007), Carleton (1989), Musser (1964), Pena & Hernandez (2014), Platt et al. (2015), Werbitsky & Kilpatrick (1987).