651.

Cajamarca Oldfield Mouse

Thomasomys praetor

French: Thomasomys du Cajamarca / German: Cajamarca-Paramomaus / Spanish: Raton de erial de Cajamarca

Other common names: Cajamarca Thomasomys

Taxonomy. Oryzomys praetor Thomas, 1900, “Eastern slope of Paramo between San Pablo and Cajamarca, Peru. Alt. 4000 metres.” This species is monotypic.

Distribution. W slopes and inter-Andean valleys of N Andes in Peru between Huancabamba Depression and Rio Maranon.

Descriptive notes. Head-body 161-187 mm, tail 180 mm (holotype), ear 23-25 mm, hindfoot 35-38 mm. No specific data are available for body weight. Fur of the Cajamarca Oldfield Mouse is long (hairs on mid-back 13-15 mm), soft, dense, and thick. Dorsum is olivaceous grayish, darkened on middle and posterior back; head, cheeks, shoulders, and sides are yellowish gray; and venter is buffy white, with slate-based hairs. Fur above ears is blackish brown and has conspicuous white post-auricular patch. Fur above metatarsals is silvery white. Mystacial vibrissae are moderately long, extending slightly beyond posterior margin of pinnae when bent. Hindfoot is long, with long hallux extending to interphalangeal joint of second digit, or moderately long not reaching that joint. Fifth digit of pes is moderately long, with claw extending close to base of claw of fourth digit. Tail is relatively short (107-116% of head-body length), incipiently bicolored, uniformly brown above, rather paler below, short-haired, and usually with terminal white tip.

Habitat. Montane forest, shrubby paramo, and edge of timberline in dry forests of Rio Maranon Valley and mainly primary and secondary forests and disturbed areas at elevations of 2050-4000 m.

Food and Feeding. No information.

Breeding. No information.

Activity patterns. The Cajamarca Oldfield Mouse is nocturnal. The speciesis terrestrial and possibly arboreal.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Data Deficient on The IUCN Red List. Knowledge of natural history of the Cajamarca Oldfield Mouse is lacking, and it is not known to occur in any protected areas.

Bibliography. Cabrera (1961), Lee et al. (2011), Osgood (1914b), Pacheco (2003, 2015b), Pacheco & Vargas (2008f), Pacheco et al. (2009), Thomas (1900c), Voss (1991a, 2003).