657.

Large-eared Oldfield Mouse

Thomasomys macrotis

French: Thomasomys a grandes oreilles / German: GroRohr-Paramomaus / Spanish: Raton de erial de orejas grandes

Other common names: Large-eared Thomasomys

Taxonomy. Thomasomys macrotis Gardner & M. Romo, 1993, “Puerta del Monte, ca. 30 km [of] Los Alisos, ca. 3250 m [Parque Nacional Rio Abiseo], San Martin, Peru.” This species is monotypic.

Distribution. Known only from the type locality and vicinity in NC Peru.

Descriptive notes. Head-body 153— 168 mm, tail 193-219 mm, ear 28-33 mm, hindfoot 44-48 mm; weight 140-166 g. The Large-eared Oldfield Mouse is largebodied, big-eared, but relatively short-tailed species of Thomasomys, with soft, dense, and comparatively long dorsal fur. Dorsum is bone brown to sepia, finely streaked with pale brown imparting agouti pattern; paler brown tones coversides and flanks; venter, including inside oflegs,is pinkish cinnamon; and ventral and dorsal pelage not countershaded. Mystacial vibrissae are moderately long, extending slightly beyond posterior margin of pinnae when bent. Hindfoot is long and narrow, with metacarpal surface as dark as dorsum, but with paler claws and digital bristles; metacarpals of forefeet are dark, with paler toes, claws, and digital bristles. Tail is 126-143% of head-body length and uniformly dark brown except for terminal onethird to two-fifths where both scales and hairs are white. Hallux is moderately long, with claw not extending more than about one-half the length offirst phalanx of second digit.

Habitat. Upper montane elfin forest at elevations of 3250-3380 m. Large-eared Oldfield Mice were caught in a rocky area in grassland near a fragmented forest.

Food and Feeding. No information.

Breeding. The type series was collected in August and showed not signals of reproductive activity except by a male with scrotal testes 17 mm in diameter.

Activity patterns. No information.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Vulnerable on The IUCN Red List. The Largeeared Oldfield Mouse is known from a single location in an area that is currently experiencing human degradation.

Bibliography. Gardner & Romo (1993), Leo & Romo (1992), Pacheco (2003, 2015b), Pacheco & Vargas (2008d), Pacheco et al. (2009).