665.

Ladew’s Oldfield Mouse

Thomasomys ladewi

French: Thomasomys de Ladew / German: Ladew-Paramomaus / Spanish: Ratén de erial de Ladew

Other common names: Ladew’s Thomasomys

Taxonomy. 7 Thomasomys ladewi Anthony, 1926, “Rio Aceramarca, northeast of La Paz, Bolivia, altitude 10,800 feet [= 3292 ml.” This species is monotypic.

Distribution. Restricted region in La Paz Department, NW Bolivia.

Descriptive notes. Head-body 120-138 mm, tail 158 mm, ear 20-23 mm, hindfoot 28-33 mm; weight 42-64 g. Fur of Ladew’s Oldfield Mouse is soft, lax, and long. Dorsal and ventral pelage is plumbeous butis tipped sooty black, fuscous, and brown on back; cheeks, sides, and lower rump are darker than mid-back; underparts are pale smoke gray to drab gray; pectoral area is darker than rest of underparts; and hands,feet, and tail (above and below) are grayish brown. Mystacial vibrissae are moderately long, extending slightly past posterior margins of pinnae when bent. Hallux is moderately long, with claw not extending more than about one-halfthe length offirst phalanx of second digit. Tail is longer than head-body length (107-132%), with very dispersed hair, and terminates in white tip.

Habitat. Rocky and wooded hillsides in montane forests at elevations of 2360-3300 m.

Food and Feeding. No information.

Breeding. No information.

Activity patterns. No information.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Ladew’s Oldfield Mouse is widely distributed, presumably has a large overall population, and is unlikely to be declining enough to be listed in a threatened category.

Bibliography. Anderson (1997), Anthony (1926a), Eisenberg & Redford (1999), Pacheco (2003, 2015b), Pacheco et al. (2009).