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Altiplano Chinchilla Mouse

Chinchillula sahamae

French: Souris-chinchilla de ‘Altiplano / German: Altiplano-Chinchillamaus / Spanish: Raton chinchilla de altiplano

Other common names: Achallo

Taxonomy. Chinchillula sahamae Thomas, 1898, “Esperanza, ... neighbourhood of Mount Sahama, Bolivia. ... altitude of of 4000 metres [= 1219 m] in the ‘Puna’ region.”

Chinchillula sahamae is the type species of the genus. Monotypic.

Distribution. Scattered localities in S Peru, W Bolivia, and N Chile.

Descriptive notes. Head-body 150-166 mm, tail 95-109 mm, ear 33-36 mm, hindfoot 31-33 mm; weight 73-134 g. Male Altiplano Chinchilla Mice seem to be slightly larger than females. It is a strikingly marked, medium-to-large, beautiful, and silken-haired Andean sigmodontine, with short and well-haired bicolored tail, with thin terminal pencil, and mid-dorsal brown stripe. Pelage is long, very dense, silky, and distinctly buffy to tawny, lined with black on back and white on venter. Hips and rump are white but are crossed by conspicuous black band. Ears are long, broad, and brown, with white preauricular and post-auricular tufts. Limbs and feet are white, and ungual tufts almost conceal claws. Plantar pads are smooth and bare and have large tubercles. Molars are noticeable by their prismatic appearance, being one of the more hypsodont living sigmodontine.

Habitat. Shrubland, Polylepis (Rosaceae) patches, and bunchgrass-dominated Andean Altiplano (high plateau), often associated with rocky outcrops or man-made stone walls at elevations of 3500-4800 m.

Food and Feeding. The Altiplano Chinchilla Mouse eats grass, herbs, and rarely seeds.

Breeding. Signs of reproductive activity of Altiplano Chinchilla Mice start in early October, including open vagina and prominent nipples of females and nearly spherical testes reaching ¢.6-7 mm of diameter in males. Growth patterns of captive individuals suggest exponential growth for the first eight weeks after birth, reaching an asymptote at c.15 days old.

Activity patterns. The Altiplano Chinchilla Mouse is nocturnal and terrestrial. Some climbing abilities have been reported for this rodent.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Altiplano Chinchilla Mouse has a wide distribution and presumably large overall population, occurs in protected areas,is tolerant of some habitat modification, and is unlikely declining fast enough to qualify forlisting in a threatened category. Although thought to be threatened or even at risk in Chile and Peru, possibly due to overexploitation for its colorful pelt, no studies have been conducted to assess local population status.

Bibliography. Aliaga-Rossel et al. (2009), Anderson (1997), Cofré & Marquet (1999), Dorst (1973b), Dunnum, Vargas, Bernal, Zeballos et al. (2008), Mann (1978), Pearson (1951a), Thomas (1898c), Salazar-Bravo (2015a), Yensen & Tarifa (2002), Zeballos & Carrera (2010), Zeballos etal. (2001).