749.

Pearson’s Chaco Mouse

Andalgalomys pearsoni

French: Phyllotis du Paraguay / German: Pearson-Chacomaus / Spanish: Raton del Chaco de Pearson

Other common names: Pearson's pericote

Taxonomy. Graomys pearsoni Myers, 1977, 410 km (by road) NW Villa Hayes, Boqueron, Paraguay.

Two subspecies are recognized.

Subspecies and Distribution.

A.p.pearsoniMyers,1977—ChacoofWParaguayandsupposedlyNWArgentina(SaltaProvince).

A. p. dorbignyi Olds, S. Anderson & Yates, 1987 — SE Bolivia (Santa Cruz Department).

Descriptive notes. Head-body 86-126 mm, tail 97-136 mm, ear 18-24 mm, hindfoot 22-27 mm; weight 45 g. Both species of Andalgalomys are moderately small phyllotines, with large ears and whitish subauricular spots and post-auricular patches. Females apparently have three pairs of mammae (recorded on one Olrog’s Chaco Mouse, A. olrogi). Dorsum of Pearson’s Chaco Mouse is brown, streaked with gray to pale reddish brown; venteris snow white; and small buffy to white spots occur below ears. Tail is ¢.100% of head-body length, bicolored (dorsal one-third brown, ventral two-thirds buffy), and sparsely haired, with no pencil. Diploid number varies from 2n = 76 in Bolivian populations to 2n = 78 in populations from Paraguay.

Habitat. Dry gasslands surrounded by thornscrub in Chaco biome.

Food and Feeding. Insect remains were found into the mouth of a trapped Pearson’s Chaco Mouse, but teeth morphology suggests a mostly herbivorous-granivorousdiet.

Breeding. Pearson’s Chaco Mouse apparently breeds in winter and spring (dry season); males with scrotal tested have been trapped in July and September.

Activity patterns. Pearson’s Chaco Mouse is nocturnal and terrestrial.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red List.

Bibliography. Braun (2015), Dunnum, Vargas, Bernal, Pardifnas & D’Elia (2016), Myers (1977), Olds et al. (1987), Teta, Jayat & Ortiz (2016), Williams & Mares (1978).