748.

Delicate Salt Flat Mouse

Salinomys delicatus

French: Phyllotis des Salinas / German: Zierliche Salzmaus / Spanish: Raton de salinas

Other common names: Delicate Salinomys

Taxonomy. Salinomys delicatus Braun & Mares, 1995, “Province of San Luis, Departamento de Ayacucho, ca. 23 km N Route 20, Pampa de Las Salinas, cerca La Botija, at 1300 feet elevation [= 396 m].”

Salinomys delicatus is the type species of the genus. Alpha-taxonomy is poorly explored; scattered occurrence and restriction to isolated salt basins invite to further studies. Monotypic.

Distribution. WC Argentina (Catamarca, La Rioja, San Juan, Mendoza, and San Luis provinces).

Descriptive notes. Head-body 62-81 mm, tail 93-123 mm, ear 16-21 mm, hindfoot 19-23 mm; weight 9-14 g (all values combining measurements recorded for adult males and females). Apparently, females are larger than males in body size. The Delicate Salt Flat Mouse has proportionately large ears, whitish post-auricular and supraorbital patches, soft grayish olive fur, white venter, and tufted bicolored tail that exceeds head-body length. Hindfeet are long, with naked plantar surfaces. Diploid number is sexually dimorphic, 2n = 18 for females and 2n = 19 for males, and both sexes have FN = 32.

Habitat. Edges of salt flats in Monte Desert biome at elevations of 400-600 m. The Delicate Salt Flat Mouse has been collected in xeric and semiarid habitats on edges of salt flats and in small patches of mesquite ( Prosopis, Fabaceae).

Food and Feeding. The Delicate Salt Flat Mouse is omnivorous and eats similar proportions of seeds, arthropods, and halophytic plants ( Allenrolfea vaginata, Atriplex lampa, and Suaeda divaricata, all Amaranthaceae).

Breeding. Reproductive activity of Delicate Salt Flat Mice apparently is highest in late summer and early autumn, although a pregnant female was recorded in spring. Litters have 2-6 young. Sex ratio and pattern of sexual dimorphism are strongly female biased.

Activity patterns. The Delicate Salt Flat Mouse is nocturnal, terrestrial, and potentially scansorial.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Data Deficient on The IUCN Red List. The Delicate Salt Flat Mouse should probably be reclassified as Least Concern because it occurs in a wide geographical area, despite few records at hand, and there are no major conservation threats.

Bibliography. Braun & Mares (1995), Jayat & Pardifas (2008c), Lanzone & Braun (2015), Lanzone, Ojeda et al. (2005), Lanzone, Rodriguez et al. (2011), Ojeda et al. (2001), Rodriguez etal. (2012).