687.

Hairy Soft-haired Mouse

Abrothrix hirta

French: Abrothrix velu / German: Haarige Andenfeldmaus / Spanish: Ratén de pelaje suave peludo

Other common names: Hairy Soft-haired Akodont

Taxonomy. Acodon hirtus Thomas, 1895, “Fort San Rafael, Mendoza,” Argentina. Questioned by O. P. Pearson and H. A. Lagiglia in 1992 and changed to probably near Peteroa Volcano, on the Argentinean—Chilean border.

Abrothrix hirta is in the subgenus Abrothrix . The type locality has been suggested to be near Peteroa Volcano on the Argentinean—Chilean border, but a formal restriction is pending. A. hirta was recently removed from the traditional concept of A. longipilis . Therefore, most literature referred to the latter and as coming from Andean or southern ranges actually belonged to hirta . Numerous nominal forms have been used as subspecies of what is now called A. hirta . Concordance among different sets of evidence is weak to support a rationale trinomial classification. A comprehensive and integrative revision, including both Argentinean and Chilean populations, is needed. Monotypic.

Distribution. SC Chile and WC Argentina S to Tierra del Fuego.

Descriptive notes. Head—body 100 mm, tail 77 mm, ear 15 mm, hindfoot 25 mm, and weight 23 g (Neuquén Province); Head—body 100 mm, tail 76 mm, ear 15 mm, hindfoot 24 mm, and weight 20 g (Chubut Province); Head—body 103 mm, tail 73 mm, ear 15 mm, hindfoot 24 mm, and weight 22 g (Santa Cruz Province); mean values for large samples of adult males and females. See general characters of the genus under the Long-haired Soft-haired Mouse (A. longipilis) account. The Hairy Soft-haired Mouse is medium-sized and robust but smaller than the Long-haired Soft-haired Mouse;tail is bicolored; and pelage has long guard hairs. Color and size vary greatly geographically, but most populations retain reddish brown markings on back, bordered by more uniformly grayish flanks and venter. Argentinean steppe populations are usually smaller and light gray, with central upperparts slightly tinged with brownish and underparts and feet white. Forest Chilean populations are similar to the LLong-haired Soft-haired Mouse but smaller with less uniform color, more grayish sides that contrast more with back, paler underparts, and more frequently bicolored tail.

Habitat. Andean dense forests of Nothofagus (Nothofagaceae) to foreststeppe ecotones, shrublands, dense grassy steppes, and rocky exposures associated with moderate vegetation from sea level to elevations of ¢.3500 m. The Hairy Soft-haired Mouse prefers wet habitats with moderate to dense plant cover, deeply penetrating semiarid and cool parts of Patagonian steppe or basaltic tablelands and volcanic systems with large rocky areas.

Food and Feeding. In Argentina and Chile, Hairy Soft-haired Mice eat berries, seeds, fern spores, insects, fungi, worms, and slugs.

Breeding. From detailed studies in north-western Patagonia, Argentina, male Hairy Softhaired Mice were equal in length but 8% heavier than females, and sexually active males were longer and heavier than inexperienced males. Most females underwent several infertile ovulation cycles before becoming pregnant, shedding 4-7 ova and giving birth to litters averaging 3-8 young. By late October, most overwintering males were in breeding condition, and by November—-December, essentially all adult males were breeding. Pregnant and lactating females were caught in spring and summer (late October to February), and reproduction ceased before April. Embryo counts averaged 3-8 (range 2-5) in Rio Negro Province, Argentina, and 3-7 (range 2-5) in Malleco, Chile.

Activity patterns. The Hairy Soft-haired Mouse is mostly nocturnal but also active in morning and afternoon. It is terrestrial and can burrow and climb trees.

Movements, Home range and Social organization. High numbers of old individuals suggested that populations contained significant numbers of individuals that survived two winters. Population peaks occurred at end of summer and beginning of autumn. Lineal movements at Malleco were in areas no greater than 40-241 m®. Densities in the Nothofagus forest of Rio Negro, were 0-4—4-8 ind/ha in spring and 2-8-10-8 ind/ha in autumn.

Status and Conservation. Not assessed on The [UCN Red List as a separate species from A. longipilis . Based on detailed studies, it is clear that the Hairy Soft-haired Mouse deserves classification as Least Concern.

Bibliography. Chebez et al. (2014), Contreras & Rosi (1981a), Gallardo et al. (1988), Guthmann et al. (1997), Justo et al. (1987), Kelt (1994, 1996), Kelt et al. (1994), Lessa et al. (2010), Mann (1978), Meserve, Kelt & Martinez (1991), Meserve, Lang, Murua et al. (1991), Meserve, Lang & Patterson (1988), Monjeau (1989), Monjeau, Birney et al. (1998), Monjeau, Bonino & Saba (1994), Monjeau, Sikes et al. (1997), Osgood (1943a), Palma, Cancino & Rodriguez-Serrano (2010), Pardinas, Teta, Cirignoli & Podesta (2003), Pardinas, Teta, D'Elia & Lessa (2011), Patterson, Meserve & Lang (1989, 1990), Patterson, Smith & Teta (2015), Pearson (1983, 1992, 1995, 2002), Pearson & Lagiglia (1992), Pearson & Pearson (1982), Perez et al. (1989), Polop et al. (2015), Reig (1987), Reise & Venegas (1987), Sierra-Cisternas (2010), Silva (2005), Teta (2013), Teta & Pardinas (2014), Thomas (1895, 1927¢), Waterhouse (1837), Yanez et al. (1978).