Abrothrix olivaceus Waterhouse 1837

Wilson, Don E. & Reeder, DeeAnn, 2005, Order Rodentia - Family Cricetidae, Mammal Species of the World: a Taxonomic and Geographic Reference (3 rd Edition), Volume 2, Baltimore: The Johns Hopkins University Press, pp. 955-1189 : 1090

Abrothrix olivaceus Waterhouse 1837

Abrothrix olivaceus Waterhouse 1837 , Proc. Zool. Soc. Lond., 1837: 16.

Type Locality: Chile, Aconcagua Prov., Valparaíso.

Vernacular Names: Olive-colored Akodont.

Synonyms: Abrothrix atratus ( Philippi 1900) ; Abrothrix beatus Thomas 1919 ; Abrothrix brachiotis (Waterhouse 1837) ; Abrothrix brevicaudatus (Philippi 1872) ; Abrothrix canescens (Waterhouse 1837) ; Abrothrix chonoticus ( Philippi 1900) ; Abrothrix foncki ( Philippi 1900) ; Abrothrix germaini ( Philippi 1900) ; Abrothrix infans ( Philippi 1900) ; Abrothrix landbecki ( Philippi 1900) ; Abrothrix lepturus ( Philippi 1900) ; Abrothrix llanoi Pine 1976 ; Abrothrix longibarbus ( Philippi 1900) ; Abrothrix macronychos ( Philippi 1900) ; Abrothrix mansoensis (De Santis and Justo 1980) ; Abrothrix mochae ( Philippi 1900) ; Abrothrix nasica ( Philippi 1900) ; Abrothrix nemoralis ( Philippi 1900) ; Abrothrix pencanus ( Philippi 1900) ; Abrothrix psilurus ( Philippi 1900) ; Abrothrix renggeri ( Waterhouse 1839) ; Abrothrix ruficaudus ( Philippi 1900) ; Abrothrix senilis ( Philippi 1900) ; Abrothrix trichotis ( Philippi 1900) ; Abrothrix vinealis ( Philippi 1900) ; Abrothrix xanthopus ( Philippi 1900) ; Abrothrix xanthorhinus (Waterhouse 1837) .

Distribution: N Chile, south through C Chile and bordering area of westernmost Argentina, to Patagonian region of S Chile and Argentina, including Tierra del Fuego.

Conservation: IUCN – Lower Risk (lc) as Akodon olivaceus , Akodon mansoensis , and Akodon xanthorhinus .

Discussion: Systematists have either viewed olivaceus and xanthorhinus as distinct species, based on their apparent morphological and ecological separation in local settings ( Osgood, 1943; Patterson et al., 1984; Pearson, 1995); or treated olivaceus as a polytypic species, also embracing southern xanthorhinus , based on broader regional trends of morphological and morphometric variation ( Mann, 1978; Yañez et al., 1979). In an allozymic study drawing upon limited geographic sampling, Barrantes et al. (1993) depicted xanthorhinus as more differentiated from A. longipilis than is olivaceus and represented the three as species. Recently, detailed transects in two regions where Valdivian rainforest ( olivaceus morphotype) grades into Patagonian steppe ( xanthorhinus morphotype) have disclosed evidence of demic intergradation, results that strongly argue their synonymy ( Smith et al., 2001; Pearson and Smith, 1999). Smith et al. (2001) elaborated a biogeographic hypothesis to explain the morphological and ecological diversification within A. olivaceus during the late Pleistocene.

Type locality and karyotype of xanthorhinus discussed by Patterson et al. (1984), who judged the form infans Philippi (1900) , synonymized under Akodon xanthorhinus by Osgood (1943), as a nomen dubium and considered llanoi Pine (1976 b) as a subjective synonym of Akodon x. xanthorhinus . Also includes mansoensis , described as a species but whose distinctiveness was questioned by Reig (1987), Monjeau et al. (1994), and Pearson (1995); the form is morphologically and genetically inseparable from A. olivaceus proper ( Pearson and Smith, 1999). Pearson and Smith (1999) implicated hershkovitzi as yet another junior synonym of A. olivaceus . Although Smith et al. (2001) offered a trinomial arrangement for the samples they studied, the many synonymies recently enacted or suggested recommend a fresh evaluation of intraspecific variation to reinforce formal recognition of racial divisions. Attribution of Philippi's numerous epithets follows Osgood (1943). See Lozada et al. (1996, Mammalian Species, 540—in part, as Abrothrix xanthorhinus ) .