Systematics of mice of the subgenus Akodon (Rodentia, Cricetidae) in southern South America, with the description of a new species

Abstract

Two species of yellow-nosed mice (genus Akodon) occur in the forests and steppes of southern South America, but only one of these is currently named. A. xanthorhinus applies to the smaller, shorter-tailed species found over much of southern Chile and Argentina. A larger, longer-tailed form inhabits islands to the south; this form is described as new. Geographic variation throughout the range of A. xanthorhinus is examined to assess the taxonomic position of the new form. Clinal variation does not account for the substantial difference of the new form: specimens of A. xanthorhinus from geographically intermediate localities on Isla Grande de Tierra del Fuego are no more similar to the new form than are specimens from the mainland. The new form is, therefore, best considered a distinct species, A. hershkovitzi sp. nov.