AbstractHistiotus magellanicus (Philippi, 1866) is a vespertilionid bat called the southern big-eared brown bat. The dark color of the ears and the absence of a connecting band between the ears are the characters that clearly differentiate this species from all other species of Histiotus. It is a little-known species with a distribution restricted to the southern portions of Argentina and Chile. H. magellanicus is listed as “Least Concern” by the International Union for Conservation of Nature and Natural Resources.