Morphofunctional and geographic segregation among species of lasiurine bats (Chiroptera: Vespertilionidae) from the South American Southern Cone

Abstract

Four morphologically similar species of insectivorous bats in the genus Lasiurus (Chiroptera: Vespertilionidae) regularly occur in the American Southern Cone. Three of them (Lasiurus cinereus, L. blossevillii and L. ega) are sympatric over many regions, whereas the remaining species (L. varius, closely related to L. blossevillii) is allopatric, occurring in the Patagonian Temperate Rainforest. A multivariate analysis of 14 craniodental variables for 99 specimens from the four species confirmed size separating two small species from two large ones, and revealed morphofunctional aspects of mastication segregating the two large species on the basis of differences in temporal muscle function (coronoid process height and length of rostrum). We predict ecological (trophic) differences among these lasiurines consistent with their segregation in the morphofunctional space and in combination with the sympatric vs. allopatric condition of species pairs or triads.