(Uploaded by Plazi for the Bat Literature Project) The ecomorphology of 10 insectivorous bat species at three study zones in western Madagascar was examined using 567 specimens and based on 6 external, 11 cranial, 12 dental, and 11 wing measurements. The three study sites are located along a cline representing 11.61 of latitude. The southern most site has notable differences in vegetational and climatic regimes than the two more northern sites. Principal component analyses were conducted for each of the four datasets to examine the morphological space occupied by each species at the three sites. Most taxa showed clear intra-site separation and little inter-site variation. The exceptions included extensive morphological overlap in two taxa of Triaenops (cranial, dental, and wing), that have allopatric distributions, and between the sympatric Miniopterus manavi and Myotis goudoti (external, cranial, and dental). In the latter case, there was distinct separation in wing shape between these two taxa, which would allow them to exploit local habitats and prey in different manners. The only species that showed considerable inter-site variation was Hipposideros commersoni, which is sexually dimorphic, with individuals from the south being smaller than those in the north.