Mist netting bats at 11 sites in the vicinity of Akumal, Mexico between 7 and 19 January 1991 produced 363 bats representing 20 species. A comparison of captures revealed significant differences in species diversity (H s ) between disturbed and undisturbed sites (as reflected by deforestation). Species in the subfamily Phyllostominae (family Phyllostomidae) were captured significantly more often at forested than deforested sites and thus appeared to be useful indicators of habitat disruption. The low intensity echolocation calls of phyllostomid bats make it unfeasible to monitor their distribution and abundance with bat detectors