Almost one-quarter of living mammal species are bats -- members of the order Chiroptera. Bats play a variety of important ecological roles. Many bat species prey on nocturnal insects, while others are essential to the pollination of flowering plants. Increasing human impact on bat populations and species has serious implications for agriculture and insect pest management. Despite many previous studies, there is still little agreement among biologists concerning relationships among higher-level bat groups (e.g., genera and families). Without such knowledge, it is difficult to interpret the wide ranges of variation in wing architecture, sonar capabilities, and ecology seen in different bats. A clear understanding of bat diversity -- important for setting conservation priorities -- depends upon resolving the relationships (phylogeny) of bats. In this study, the problem of bat relationships will be addressed through a detailed analysis of the anatomy of the skeleton (excluding the cranium) and the muscles of a wide variety of bats. Recent bats will be studied using dried skeletons, muscle dissections, and cleared and stained specimens. Fossil bats will be studied by direct observation and x-ray analysis. The object of these studies will be to identify similarities and differences in anatomical structure that can be used to evaluate relationships. Data collected in this study will be employed in a variety of computer-assisted analyses designed to produce testable hypotheses of relationships within and among families of bats. The relationships of bats to other mammalian groups (such as Primates) will also be investigated. In conjunction with data from molecular studies and previous surveys of other anatomical systems, this study should provide a new framework for understanding the structural design, behavior, and ecology of bats.
