Comparison of the wing morphology of Tadarida brasiliensis (Chiroptera : Molossidae) and Myotis chiloensis (Chiroptera : Vespertilionidae) as representatives of two flight patterns

Wing morphology is related by one hand to biomechanical properties and ener getics of flying, and on the other hand to ecological and behavioral aspect s of flying, such as flight pattern, foraging behavior, habitat selection a nd size of prey. In this work we compare the wing morphology of Tadarida br asiliensis (Molossidae) and Myotis chiloensis (Vespertilionidae), as repres entatives of two flight patterns, and looking for trade-offs between wing m orphology, ecology and behavior. Our results showed that T. brasiliensis is larger and with higher wing span than M. chiloensis, although the wing are a does not differ between these bats. The latter species showed a smaller v ariability in body mass and cortical area of humerus, probably related with mechanic and energetic constraints. Without size effect, there were differ ences in the external diameter and medullar diameter of humerus, but with a similar cortical area. The humerus of T. brasiliensis is a bone of similar length, wider and with smaller cortical thickness than in M. chiloensis, w hich is related to a higher resistance to bending and torsional forces. The wing shape found in each bat is in agree with the life mode: slow, short a nd manoeuvrable flight in wooded zones of M. chiloensis and fast and long d istance flight in open areas of T. brasiliensis.