No abstract

Determination of age of several species of vespertilionid bats by counting incremental lines in dentine, cementum, and peridontal bone is described. The technique was most effective for aging Eptesicus fuscus and Lasionycteris noctivagans and less so for Myotis lucifugus. Incremental lines in specimens of Lasiurus cinereus and Lasiurus borealis were clearly defined, while those in a Myotis californicus were not. Longevity of E. fuscus and longevity and apparent age structure of M. lucifugus agree with the findings of published banding studies.