Can echolocation calls provide information about group identity in the little brown bat (Myotis lucifugus)?

We studied the potential for colony-specific echolocation calls at maternity colonies of little brown bats, Myotis lucifugus, in Chautauqua County, New York. By analyzing echolocation calls recorded from free-flying bats returning to their roosts before dawn and those of known individuals in a captive setting, we tested for structural differences in the echolocation calls among maternity colonies. There were significant differences in the structure of the echolocation calls among the maternity colonies in both data sets, but the nature of these differences may depend on the setting in which the echolocation calls were produced. The echolocation calls of volant juveniles differed from those of adult females. Colony-specific echolocation calls could facilitate group and site recognition in microchiropteran bats.