Although bats are well known for their use of ultrasound for echolocation, there is limited evidence for its use in a social context. We tested whether ultrasonic vocalizations in bats were contextually (roosting or flying) sexually dimorphic. During the reproductive season, we recorded ultrasonic signals of captive adult male and female big brown bats while the bats were flying on tether lines in the field, and compared these signals to ultrasonic vocalizations made while roosting in an anechoic chamber. Principal component analysis reduced 7 ultrasonic call descriptors to 2 components that related to frequency (PC1) and time or shape (PC2). While bats were roosting, ultrasonic call components related to time or shape and frequency were both sexually dimorphic, being increased in males in each instance. However, when bats were recorded while flying, these same call components were no longer sexually dimorphic. This finding suggests that bats are changing their ultrasonic calls in relation to functional context, making them monomorphic and utilitarian for activities such as foraging and navigation, but dimorphic in a situation when mating activity is likely.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.