Do you hear what I see? Vocalization relative to visual detection rates of Hawaiian hoary bats (Lasiurus cinereus semotus).

摘要: Bats vocalize during flight as part of the sensory modality called echolocation, but very little is known about whether flying bats consistently call. Occasional vocal silence when approach prey or conspecifics has been documented for relatively few species and situations. alone in clutter-free airspace are not to forgo vocalization, yet prior observations suggested possible silent behavior certain, unexpected Determining when, why, where occurs will help evaluate major assumptions a primary monitoring method used ecological research, management, conservation. In this study, we recorded activity Hawaiian hoary (Lasiurus cinereus semotus) under seminatural conditions using both thermal video cameras acoustic detectors. Simultaneous audio recordings from 20 nights observation at 10 sites were analyzed correspondence between detection methods, with focus on three distance categories which accompanying vocalizations detected. Comparison detections revealed that high proportion "seen" simultaneously "heard." On average, only one visual within night had an call detection, varied greatly among nights. curved paths individuals nearer more likely be detected by methods. Feeding social calls detected, no clear pattern emerged small number involving closely interacting bats. These results may indicate often do always way detectable common sampling Possible reasons low range methodological biological include biases associated propagation sound, cryptic foraging strategies, conspecific presence. Silent prevalent echolocating than previously appreciated, profound implications deserves further characterization study.