Brady, Beth

2 publications

Ramos, Eric Angel; Maust-Mol, Maria; Collom, Kristi A.; Brady, Beth; Gerstein, Edmund R.; Magnasco, Marcelo O.; Reiss, Diana (detail)
2020The Antillean manatee produces broadband vocalizations with ultrasonic frequencies.
Journal of the Acoustical Society of America 147(2): EL80-EL86. 1 tab. 3 figs. doi.org/10.1121/10.0000602 Feb. 5, 2020.
—ABSTRACT: Antillean manatees produce vocalizations reported to be important for communication, but their vocal behavior throughout their geographic range is poorly understood. A SoundTrap recorder (sample rates: 288/576?kHz) was deployed in Belize to record vocalizations of wild manatees in a seagrass channel and of a young rehabilitated and released manatee in a shallow lagoon. Spectral analysis revealed broadband vocalizations with frequencies up to 150?kHz and a high proportion of calls with ultrasonic components. Ultrasonic frequency components appear prevalent in their vocal repertoire and may be important to manatee communication.
Brady, Beth; Moore, Jon; Love, Kim (detail)
2021Behavior related vocalizations of the Florida manatee (Trichechus manatus latirostris).
Mar. Mamm. Sci. https://doi.org/10.1111/mms.12904 Publ. online Dec. 31, 2021.
—ABSTRACT: Florida manatees (Trichechus manatus) produce five broadly defined call types (squeaks, squeals, high squeaks, chirps, squeak-squeals) but their use in social and nonsocial settings is unclear. The goal of this study was to investigate whether call categories and structure of manatee vocalizations varied with behavior. Multiple hydrophones were used to record vocalizations in four different environments and broad behavioral states. Vocalizations recorded from resting, cavorting, stressed, or feeding wild animals were subjected to mixed linear effects models to test whether vocalizations produced varied with behavior and calf presence. Measures of duration, entropy, and frequency modulation were extracted from vocalizations to investigate if structural parameters differ among behaviors. Although all five call categories were recorded, results suggest manatees vocalize using primarily three call types and vary the structure of the call based on behavior. High squeaks were correlated with calf presence. High entropy squeals were proportionally higher during cavorting suggesting they may be related to a heightened state of arousal. Squeaks were the dominant call type produced and were longer in duration and higher in frequency modulation when animals were stressed. This research provides a foundation for comparative studies on vocal behavior for the Florida manatee as well as studies on related species.