Gulf of Alaska | Mammals DOCTORATE POSTER PRESENTATION Vocal repertoire of the Cook Inlet beluga whale ( Delphinapterus leucas ) population Presenter: Arial Brewer , arialb@uw.edu, University of Washington Manuel Castellote , manuel.castellote@noaa.gov, Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA Understanding vocal behavior is crucial in the study of endangered species who rely heavily on acoustic communication for survival. It can reveal critical information communicated among conspecifics regarding predator avoidance, foraging locations, mate selection, and group cohesion, and aide managers in species conservation. Vocal repertoire analysis can provide a baseline for studies on conspecific communication, vocal learning in young animals, and population structure. Beluga whales ( Delphinapterus leucas ) are a highly gregarious and vocal species of cetacean and have a circumpolar distribution. Of the five populations in Alaska, the Cook Inlet population is the most endangered with a population estimate of 279 individuals. Among the threats listed as high concern, impacts from anthropogenic noise have the potential to negatively impact how this population communicates to conspecifics. We measured the acoustic characteristics of Cook Inlet beluga whale vocalizations (n=1,633) from two critical habitat locations (Trading Bay and Susitna River Delta) across multiple seasons. Following previous beluga repertoire studies, we classified vocalizations into three categories: whistles (n=1,264, 77.4%, 25 types), pulsed calls (n=354, 21.68%, 15 types) and combined calls (15, 0.92%, 7 types). We then compared the Cook Inlet beluga vocal repertoire with published repertoires of other beluga populations to qualitatively describe geographic variation in call use. Since anthropogenic noise is considered a threat to this population, we also investigated the potential masking level that commercial ship noise may have on important vocalizations. Understanding how and which vocalizations may be masked could provide important information supporting the management and conservation of this endangered population. Amy Van Cise , avancise@uw.edu, University of Washington Andrew Berdahl , berdahl@uw.edu, University of Washington Tom Gage , tom.gage@alaska.gov, Alaska Department of Fish and Game
Alaska Marine Science Symposium 2023 252
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