Characterizing the acoustic behavior of free-ranging Risso’s dolphin (Grampus griseus) in Monterey Bay, California
Risso’s dolphin (Grampus griseus) are a common, highly vocal odontocete species found in Monterey Bay, California that is relatively understudied acoustically. G. griseus produce unique vocal repertoires that include whistles and whistle+burst pulse vocalizations. This study seeks to characterize the acoustic behavior of Risso’s dolphins in Monterey Bay in order to compile a vocal catalog of this population’s repertoire. Omni-directional hydrophone deployments will be used to obtain recordings that will be analyzed using spectral analysis. Specific objectives of this study include (1) Delineate whistle and whistle+burst pulse combination types (2) Determine if acoustic behavior is characteristic of various behavioral states and (3) Determine group size and composition effects on vocalization rate.
This summer, Brijonnay Madrigal will be collecting acoustic and behavioral data as well as photos for photo ID of individuals in Monterey Bay.