Humpback whales (Megaptera novaeangliae) are vocal baleen whales that exhibit complex social interactions across broad spatial and temporal scales. On low latitude breeding grounds, humpback whales produce complex and highly stereotyped “songs” as well as a range of “social sounds” associated with breeding behaviors. While on their Southeast Alaskan foraging grounds, humpback whales produce vocalizations during cooperative foraging events as well as a range of unclassified vocalizations for which the social context remains unknown. This study investigates the vocal repertoire of Southeast Alaskan humpback whales from a sample of 366 vocalizations collected over a three-month period on foraging grounds in Frederick Sound, Southeast Alaska. We used a two-part classification system, which included aural-spectrogram and statistical cluster analyses, to describe and classify vocalizations. Vocalizations were classified into 19 individual call types nested within four call classes. The vocal repertoire of Southeast Alaskan humpbacks shows moderate overlap with vocalizations recorded in Atlantic foraging grounds and along the Australian migratory corridor.
