title: Repeated call types in Hawaiian melon-headed whales (Peponocephala electra).
abstract: Melon-headed whales are pantropical odontocetes that are often found near oceanic islands. While considered sound-sensitive, their bioacoustic characteristics are relatively poorly studied. The goal of this study was to characterize the vocal repertoire of melon-headed whales to determine whether they produce repeated calls that could assist in recognition of conspecifics. The first tag-based acoustic recordings of three melon-headed whales were analyzed. Tag records were visually and aurally inspected and all calls were individually extracted. Non-overlapping calls with sufficient signal-to-noise were then parameterized and visually grouped into categories of repeated call types. Thirty-six call categories emerged. Categories differed significantly in duration, peak and centroid frequency, and -3 dB bandwidth. Calls of a given type were more likely to follow each other than expected. These data suggest that repeated calls may function in individual, subgroup, or group recognition. Repeated call production could also serve to enhance signal detection in large groups with many individuals producing simultaneous calls. Results suggest that caution should be used in developing automatic classification algorithms for this species based on small sample sizes, as they may be dominated by repeated calls from a few individuals, and thus not representative of species- or population-specific acoustic parameters.
authors.affiliation: Biology Department, Woods Hole Oceanographic Institution, MS#50, 266 Woods Hole Road, Woods Hole, Massachusetts 02543.
authors.forename: Maxwell B
authors.initials: MB
authors.lastname: Kaplan
authors.affiliation: Biology Department, Woods Hole Oceanographic Institution, MS#50, 266 Woods Hole Road, Woods Hole, Massachusetts 02543.
authors.forename: T
authors.initials: T
authors.lastname: Aran Mooney
authors.affiliation: Biology Department, Woods Hole Oceanographic Institution, MS#50, 266 Woods Hole Road, Woods Hole, Massachusetts 02543.
authors.forename: Laela S
authors.initials: LS
authors.lastname: Sayigh
authors.affiliation: Cascadia Research Collective, 218 1/2W, 4th Avenue, Olympia, Washington 98501.
authors.forename: Robin W
authors.initials: RW
authors.lastname: Baird
mesh_terms: D000162:Acoustics; D000465:Algorithms; D000818:Animals; D001307:Auditory Perception; D004289:Dolphins / Q000145:classification / Q000502:physiology* / Q000523:psychology; D010363:Pattern Recognition, Automated; D012815:Signal Processing, Computer-Assisted; D012919:Social Behavior; D013018:Sound Spectrography; D013045:Species Specificity; D013997:Time Factors; D014828:Vocalization, Animal / Q000145:classification