title: High-frequency modulated signals of killer whales (Orcinus orca) in the North Pacific.
abstract: Killer whales in the North Pacific, similar to Atlantic populations, produce high-frequency modulated signals, based on acoustic recordings from ship-based hydrophone arrays and autonomous recorders at multiple locations. The median peak frequency of these signals ranged from 19.6-36.1 kHz and median duration ranged from 50-163 ms. Source levels were 185-193 dB peak-to-peak re: 1 μPa at 1 m. These uniform, repetitive, down-swept signals are similar to bat echolocation signals and possibly could have echolocation functionality. A large geographic range of occurrence suggests that different killer whale ecotypes may utilize these signals.
authors.affiliation: Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0205, USA. asimonis@ucsd.edu
authors.forename: Anne E
authors.initials: AE
authors.lastname: Simonis
authors.forename: Simone
authors.initials: S
authors.lastname: Baumann-Pickering
authors.forename: Erin
authors.initials: E
authors.lastname: Oleson
authors.forename: Mariana L
authors.initials: ML
authors.lastname: Melcón
authors.forename: Martin
authors.initials: M
authors.lastname: Gassmann
authors.forename: Sean M
authors.initials: SM
authors.lastname: Wiggins
authors.forename: John A
authors.initials: JA
authors.lastname: Hildebrand
mesh_terms: D000818:Animals; D004455:Echolocation / Q000502:physiology; D013018:Sound Spectrography; D014828:Vocalization, Animal / Q000502:physiology*; D050685:Whale, Killer / Q000502:physiology*