title: Temporal separation of two fin whale call types across the eastern North Pacific.
abstract: Fin whales (Balaenoptera physalus) produce a variety of low-frequency, short-duration, frequency-modulated calls. The differences in temporal patterns between two fin whale call types are described from long-term passive acoustic data collected intermittently between 2005 and 2011 at three locations across the eastern North Pacific: the Bering Sea, off Southern California, and in Canal de Ballenas in the northern Gulf of California. Fin whale calls were detected at all sites year-round, during all periods with recordings. At all three locations, 40-Hz calls peaked in June, preceding a peak in 20-Hz calls by 3-5 months. Monitoring both call types may provide a more accurate insight into the seasonal presence of fin whales across the eastern North Pacific than can be obtained from a single call type. The 40-Hz call may be associated with a foraging function, and temporal separation between 40- and 20-Hz calls may indicate the separation between predominately feeding behavior and other social interactions.
authors.affiliation: Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0205 USA.
authors.forename: Ana
authors.initials: A
authors.lastname: Sirović
authors.affiliation: Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0205 USA.
authors.forename: Lauren N
authors.initials: LN
authors.lastname: Williams
authors.affiliation: Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0205 USA.
authors.forename: Sara M
authors.initials: SM
authors.lastname: Kerosky
authors.affiliation: Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0205 USA.
authors.forename: Sean M
authors.initials: SM
authors.lastname: Wiggins
authors.affiliation: Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0205 USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Hildebrand