title: Beaked whale and dolphin tracking using a multichannel autonomous acoustic recorder.
abstract: To track highly directional echolocation clicks from odontocetes, passive hydrophone arrays with small apertures can be used to receive the same high frequency click on each sensor. A four-hydrophone small-aperture array was coupled to an autonomous acoustic recorder and used for long-term tracking of high-frequency odontocete sounds. The instrument was deployed in the spring of 2009 offshore of southern California in a known beaked whale and dolphin habitat at about 1000 m depth. The array was configured as a tetrahedron with approximately 0.5 m sensor spacing. Time difference of arrival measurements between the six sensor-pairs were used to estimate three-dimensional bearings to sources. Both near-seafloor beaked whales and near-sea surface dolphins were tracked. The tracks observed using this technique provide swimming and diving behavioral information for free-ranging animals using a single instrument. Furthermore, animal detection ranges were derived, allowing for estimation of detection probability functions.
authors.affiliation: Scripps Institution of Oceanography, 9500 Gilman Drive, La Jolla, California 92093-0205, USA. swiggins@ucsd.edu
authors.forename: Sean M
authors.initials: SM
authors.lastname: Wiggins
authors.forename: Mark A
authors.initials: MA
authors.lastname: McDonald
authors.forename: John A
authors.initials: JA
authors.lastname: Hildebrand
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D000818:Animals; D003625:Data Collection; D004289:Dolphins / Q000502:physiology*; D004455:Echolocation / Q000502:physiology*; D004867:Equipment Design; D013018:Sound Spectrography; D013637:Tape Recording; D014828:Vocalization, Animal / Q000502:physiology*; D014907:Whales / Q000502:physiology*