title: Quantitative analysis of the acoustic repertoire of southern right whales in New Zealand.
abstract: Quantitatively describing the acoustic repertoire of a species is important for establishing effective passive acoustic monitoring programs and developing automated call detectors. This process is particularly important when the study site is remote and visual surveys are not cost effective. Little is known about the vocal behavior of southern right whales (Eubalaena australis) in New Zealand. The aim of this study was to describe and quantify their entire vocal repertoire on calving grounds in the sub-Antarctic Auckland Islands. Over three austral winters (2010-2012), 4349 calls were recorded, measured, and classified into 10 call types. The most frequently observed types were pulsive, upcall, and tonal low vocalizations. A long tonal low call (≤15.5 s duration) and a very high call (peak frequency ∼750 Hz) were described for the first time. Random Forest multivariate analysis of 28 measured variables was used to classify calls with a high degree of accuracy (82%). The most important variables for classification were maximum ceiling frequency, number of inflection points, duration, and the difference between the start and end frequency. This classification system proved to be a repeatable, fast, and objective method for categorising right whale calls and shows promise for other vocal taxa.
authors.affiliation: Department of Marine Science, University of Otago, 310 Castle Street, Dunedin 9016, New Zealand.
authors.forename: Trudi A
authors.initials: TA
authors.lastname: Webster
authors.affiliation: Department of Marine Science, University of Otago, 310 Castle Street, Dunedin 9016, New Zealand.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Dawson
authors.affiliation: Department of Marine Science, University of Otago, 310 Castle Street, Dunedin 9016, New Zealand.
authors.forename: William J
authors.initials: WJ
authors.lastname: Rayment
authors.affiliation: Department of Biology, Syracuse University, Syracuse, New York 13244, USA.
authors.forename: Susan E
authors.initials: SE
authors.lastname: Parks
authors.affiliation: Protected Species Branch, National Oceanic and Atmospheric Administration/Northeast Fisheries Science Center, 166 Water Street, Woods Hole, Massachusetts 02543, USA.
authors.forename: Sofie M
authors.initials: SM
authors.lastname: Van Parijs
mesh_terms: D000162:Acoustics; D000818:Animals; D009520:New Zealand; D012621:Seasons; D013018:Sound Spectrography; D013045:Species Specificity; D014828:Vocalization, Animal / Q000502:physiology*; D014907:Whales / Q000502:physiology*