Quantitative analysis of the acoustic repertoire of southern right whales in New Zealand

Researchers have identified and quantified the full acoustic repertoire of southern right whales (Eubalaena australis) in New Zealand, revealing 10 distinct call types on their calving grounds in the sub-Antarctic Auckland Islands. Among these, pulsive, upcall, and tonal low vocalizations were most frequent, while a long tonal low call (≤15.5 s duration) and a very high call (peak frequency ∼750 Hz) were documented for the first time. Using Random Forest multivariate analysis on 28 measured variables, the study achieved an 82% accuracy in classifying calls, with maximum ceiling frequency, inflection points, duration, and start-end frequency differences proving most critical. This method offers a repeatable, fast, and objective approach to categorizing right whale calls, with potential applications for passive acoustic monitoring and automated call detection in remote or visually challenging environments.

Webster, T. A., Dawson, S. M., Rayment, W. J., Parks, S. E., & Van Parijs, S. M. (2016). Quantitative analysis of the acoustic repertoire of southern right whales in New Zealand. The Journal of the Acoustical Society of America, 140(1), 322–333. https://doi.org/10.1121/1.4955066