SEARCH

SEARCH BY CITATION

Keywords:

  • species identification;
  • towed hydrophone array;
  • sonobuoy;
  • discriminant function analysis;
  • decision tree;
  • dolphin;
  • whistle;
  • acoustic;
  • Stenella longirostris;
  • Stenella attenuata;
  • Stenella coeruleoalba;
  • Delphinus delphis;
  • Delphinus capensis;
  • Tursiops truncatus;
  • Steno bredanensis;
  • Globicephala macrorhynchus;
  • Pseudorca crassidens

Abstract

Acoustic methods may improve the ability to identify cetacean species during shipboard surveys. Whistles were recorded from nine odontocete species in the eastern tropical Pacific to determine how reliably these vocalizations can be classified to species based on simple spectrographic measurements. Twelve variables were measured from each whistle (n = 908). Parametric multivariate discriminant function analysis (DFA) correctly classified 41.1% of whistles to species. Non-parametric classification and regression tree (CART) analysis resulted in 51.4% correct classification. Striped dolphin whistles were most difficult to classify. Whistles of bottlenose dolphins, false killer whales, and pilot whales were most distinctive. Correct classification scores may be improved by adding prior probabilities that reflect species distribution to classification models, by measuring alternative whistle variables, using alternative classification techniques, and by localizing vocalizing dolphins when collecting data for classification models.