Comparing call-based versus subunit-based methods for categorizing Norwegian killer whale, Orcinus orca, vocalizations
Shapiro, Ari D.
Tyack, Peter L.
MetadataShow full item record
Students of animal communication face significant challenges when deciding how to categorise calls into subunits, calls, and call series. Here, we use algorithms designed to parse human speech to test different approaches for categorising calls of killer whales. Killer whale vocalisations have traditionally been categorised by humans into discrete call types. These calls often contain internal spectral shifts, periods of silence, and synchronously produced low and high frequency components, suggesting that they may be composed of subunits. We describe and compare three different approaches for modelling Norwegian killer whale calls. The first method considered the whole call as the basic unit of analysis. Inspired by human speech processing techniques, the second and third methods represented the calls in terms of subunits. Subunits may provide a more parsimonious approach to modelling the vocal stream since (1) there were fewer subunits than call types; (2) nearly 75% of all call types shared at least one subunit. We show that contour traces from stereotyped Norwegian killer whale calls yielded similar automatic classification performance using either whole calls or subunits. We also demonstrate that subunits derived from Norwegian stereotyped calls were detected in some Norwegian variable (non-stereotyped) calls as well as the stereotyped calls of other killer whale populations. Further work is required to test whether killer whales use subunits to generate and categorize their vocal repertoire.
Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Animal Behaviour 81 (2011): 377-386, doi:10.1016/j.anbehav.2010.09.020.
Showing items related by title, author, creator and subject.
Mehta, Amee V.; Allen, Judith M.; Constantine, Rochelle; Garrigue, Claire; Jann, Beatrice; Jenner, Curt; Marx, Marilyn K.; Matkin, Craig O.; Mattila, David K.; Minton, Gianna; Mizroch, Sally A.; Olavarría, Carlos; Robbins, Jooke; Russell, Kirsty G.; Seton, Rosemary E.; Steiger, Gretchen H.; Víkingsson, Gísli A.; Wade, Paul R.; Witteveen, Briana H.; Clapham, Phillip J. (Inter-Research, 2007-10-25)Certain populations of killer whales Orcinus orca feed primarily or exclusively on marine mammals. However, whether or not baleen whales represent an important prey source for killer whales is debatable. A hypothesis by ...
Distinctions in sound patterns of calls by killer whales (Orcinus Orca) from analysis of computer sound features Watkins, William A.; Daher, Mary Ann; DiMarzio, Nancy A.; Reppucci, Gina (Woods Hole Oceanographic Institution, 1998-03)Calls of killer whales, Orcinus orca, were analyzed using computed sound features to classify sound patterns and identify call similarties. Calls were classified and separated according to the podfamily group within clans ...
Killer whales and marine mammal trends in the North Pacific : a re-examination of evidence for sequential megafauna collapse and the prey-switching hypothesis Wade, Paul R.; Burkanov, Vladimir N.; Dahlheim, Marilyn E.; Friday, Nancy A.; Fritz, Lowell W.; Loughlin, Thomas R.; Mizroch, Sally A.; Muto, Marcia M.; Rice, Dale W.; Barrett-Lennard, Lance G.; Black, Nancy A.; Burdin, Alexander M.; Calambokidis, John; Cerchio, Sal; Ford, John K. B.; Jacobsen, Jeff K.; Matkin, Craig O.; Matkin, Dena R.; Mehta, Amee V.; Small, Robert J.; Straley, Janice M.; McCluskey, Shannon M.; VanBlaricom, Glenn R. (Blackwell, 2007-10-26)Springer et al. (2003) contend that sequential declines occurred in North Pacific populations of harbor and fur seals, Steller sea lions, and sea otters. They hypothesize that these were due to increased predation by killer ...