Detecting killer whale whistles and squeals.

Abstract

An algorithm has been devised for detection of tonal sounds, including whistles of odontocetes and moans and other sounds of baleen whales [Mellinger et al., J. Acoust. Soc. Am. (in press)]. Here we test for detection of whistles, squeals, burst pulses, and other tonal and tonal-like sounds of killer whales (Orcinus orca). The method is controlled using a large number of parameters, and these parameters must be chosen to as to detect killer whale sounds and not sounds of other cetaceans. The cosmopolitan range of killer whales means that they are sympatric with nearly every other species of cetacean, and thus detection must handle these other species. Here detectors are configured to detect orca tonal sounds and to avoid detecting sounds of sympatric cetaceans, such as pilot whales (Globicephala spp.), that produce whistles and other tonal vocalizations that overlap the frequency range of killer whales.