Anders Galatius

Evolution of narrow band - high frequency hearing in odontocetes

Research output: Contribution to conferenceConference abstract for conferenceResearch

  • Lee A. Miller, Institute of Biology, University of Southern Denmark, Odense M, Denmark
  • Anders Galatius
  • Morten Tange Olsen, Statens Naturhistoriske Museum
  • ,
  • Rachel Ann Racicot, Yale University
  • ,
  • Mette Steeman, Museum Sønderjylland, Denmark
Whale biologists generally agree that predation by killer whales provided selection pressure for driving up the biosonar frequencies of some odontocetes. This made the signals of these species, like the harbor porpoise, less audible to their predator. But why should the acoustic signals of 13 to 15 known species in four families have peak frequencies between 120 kHz and 140 kHz? We propose and argue that at these frequencies an ambient noise minimum exists and has so over the past 10 million years or more. The spectral properties of the signals produced by smaller odontocetes, like the harbor porpoise, have thus been shaped by predation pressure from larger odontocetes, driving the frequency up, and limited by increasing ambient noise above about 140 kHz. The result is a high frequency, narrow band acoustic signal. To support the above conclusions we use palæontological, palæoclimatic, anatomical and phylogenetic data.
Original languageEnglish
Publication year2015
Publication statusPublished - 2015

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