[1] Univ St Andrews, Scottish Oceans Inst, St Andrews KY16 LB8, Scotland
[2] Cornell Univ, Bioacoust Res Program, Ithaca, NY 14850 USA
[3] Aarhus Univ, Dept Biol, Sect Zoophysiol, Aarhus, Midtjylland, Denmark
[4] Cornell Univ, Dept Neurobiol & Behav, Ithaca, NY USA
[5] Dalhousie Univ, Dept Biol, Halifax, NS, Canada
[6] Texas A&M Univ, Dept Marine Biol, Galveston, TX 77553 USA