SUMMARY
Long-finned pilot whales are highly social odontocetes found in temperate and subpolar regions. This species is particularly known for its interaction with fisheries as well as its mass strandings. Recent tagging work has provided some information about pilot whales in the wild but, even though they have been successfully kept in captivity, little is known about their sensory capabilities. This study investigates the hearing abilities of a rehabilitated 2 year old male long-finned pilot whale. A complete audiogram was collected using auditory evoked potential techniques that included measurements of nine frequencies from 4 to 100 kHz presented as sinusoidally amplitude-modulated tones. The results indicated that the region of best hearing was between 11.2 and 50 kHz and the subject had relatively poor high frequency hearing compared with other odontocete species. This study emphasizes the importance of collecting basic hearing measurements from new species, understanding diagnostic life histories as well as continuously increasing the sample size of audiometry measurements within and between odontocete species as animals become available.
FOOTNOTES
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This research project was supported by the Office of Naval Research (Grant NOO14-08-1-1160 to P.E.N.) for which the authors thank Jim Eckman and Neil Abercrombie. We are also very grateful for the appreciation and dedication of all the Lisbon Zoo marine mammal trainers and staff, particularly Valter Elias and Maria Manuel Oliveira for dedicating so much time to this study. The authors would like to acknowledge the assistance of ICNB. A special thank you goes to Joana Castro and her family for their hospitality. The authors also thank all the members of the Marine Mammal Research Program, Alexander Supin, T. Aran Mooney and Whitlow Au for their continuous assistance. This is contribution no. 1396 from the Hawaii Institute of Marine Biology and SOEST contribution no. 7987.
LIST OF ABBREVIATIONS
- ABR
- auditory brainstem response
- AEP
- auditory evoked potentials
- EFR
- envelope following response
- FFT
- fast Fourier transform
- r.m.s.
- root mean square
- SAM
- sinusoidally amplitude modulated
- SPL
- sound pressure level
- © 2010.