Beaked whale anatomy, field studies and habitat modeling

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Authors
Hildebrand, John
Subjects
Beaked whales
Baleen whales
Advisors
Date of Issue
2007
Date
2007
Publisher
Monterey, California. Naval Postgraduate School
Language
Abstract
Results of field studies of beaked whales in the Gulf of California for December 2004-December 2006 are described. The goal is to determine the range of sound produced by beaked whales and to investigate beaked whale behavior and habitat. A minimum of 17 cetacean species (12 toothed and 5 baleen whales) were observed in 147 sightings. The proportion of sighted toothed whales and baleen whales was 67% and 32%, respectively. A comprehensive formulation for finite element modeling of biological tissues was developed. The mesh is voxel-based, and is generated automatically from CT scans. CT data from live, frozen, and thawed specimens of Tursiops truncatus showed similar results in tissues and organs for the following quantities: geometry, absolute density, and sound velocity. Simulated sound sources placed inside and outside of modeled adult male Cuvier's beaked whale (Ziphius cavirostris) revealed pathways for acoustic propagation into and out of the head. The simulations indicated a new gular pathway for sound reception. Propagated sound pressure waves enter the head from below and between the lower jaws, continuing toward the bony ear complexes through the internal mandibular fat bodies.
Type
Technical Report
Description
Series/Report No
Department
Oceanography
Organization
Identifiers
NPS Report Number
NPS-OC-07-009
Sponsors
Funder
N00244-06-C-0030.
Format
v, 32 p.: ill. (chiefly col.) 28 cm.
Citation
Distribution Statement
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.