Transmission beam pattern and dynamics of a spinner dolphin (Stenella longirostris)
| Autor: | Lemnuel V. Aragones, Aude F. Pacini, Leo J. A. Suarez, Paul E. Nachtigall, Adam B. Smith, Gail E. Laule, Carlo Magno |
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| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
Sound Spectrography 010504 meteorology & atmospheric sciences Acoustics and Ultrasonics Acoustics Dolphins 01 natural sciences Directivity Standard deviation Arts and Humanities (miscellaneous) Hearing Stenella biology.animal Animals Ultrasonics Underwater 0105 earth and related environmental sciences Physics biology 010604 marine biology & hydrobiology Transmission (telecommunications) Stenella longirostris Echolocation Ultrasonic sensor Vocalization Animal Beam (structure) |
| Zdroj: | The Journal of the Acoustical Society of America. 145(6) |
| ISSN: | 1520-8524 |
| Popis: | Toothed whales possess a sophisticated biosonar system by which ultrasonic clicks are projected in a highly directional transmission beam. Beam directivity is an important biosonar characteristic that reduces acoustic clutter and increases the acoustic detection range. This study measured click characteristics and the transmission beam pattern from a small odontocete, the spinner dolphin (Stenella longirostis). A formerly stranded individual was rehabilitated and trained to station underwater in front of a 16-element hydrophone array. On-axis clicks showed a mean duration of 20.1 μs, with mean peak and centroid frequencies of 58 and 64 kHz [standard deviation (s.d.) ±30 and ±12 kHz], respectively. Clicks were projected in an oval, vertically compressed beam, with mean vertical and horizontal beamwidths of 14.5° (s.d. ± 3.9) and 16.3° (s.d. ± 4.6), respectively. Directivity indices ranged from 14.9 to 27.4 dB, with a mean of 21.7 dB, although this likely represents a broader beam than what is normally produced by wild individuals. A click subset with characteristics more similar to those described for wild individuals exhibited a mean directivity index of 23.3 dB. Although one of the broadest transmission beams described for a dolphin, it is similar to other small bodied odontocetes. |
| Databáze: | OpenAIRE |
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