Department of Biology

Aarhus University Seal / Aarhus Universitets segl

Professor Peter Teglberg Madsen

Amazon river dolphins (Inia geoffrensis) use a high-frequency short-range biosonar

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaperJournal articleResearchpeer-review

Standard

Amazon river dolphins (Inia geoffrensis) use a high-frequency short-range biosonar. / Ladegaard, Michael; Jensen, Frants Havmand; de Freitas, Mafalda; da Silva, Vera Maria Ferreira; Madsen, Peter Teglberg.

In: The Journal of Experimental Biology, Vol. 218, No. 19, 01.10.2015, p. 3091-3101.

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaperJournal articleResearchpeer-review

Harvard

Ladegaard, M, Jensen, FH, de Freitas, M, da Silva, VMF & Madsen, PT 2015, 'Amazon river dolphins (Inia geoffrensis) use a high-frequency short-range biosonar', The Journal of Experimental Biology, vol. 218, no. 19, pp. 3091-3101. https://doi.org/10.1242/jeb.120501

APA

Ladegaard, M., Jensen, F. H., de Freitas, M., da Silva, V. M. F., & Madsen, P. T. (2015). Amazon river dolphins (Inia geoffrensis) use a high-frequency short-range biosonar. The Journal of Experimental Biology, 218(19), 3091-3101. https://doi.org/10.1242/jeb.120501

CBE

Ladegaard M, Jensen FH, de Freitas M, da Silva VMF, Madsen PT. 2015. Amazon river dolphins (Inia geoffrensis) use a high-frequency short-range biosonar. The Journal of Experimental Biology. 218(19):3091-3101. https://doi.org/10.1242/jeb.120501

MLA

Vancouver

Ladegaard M, Jensen FH, de Freitas M, da Silva VMF, Madsen PT. Amazon river dolphins (Inia geoffrensis) use a high-frequency short-range biosonar. The Journal of Experimental Biology. 2015 Oct 1;218(19):3091-3101. https://doi.org/10.1242/jeb.120501

Author

Ladegaard, Michael ; Jensen, Frants Havmand ; de Freitas, Mafalda ; da Silva, Vera Maria Ferreira ; Madsen, Peter Teglberg. / Amazon river dolphins (Inia geoffrensis) use a high-frequency short-range biosonar. In: The Journal of Experimental Biology. 2015 ; Vol. 218, No. 19. pp. 3091-3101.

Bibtex

@article{8ad00996584c487bbde61d38405dcc8c,
title = "Amazon river dolphins (Inia geoffrensis) use a high-frequency short-range biosonar",
abstract = "Toothed whales produce echolocation clicks with source parameters related to body size; however, it may be equally important to consider the influence of habitat, as suggested by studies on echolocating bats. A few toothed whale species have fully adapted to river systems, where sonar operation is likely to result in higher clutter and reverberation levels than those experienced by most toothed whales at sea because of the shallow water and dense vegetation. To test the hypothesis that habitat shapes the evolution of toothed whale biosonar parameters by promoting simpler auditory scenes to interpret in acoustically complex habitats, echolocation clicks of wild Amazon river dolphins were recorded using a vertical seven-hydrophone array. We identified 404 on-axis biosonar clicks having a mean SLpp of 190.3±6.1 dB re. 1 μPa, mean SLEFD of 132.1±6.0 dB re. 1 μPa2s, mean Fc of 101.2±10.5 kHz, mean BWRMS of 29.3±4.3 kHz and mean ICI of 35.1±17.9 ms. Piston fit modelling resulted in an estimated half-power beamwidth of 10.2 deg (95% CI: 9.6–10.5 deg) and directivity index of 25.2 dB (95% CI: 24.9– 25.7 dB). These results support the hypothesis that river-dwelling toothed whales operate their biosonars at lower amplitude and higher sampling rates than similar-sized marine species without sacrificing high directivity, in order to provide high update rates in acoustically complex habitats and simplify auditory scenes through reduced clutter and reverberation levels. We conclude that habitat, along with body size, is an important evolutionary driver of source parameters in toothed whale biosonars.",
keywords = "Beamwidth, Clutter, Directionality, Echolocation, Habitat, Toothed whale, Beamwidth, Clutter, Directionality, Echolocation, Habitat, Toothed whale",
author = "Michael Ladegaard and Jensen, {Frants Havmand} and {de Freitas}, Mafalda and {da Silva}, {Vera Maria Ferreira} and Madsen, {Peter Teglberg}",
year = "2015",
month = oct,
day = "1",
doi = "10.1242/jeb.120501",
language = "English",
volume = "218",
pages = "3091--3101",
journal = "BRITISH JOURNAL OF EXPERIMENTAL BIOLOGY",
issn = "0022-0949",
publisher = "The/Company of Biologists Ltd.",
number = "19",

}

RIS

TY - JOUR

T1 - Amazon river dolphins (Inia geoffrensis) use a high-frequency short-range biosonar

AU - Ladegaard, Michael

AU - Jensen, Frants Havmand

AU - de Freitas, Mafalda

AU - da Silva, Vera Maria Ferreira

AU - Madsen, Peter Teglberg

PY - 2015/10/1

Y1 - 2015/10/1

N2 - Toothed whales produce echolocation clicks with source parameters related to body size; however, it may be equally important to consider the influence of habitat, as suggested by studies on echolocating bats. A few toothed whale species have fully adapted to river systems, where sonar operation is likely to result in higher clutter and reverberation levels than those experienced by most toothed whales at sea because of the shallow water and dense vegetation. To test the hypothesis that habitat shapes the evolution of toothed whale biosonar parameters by promoting simpler auditory scenes to interpret in acoustically complex habitats, echolocation clicks of wild Amazon river dolphins were recorded using a vertical seven-hydrophone array. We identified 404 on-axis biosonar clicks having a mean SLpp of 190.3±6.1 dB re. 1 μPa, mean SLEFD of 132.1±6.0 dB re. 1 μPa2s, mean Fc of 101.2±10.5 kHz, mean BWRMS of 29.3±4.3 kHz and mean ICI of 35.1±17.9 ms. Piston fit modelling resulted in an estimated half-power beamwidth of 10.2 deg (95% CI: 9.6–10.5 deg) and directivity index of 25.2 dB (95% CI: 24.9– 25.7 dB). These results support the hypothesis that river-dwelling toothed whales operate their biosonars at lower amplitude and higher sampling rates than similar-sized marine species without sacrificing high directivity, in order to provide high update rates in acoustically complex habitats and simplify auditory scenes through reduced clutter and reverberation levels. We conclude that habitat, along with body size, is an important evolutionary driver of source parameters in toothed whale biosonars.

AB - Toothed whales produce echolocation clicks with source parameters related to body size; however, it may be equally important to consider the influence of habitat, as suggested by studies on echolocating bats. A few toothed whale species have fully adapted to river systems, where sonar operation is likely to result in higher clutter and reverberation levels than those experienced by most toothed whales at sea because of the shallow water and dense vegetation. To test the hypothesis that habitat shapes the evolution of toothed whale biosonar parameters by promoting simpler auditory scenes to interpret in acoustically complex habitats, echolocation clicks of wild Amazon river dolphins were recorded using a vertical seven-hydrophone array. We identified 404 on-axis biosonar clicks having a mean SLpp of 190.3±6.1 dB re. 1 μPa, mean SLEFD of 132.1±6.0 dB re. 1 μPa2s, mean Fc of 101.2±10.5 kHz, mean BWRMS of 29.3±4.3 kHz and mean ICI of 35.1±17.9 ms. Piston fit modelling resulted in an estimated half-power beamwidth of 10.2 deg (95% CI: 9.6–10.5 deg) and directivity index of 25.2 dB (95% CI: 24.9– 25.7 dB). These results support the hypothesis that river-dwelling toothed whales operate their biosonars at lower amplitude and higher sampling rates than similar-sized marine species without sacrificing high directivity, in order to provide high update rates in acoustically complex habitats and simplify auditory scenes through reduced clutter and reverberation levels. We conclude that habitat, along with body size, is an important evolutionary driver of source parameters in toothed whale biosonars.

KW - Beamwidth, Clutter, Directionality, Echolocation, Habitat, Toothed whale

KW - Beamwidth, Clutter, Directionality, Echolocation, Habitat, Toothed whale

U2 - 10.1242/jeb.120501

DO - 10.1242/jeb.120501

M3 - Journal article

C2 - 26447198

VL - 218

SP - 3091

EP - 3101

JO - BRITISH JOURNAL OF EXPERIMENTAL BIOLOGY

JF - BRITISH JOURNAL OF EXPERIMENTAL BIOLOGY

SN - 0022-0949

IS - 19

ER -