Directional biosonar beams allow echolocating harbour porpoises to actively discriminate and intercept closely spaced targets
PhD funding was provided by Danmarks Grundforskningsfond (Danish National Research Council) grants to P.T.M. (27125). This, along with Office of Naval Research Global (ONR) awards N00014-18-1-2062 and N00014-20-1-2709, covered research time at Fjord & Bælt. Echolocating toothed whales face the p...
Published in: | Journal of Experimental Biology |
---|---|
Main Authors: | , , |
Other Authors: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2022
|
Subjects: | |
Online Access: | http://hdl.handle.net/10023/25845 https://doi.org/10.1242/jeb.242779 |
id |
ftstandrewserep:oai:research-repository.st-andrews.ac.uk:10023/25845 |
---|---|
record_format |
openpolar |
spelling |
ftstandrewserep:oai:research-repository.st-andrews.ac.uk:10023/25845 2023-07-02T03:33:28+02:00 Directional biosonar beams allow echolocating harbour porpoises to actively discriminate and intercept closely spaced targets Malinka, Chloe Elizabeth Rojano-Donante, Laia Madsen, Peter T University of St Andrews. School of Biology 2022-08-13 15 application/pdf http://hdl.handle.net/10023/25845 https://doi.org/10.1242/jeb.242779 eng eng Journal of Experimental Biology Malinka , C E , Rojano-Donante , L & Madsen , P T 2021 , ' Directional biosonar beams allow echolocating harbour porpoises to actively discriminate and intercept closely spaced targets ' , Journal of Experimental Biology , vol. 224 , no. 16 , jeb242779 . https://doi.org/10.1242/jeb.242779 0022-0949 PURE: 279456298 PURE UUID: aba2361b-d63b-452f-8da5-87b98a8fe0c4 Scopus: 85113286700 http://hdl.handle.net/10023/25845 https://doi.org/10.1242/jeb.242779 Copyright © 2021 The Author(s). Published by The Company of Biologists Ltd. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the final published version of the work, which was originally published at https://doi.org/10.1242/jeb.242779. Echolocation Biosonar Acoustic gaze Acoustic field of view Echo stream Auditory scene analysis GC Oceanography QH301 Biology DAS NIS GC QH301 Journal article 2022 ftstandrewserep https://doi.org/10.1242/jeb.242779 2023-06-13T18:30:13Z PhD funding was provided by Danmarks Grundforskningsfond (Danish National Research Council) grants to P.T.M. (27125). This, along with Office of Naval Research Global (ONR) awards N00014-18-1-2062 and N00014-20-1-2709, covered research time at Fjord & Bælt. Echolocating toothed whales face the problem that high sound speeds in water mean that echoes from closely spaced targets will arrive at time delays within their reported auditory integration time of some 264 µs. Here, we test the hypothesis that echolocating harbour porpoises cannot resolve and discriminate targets within a clutter interference zone given by their integration time. To do this, we trained two harbour porpoises (Phocoena phocoena) to actively approach and choose between two spherical targets at four varying inter-target distances (13.5, 27, 56 and 108 cm) in a two-alternative forced-choice task. The free-swimming, blindfolded porpoises were tagged with a sound and movement tag (DTAG4) to record their echoic scene and acoustic outputs. The known ranges between targets and the porpoise, combined with the sound levels received on target-mounted hydrophones revealed how the porpoises controlled their acoustic gaze. When targets were close together, the discrimination task was more difficult because of smaller echo time delays and lower echo level ratios between the targets. Under these conditions, buzzes were longer and started from farther away, source levels were reduced at short ranges, and the porpoises clicked faster, scanned across the targets more, and delayed making their discrimination decision until closer to the target. We conclude that harbour porpoises can resolve and discriminate closely spaced targets, suggesting a clutter rejection zone much shorter than their auditory integration time, and that such clutter rejection is greatly aided by spatial filtering with their directional biosonar beam. Publisher PDF Peer reviewed Article in Journal/Newspaper Phocoena phocoena toothed whales University of St Andrews: Digital Research Repository Journal of Experimental Biology 224 16 |
institution |
Open Polar |
collection |
University of St Andrews: Digital Research Repository |
op_collection_id |
ftstandrewserep |
language |
English |
topic |
Echolocation Biosonar Acoustic gaze Acoustic field of view Echo stream Auditory scene analysis GC Oceanography QH301 Biology DAS NIS GC QH301 |
spellingShingle |
Echolocation Biosonar Acoustic gaze Acoustic field of view Echo stream Auditory scene analysis GC Oceanography QH301 Biology DAS NIS GC QH301 Malinka, Chloe Elizabeth Rojano-Donante, Laia Madsen, Peter T Directional biosonar beams allow echolocating harbour porpoises to actively discriminate and intercept closely spaced targets |
topic_facet |
Echolocation Biosonar Acoustic gaze Acoustic field of view Echo stream Auditory scene analysis GC Oceanography QH301 Biology DAS NIS GC QH301 |
description |
PhD funding was provided by Danmarks Grundforskningsfond (Danish National Research Council) grants to P.T.M. (27125). This, along with Office of Naval Research Global (ONR) awards N00014-18-1-2062 and N00014-20-1-2709, covered research time at Fjord & Bælt. Echolocating toothed whales face the problem that high sound speeds in water mean that echoes from closely spaced targets will arrive at time delays within their reported auditory integration time of some 264 µs. Here, we test the hypothesis that echolocating harbour porpoises cannot resolve and discriminate targets within a clutter interference zone given by their integration time. To do this, we trained two harbour porpoises (Phocoena phocoena) to actively approach and choose between two spherical targets at four varying inter-target distances (13.5, 27, 56 and 108 cm) in a two-alternative forced-choice task. The free-swimming, blindfolded porpoises were tagged with a sound and movement tag (DTAG4) to record their echoic scene and acoustic outputs. The known ranges between targets and the porpoise, combined with the sound levels received on target-mounted hydrophones revealed how the porpoises controlled their acoustic gaze. When targets were close together, the discrimination task was more difficult because of smaller echo time delays and lower echo level ratios between the targets. Under these conditions, buzzes were longer and started from farther away, source levels were reduced at short ranges, and the porpoises clicked faster, scanned across the targets more, and delayed making their discrimination decision until closer to the target. We conclude that harbour porpoises can resolve and discriminate closely spaced targets, suggesting a clutter rejection zone much shorter than their auditory integration time, and that such clutter rejection is greatly aided by spatial filtering with their directional biosonar beam. Publisher PDF Peer reviewed |
author2 |
University of St Andrews. School of Biology |
format |
Article in Journal/Newspaper |
author |
Malinka, Chloe Elizabeth Rojano-Donante, Laia Madsen, Peter T |
author_facet |
Malinka, Chloe Elizabeth Rojano-Donante, Laia Madsen, Peter T |
author_sort |
Malinka, Chloe Elizabeth |
title |
Directional biosonar beams allow echolocating harbour porpoises to actively discriminate and intercept closely spaced targets |
title_short |
Directional biosonar beams allow echolocating harbour porpoises to actively discriminate and intercept closely spaced targets |
title_full |
Directional biosonar beams allow echolocating harbour porpoises to actively discriminate and intercept closely spaced targets |
title_fullStr |
Directional biosonar beams allow echolocating harbour porpoises to actively discriminate and intercept closely spaced targets |
title_full_unstemmed |
Directional biosonar beams allow echolocating harbour porpoises to actively discriminate and intercept closely spaced targets |
title_sort |
directional biosonar beams allow echolocating harbour porpoises to actively discriminate and intercept closely spaced targets |
publishDate |
2022 |
url |
http://hdl.handle.net/10023/25845 https://doi.org/10.1242/jeb.242779 |
genre |
Phocoena phocoena toothed whales |
genre_facet |
Phocoena phocoena toothed whales |
op_relation |
Journal of Experimental Biology Malinka , C E , Rojano-Donante , L & Madsen , P T 2021 , ' Directional biosonar beams allow echolocating harbour porpoises to actively discriminate and intercept closely spaced targets ' , Journal of Experimental Biology , vol. 224 , no. 16 , jeb242779 . https://doi.org/10.1242/jeb.242779 0022-0949 PURE: 279456298 PURE UUID: aba2361b-d63b-452f-8da5-87b98a8fe0c4 Scopus: 85113286700 http://hdl.handle.net/10023/25845 https://doi.org/10.1242/jeb.242779 |
op_rights |
Copyright © 2021 The Author(s). Published by The Company of Biologists Ltd. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the final published version of the work, which was originally published at https://doi.org/10.1242/jeb.242779. |
op_doi |
https://doi.org/10.1242/jeb.242779 |
container_title |
Journal of Experimental Biology |
container_volume |
224 |
container_issue |
16 |
_version_ |
1770273434089029632 |