Context-dependent biosonar adjustments during active target approaches in echolocating harbour porpoises
Echolocating mammals generally target individual prey items by transitioning through the biosonar phases of search (slow-rate, high-amplitude outputs), approach (gradually increasing rate and decreasing output amplitude) and buzzing (high-rate, low-amplitude outputs). The range to the main target of...
Published in: | Journal of Experimental Biology |
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Language: | English |
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Online Access: | https://pure.au.dk/portal/da/publications/contextdependent-biosonar-adjustments-during-active-target-approaches-in-echolocating-harbour-porpoises(653ee66f-b119-4442-ae68-fc1d544e81c4).html https://doi.org/10.1242/jeb.206169 https://pure.au.dk/ws/files/195221517/Context_dependent_biosonar_adjustments_during_active_target_approaches_in_echolocating_harbour_porpoises.pdf http://www.scopus.com/inward/record.url?scp=85071701307&partnerID=8YFLogxK |
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ftuniaarhuspubl:oai:pure.atira.dk:publications/653ee66f-b119-4442-ae68-fc1d544e81c4 2023-05-15T17:59:14+02:00 Context-dependent biosonar adjustments during active target approaches in echolocating harbour porpoises Ladegaard, Michael Madsen, Peter Teglberg 2019-08 application/pdf https://pure.au.dk/portal/da/publications/contextdependent-biosonar-adjustments-during-active-target-approaches-in-echolocating-harbour-porpoises(653ee66f-b119-4442-ae68-fc1d544e81c4).html https://doi.org/10.1242/jeb.206169 https://pure.au.dk/ws/files/195221517/Context_dependent_biosonar_adjustments_during_active_target_approaches_in_echolocating_harbour_porpoises.pdf http://www.scopus.com/inward/record.url?scp=85071701307&partnerID=8YFLogxK eng eng info:eu-repo/semantics/openAccess Ladegaard , M & Madsen , P T 2019 , ' Context-dependent biosonar adjustments during active target approaches in echolocating harbour porpoises ' , Journal of Experimental Biology , vol. 222 , no. 16 , jeb206169 . https://doi.org/10.1242/jeb.206169 Echolocation Interclick interval Phocoena phocoena Source level Target range Toothed whale article 2019 ftuniaarhuspubl https://doi.org/10.1242/jeb.206169 2020-08-26T22:42:31Z Echolocating mammals generally target individual prey items by transitioning through the biosonar phases of search (slow-rate, high-amplitude outputs), approach (gradually increasing rate and decreasing output amplitude) and buzzing (high-rate, low-amplitude outputs). The range to the main target of interest is often considered the key or sole driver of such biosonar adjustments of acoustic gaze. However, the actively generated auditory scene of an echolocator invariably comprises a large number of other reflectors and noise sources that likely also impact the biosonar strategies and source parameters implemented by an echolocating animal in time and space. In toothed whales, the importance of context on biosonar adjustments is largely unknown. To address this, we trained two harbour porpoises to actively approach the same sound recording target over the same approach distance in two highly different environments: a PVC-lined pool and a semi-natural net pen in a harbour, while blind-folded and wearing a sound recording tag (DTAG-4). We show that the approaching porpoises used considerably shorter interclick intervals (ICIs) in the pool than in the net pen, except during the buzz phase, where slightly longer ICIs were used in the pool. We further show that average click source levels were 4–7 dB higher in the net pen. Because of the very low-level in-band ambient noise in both environments, we posit that the porpoises adapted their echolocation strategy to the different reverberation levels between the two settings. We demonstrate that harbour porpoises use different echolocation strategies and biosonar parameters in two different environments for solving an otherwise identical target approach task and thus highlight that biosonar adjustments are both range and context dependent. Article in Journal/Newspaper Phocoena phocoena toothed whale toothed whales Aarhus University: Research Journal of Experimental Biology |
institution |
Open Polar |
collection |
Aarhus University: Research |
op_collection_id |
ftuniaarhuspubl |
language |
English |
topic |
Echolocation Interclick interval Phocoena phocoena Source level Target range Toothed whale |
spellingShingle |
Echolocation Interclick interval Phocoena phocoena Source level Target range Toothed whale Ladegaard, Michael Madsen, Peter Teglberg Context-dependent biosonar adjustments during active target approaches in echolocating harbour porpoises |
topic_facet |
Echolocation Interclick interval Phocoena phocoena Source level Target range Toothed whale |
description |
Echolocating mammals generally target individual prey items by transitioning through the biosonar phases of search (slow-rate, high-amplitude outputs), approach (gradually increasing rate and decreasing output amplitude) and buzzing (high-rate, low-amplitude outputs). The range to the main target of interest is often considered the key or sole driver of such biosonar adjustments of acoustic gaze. However, the actively generated auditory scene of an echolocator invariably comprises a large number of other reflectors and noise sources that likely also impact the biosonar strategies and source parameters implemented by an echolocating animal in time and space. In toothed whales, the importance of context on biosonar adjustments is largely unknown. To address this, we trained two harbour porpoises to actively approach the same sound recording target over the same approach distance in two highly different environments: a PVC-lined pool and a semi-natural net pen in a harbour, while blind-folded and wearing a sound recording tag (DTAG-4). We show that the approaching porpoises used considerably shorter interclick intervals (ICIs) in the pool than in the net pen, except during the buzz phase, where slightly longer ICIs were used in the pool. We further show that average click source levels were 4–7 dB higher in the net pen. Because of the very low-level in-band ambient noise in both environments, we posit that the porpoises adapted their echolocation strategy to the different reverberation levels between the two settings. We demonstrate that harbour porpoises use different echolocation strategies and biosonar parameters in two different environments for solving an otherwise identical target approach task and thus highlight that biosonar adjustments are both range and context dependent. |
format |
Article in Journal/Newspaper |
author |
Ladegaard, Michael Madsen, Peter Teglberg |
author_facet |
Ladegaard, Michael Madsen, Peter Teglberg |
author_sort |
Ladegaard, Michael |
title |
Context-dependent biosonar adjustments during active target approaches in echolocating harbour porpoises |
title_short |
Context-dependent biosonar adjustments during active target approaches in echolocating harbour porpoises |
title_full |
Context-dependent biosonar adjustments during active target approaches in echolocating harbour porpoises |
title_fullStr |
Context-dependent biosonar adjustments during active target approaches in echolocating harbour porpoises |
title_full_unstemmed |
Context-dependent biosonar adjustments during active target approaches in echolocating harbour porpoises |
title_sort |
context-dependent biosonar adjustments during active target approaches in echolocating harbour porpoises |
publishDate |
2019 |
url |
https://pure.au.dk/portal/da/publications/contextdependent-biosonar-adjustments-during-active-target-approaches-in-echolocating-harbour-porpoises(653ee66f-b119-4442-ae68-fc1d544e81c4).html https://doi.org/10.1242/jeb.206169 https://pure.au.dk/ws/files/195221517/Context_dependent_biosonar_adjustments_during_active_target_approaches_in_echolocating_harbour_porpoises.pdf http://www.scopus.com/inward/record.url?scp=85071701307&partnerID=8YFLogxK |
genre |
Phocoena phocoena toothed whale toothed whales |
genre_facet |
Phocoena phocoena toothed whale toothed whales |
op_source |
Ladegaard , M & Madsen , P T 2019 , ' Context-dependent biosonar adjustments during active target approaches in echolocating harbour porpoises ' , Journal of Experimental Biology , vol. 222 , no. 16 , jeb206169 . https://doi.org/10.1242/jeb.206169 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1242/jeb.206169 |
container_title |
Journal of Experimental Biology |
_version_ |
1766168004008083456 |