Biosonar adjustments to target range of echolocating bottlenose dolphins ( Tursiops sp. ) in the wild
Toothed whales use echolocation to locate and track prey. Most knowledge of toothed whale echolocation stems from studies on trained animals, and little is known about how toothed whales regulate and use their biosonar systems in the wild. Recent research suggests that an automatic gain control mech...
Published in: | Journal of Experimental Biology |
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Language: | English |
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2009
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ftuniaarhuspubl:oai:pure.atira.dk:publications/1687de60-1245-11de-8317-000ea68e967b 2023-06-11T04:17:20+02:00 Biosonar adjustments to target range of echolocating bottlenose dolphins ( Tursiops sp. ) in the wild Jensen, Frants Havmand Bejder, Lars Wahlberg, Magnus Madsen, Peter Teglberg 2009 https://pure.au.dk/portal/da/publications/biosonar-adjustments-to-target-range-of-echolocating-bottlenose-dolphins-tursiops-sp-in-the-wild(1687de60-1245-11de-8317-000ea68e967b).html https://doi.org/10.1242/jeb.025619 http://jeb.biologists.org/cgi/reprint/212/8/1078.pdf?ijkey=szLrCizgNhWjzpn&keytype=finite eng eng info:eu-repo/semantics/restrictedAccess Jensen , F H , Bejder , L , Wahlberg , M & Madsen , P T 2009 , ' Biosonar adjustments to target range of echolocating bottlenose dolphins ( Tursiops sp. ) in the wild ' , Journal of Experimental Biology , vol. 212 , pp. 1078-1086 . https://doi.org/10.1242/jeb.025619 Tursiops Delfin Hval Ekkolokation Biosonar Lydproduktion Automatic Gain Control Dolphin Whale Echolocation Sound Production article 2009 ftuniaarhuspubl https://doi.org/10.1242/jeb.025619 2023-04-19T22:56:30Z Toothed whales use echolocation to locate and track prey. Most knowledge of toothed whale echolocation stems from studies on trained animals, and little is known about how toothed whales regulate and use their biosonar systems in the wild. Recent research suggests that an automatic gain control mechanism in delphinid biosonars adjusts the biosonar output to the one-way transmission loss to the target, possibly a consequence of pneumatic restrictions in how fast the sound generator can be actuated and still maintain high outputs. This study examines the relationships between target range (R), click intervals, and source levels of wild bottlenose dolphins (Tursiops sp.) by recording regular (non-buzz) echolocation clicks with a linear hydrophone array. Dolphins clicked faster with decreasing distance to the array, reflecting a decreasing delay between the outgoing echolocation click and the returning array echo. However, for interclick intervals longer than 30–40 ms, source levels were not limited by the repetition rate. Thus, pneumatic constraints in the sound-production apparatus cannot account for source level adjustments to range as a possible automatic gain control mechanism for target ranges longer than a few body lengths of the dolphin. Source level estimates drop with reducing range between the echolocating dolphins and the target as a function of 17 log(R). This may indicate either (1) an active form of time-varying gain in the biosonar independent of click intervals or (2) a bias in array recordings towards a 20 log(R) relationship for apparent source levels introduced by a threshold on received click levels included in the analysis. Article in Journal/Newspaper toothed whale toothed whales Aarhus University: Research Journal of Experimental Biology 212 8 1078 1086 |
institution |
Open Polar |
collection |
Aarhus University: Research |
op_collection_id |
ftuniaarhuspubl |
language |
English |
topic |
Tursiops Delfin Hval Ekkolokation Biosonar Lydproduktion Automatic Gain Control Dolphin Whale Echolocation Sound Production |
spellingShingle |
Tursiops Delfin Hval Ekkolokation Biosonar Lydproduktion Automatic Gain Control Dolphin Whale Echolocation Sound Production Jensen, Frants Havmand Bejder, Lars Wahlberg, Magnus Madsen, Peter Teglberg Biosonar adjustments to target range of echolocating bottlenose dolphins ( Tursiops sp. ) in the wild |
topic_facet |
Tursiops Delfin Hval Ekkolokation Biosonar Lydproduktion Automatic Gain Control Dolphin Whale Echolocation Sound Production |
description |
Toothed whales use echolocation to locate and track prey. Most knowledge of toothed whale echolocation stems from studies on trained animals, and little is known about how toothed whales regulate and use their biosonar systems in the wild. Recent research suggests that an automatic gain control mechanism in delphinid biosonars adjusts the biosonar output to the one-way transmission loss to the target, possibly a consequence of pneumatic restrictions in how fast the sound generator can be actuated and still maintain high outputs. This study examines the relationships between target range (R), click intervals, and source levels of wild bottlenose dolphins (Tursiops sp.) by recording regular (non-buzz) echolocation clicks with a linear hydrophone array. Dolphins clicked faster with decreasing distance to the array, reflecting a decreasing delay between the outgoing echolocation click and the returning array echo. However, for interclick intervals longer than 30–40 ms, source levels were not limited by the repetition rate. Thus, pneumatic constraints in the sound-production apparatus cannot account for source level adjustments to range as a possible automatic gain control mechanism for target ranges longer than a few body lengths of the dolphin. Source level estimates drop with reducing range between the echolocating dolphins and the target as a function of 17 log(R). This may indicate either (1) an active form of time-varying gain in the biosonar independent of click intervals or (2) a bias in array recordings towards a 20 log(R) relationship for apparent source levels introduced by a threshold on received click levels included in the analysis. |
format |
Article in Journal/Newspaper |
author |
Jensen, Frants Havmand Bejder, Lars Wahlberg, Magnus Madsen, Peter Teglberg |
author_facet |
Jensen, Frants Havmand Bejder, Lars Wahlberg, Magnus Madsen, Peter Teglberg |
author_sort |
Jensen, Frants Havmand |
title |
Biosonar adjustments to target range of echolocating bottlenose dolphins ( Tursiops sp. ) in the wild |
title_short |
Biosonar adjustments to target range of echolocating bottlenose dolphins ( Tursiops sp. ) in the wild |
title_full |
Biosonar adjustments to target range of echolocating bottlenose dolphins ( Tursiops sp. ) in the wild |
title_fullStr |
Biosonar adjustments to target range of echolocating bottlenose dolphins ( Tursiops sp. ) in the wild |
title_full_unstemmed |
Biosonar adjustments to target range of echolocating bottlenose dolphins ( Tursiops sp. ) in the wild |
title_sort |
biosonar adjustments to target range of echolocating bottlenose dolphins ( tursiops sp. ) in the wild |
publishDate |
2009 |
url |
https://pure.au.dk/portal/da/publications/biosonar-adjustments-to-target-range-of-echolocating-bottlenose-dolphins-tursiops-sp-in-the-wild(1687de60-1245-11de-8317-000ea68e967b).html https://doi.org/10.1242/jeb.025619 http://jeb.biologists.org/cgi/reprint/212/8/1078.pdf?ijkey=szLrCizgNhWjzpn&keytype=finite |
genre |
toothed whale toothed whales |
genre_facet |
toothed whale toothed whales |
op_source |
Jensen , F H , Bejder , L , Wahlberg , M & Madsen , P T 2009 , ' Biosonar adjustments to target range of echolocating bottlenose dolphins ( Tursiops sp. ) in the wild ' , Journal of Experimental Biology , vol. 212 , pp. 1078-1086 . https://doi.org/10.1242/jeb.025619 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1242/jeb.025619 |
container_title |
Journal of Experimental Biology |
container_volume |
212 |
container_issue |
8 |
container_start_page |
1078 |
op_container_end_page |
1086 |
_version_ |
1768376424357429248 |