Heaviside's dolphins (Cephalorhynchus heavisidii) relax acoustic crypsis to increase communication range
Author Posting. © The Author(s), 2018. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Proceedings of...
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ftwhoas:oai:darchive.mblwhoilibrary.org:1912/10505 2023-05-15T18:33:33+02:00 Heaviside's dolphins (Cephalorhynchus heavisidii) relax acoustic crypsis to increase communication range Martin, Morgan J. Gridley, Tess Elwen, Simon H. Jensen, Frants H. 2018-06 https://hdl.handle.net/1912/10505 en_US eng https://doi.org/10.1098/rspb.2018.1178 https://hdl.handle.net/1912/10505 Acoustic crypsis Active space Communication Echolocation Heaviside’s dolphin Narrowband high-frequency clicks Preprint 2018 ftwhoas https://doi.org/10.1098/rspb.2018.1178 2022-05-28T23:00:28Z Author Posting. © The Author(s), 2018. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Proceedings of the Royal Society B. Biological Sciences 285 (2018): 20181178, doi:10.1098/rspb.2018.1178. The costs of predation may exert significant pressure on the mode of communication used by an animal, and many species balance the benefits of communication (e.g. mate attraction) against the potential risk of predation. Four groups of toothed whales have independently evolved narrowband high-frequency (NBHF) echolocation signals. These signals help NBHF species avoid predation through acoustic crypsis by echolocating and communicating at frequencies inaudible to predators such as mammal-eating killer whales. Heaviside’s dolphins (Cephalorhynchus heavisidii) are thought to exclusively produce NBHF echolocation clicks with a centroid frequency around 125 kHz and little to no energy below 100 kHz. To test this, we recorded wild Heaviside’s dolphins in a sheltered bay in Namibia. We demonstrate that Heaviside’s dolphins produce a second type of click with lower frequency and broader bandwidth in a frequency range that is audible to killer whales. These clicks are used in burst-pulses and occasional click series but not foraging buzzes. We evaluate three different hypotheses and conclude that the most likely benefit of these clicks is to decrease transmission directivity and increase conspecific communication range. The expected increase in active space depends on background noise but ranges from 2.5 (Wenz Sea State 6) to 5 times (Wenz Sea State 1) the active space of NBHF signals. This dual click strategy therefore allows these social dolphins to maintain acoustic crypsis during navigation and foraging, and to selectively relax their crypsis to facilitate communication with conspecifics. This research was supported by a Fulbright ... Report toothed whales Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Proceedings of the Royal Society B: Biological Sciences 285 1883 20181178 |
institution |
Open Polar |
collection |
Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) |
op_collection_id |
ftwhoas |
language |
English |
topic |
Acoustic crypsis Active space Communication Echolocation Heaviside’s dolphin Narrowband high-frequency clicks |
spellingShingle |
Acoustic crypsis Active space Communication Echolocation Heaviside’s dolphin Narrowband high-frequency clicks Martin, Morgan J. Gridley, Tess Elwen, Simon H. Jensen, Frants H. Heaviside's dolphins (Cephalorhynchus heavisidii) relax acoustic crypsis to increase communication range |
topic_facet |
Acoustic crypsis Active space Communication Echolocation Heaviside’s dolphin Narrowband high-frequency clicks |
description |
Author Posting. © The Author(s), 2018. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Proceedings of the Royal Society B. Biological Sciences 285 (2018): 20181178, doi:10.1098/rspb.2018.1178. The costs of predation may exert significant pressure on the mode of communication used by an animal, and many species balance the benefits of communication (e.g. mate attraction) against the potential risk of predation. Four groups of toothed whales have independently evolved narrowband high-frequency (NBHF) echolocation signals. These signals help NBHF species avoid predation through acoustic crypsis by echolocating and communicating at frequencies inaudible to predators such as mammal-eating killer whales. Heaviside’s dolphins (Cephalorhynchus heavisidii) are thought to exclusively produce NBHF echolocation clicks with a centroid frequency around 125 kHz and little to no energy below 100 kHz. To test this, we recorded wild Heaviside’s dolphins in a sheltered bay in Namibia. We demonstrate that Heaviside’s dolphins produce a second type of click with lower frequency and broader bandwidth in a frequency range that is audible to killer whales. These clicks are used in burst-pulses and occasional click series but not foraging buzzes. We evaluate three different hypotheses and conclude that the most likely benefit of these clicks is to decrease transmission directivity and increase conspecific communication range. The expected increase in active space depends on background noise but ranges from 2.5 (Wenz Sea State 6) to 5 times (Wenz Sea State 1) the active space of NBHF signals. This dual click strategy therefore allows these social dolphins to maintain acoustic crypsis during navigation and foraging, and to selectively relax their crypsis to facilitate communication with conspecifics. This research was supported by a Fulbright ... |
format |
Report |
author |
Martin, Morgan J. Gridley, Tess Elwen, Simon H. Jensen, Frants H. |
author_facet |
Martin, Morgan J. Gridley, Tess Elwen, Simon H. Jensen, Frants H. |
author_sort |
Martin, Morgan J. |
title |
Heaviside's dolphins (Cephalorhynchus heavisidii) relax acoustic crypsis to increase communication range |
title_short |
Heaviside's dolphins (Cephalorhynchus heavisidii) relax acoustic crypsis to increase communication range |
title_full |
Heaviside's dolphins (Cephalorhynchus heavisidii) relax acoustic crypsis to increase communication range |
title_fullStr |
Heaviside's dolphins (Cephalorhynchus heavisidii) relax acoustic crypsis to increase communication range |
title_full_unstemmed |
Heaviside's dolphins (Cephalorhynchus heavisidii) relax acoustic crypsis to increase communication range |
title_sort |
heaviside's dolphins (cephalorhynchus heavisidii) relax acoustic crypsis to increase communication range |
publishDate |
2018 |
url |
https://hdl.handle.net/1912/10505 |
genre |
toothed whales |
genre_facet |
toothed whales |
op_relation |
https://doi.org/10.1098/rspb.2018.1178 https://hdl.handle.net/1912/10505 |
op_doi |
https://doi.org/10.1098/rspb.2018.1178 |
container_title |
Proceedings of the Royal Society B: Biological Sciences |
container_volume |
285 |
container_issue |
1883 |
container_start_page |
20181178 |
_version_ |
1766218178473492480 |