Clicking throughout the year : sperm whale clicks in relation to environmental conditions off the west coast of South Africa
Knowledge of cetacean occurrence and behaviour in southern African waters is limited, and passive acoustic monitoring has the potential to address this gap efficiently. Seasonal acoustic occurrence and diel-vocalizing patterns of sperm whales in relation to environmental conditions are described her...
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Language: | English |
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Inter Research
2020
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Online Access: | http://hdl.handle.net/2263/79159 https://doi.org/10.3354/esr01089 |
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ftunivpretoria:oai:repository.up.ac.za:2263/79159 2023-05-15T18:26:33+02:00 Clicking throughout the year : sperm whale clicks in relation to environmental conditions off the west coast of South Africa Shabangu, Fannie Welcome Andrew, Rex K. 2020-12 http://hdl.handle.net/2263/79159 https://doi.org/10.3354/esr01089 en eng Inter Research http://hdl.handle.net/2263/79159 Shabangu FW, Andrew RK (2020) Clicking throughout the year: sperm whale clicks in relation to environmental conditions off the west coast of South Africa. Endangered Species Research 43:475-494. https://doi.org/10.3354/esr01089. 1863-5407 (print) 1613-4796 (online) doi:10.3354/esr01089 © The authors 2020. Open Access under Creative Commons by Attribution Licence. CC-BY Sperm whales Acoustic occurrence Passive acoustic monitoring Diel behaviour Detection ranges Environmental conditions Random forest model Autonomous acoustic recorder (AAR) South Africa (SA) Article 2020 ftunivpretoria https://doi.org/10.3354/esr01089 2022-05-31T13:28:27Z Knowledge of cetacean occurrence and behaviour in southern African waters is limited, and passive acoustic monitoring has the potential to address this gap efficiently. Seasonal acoustic occurrence and diel-vocalizing patterns of sperm whales in relation to environmental conditions are described here using passive acoustic monitoring data collected off the west coast of South Africa. Four autonomous acoustic recorders (AARs) were deployed on 3 oceanographic moorings from July 2014 to January 2017. Sperm whale clicks were detected year round in most recording sites, with peaks in acoustic occurrence in summer and late winter through spring. Dielvocalizing patterns were detected in winter, spring and summer. Higher percentages of sperm whale clicks were recorded by AARs deployed at 1100 m water depth compared to those concurrently deployed at 850 and 4500 m, likely inferring that the whales exhibited some preference to water depths around 1100 m. Acoustic propagation modelling suggested a maximum detection range of 83 km in winter for sperm whale clicks produced at 1100 m. Random forest models classified daylight regime, sea surface height anomaly and month of the year as the most important predictors of sperm whale acoustic occurrence. The continuous acoustic occurrence of sperm whales suggests that the study area supports large biomasses of prey to sustain this species’ food requirements year round. This is the first study to describe the seasonal acoustic occurrence and diel-vocalizing patterns of sperm whales off the west coast of South Africa, extending knowledge of the species previously available only through whaling records. http://www.int-res.com/journals/esr/esr-home pm2021 Mammal Research Institute Article in Journal/Newspaper Sperm whale University of Pretoria: UPSpace Endangered Species Research 43 475 494 |
institution |
Open Polar |
collection |
University of Pretoria: UPSpace |
op_collection_id |
ftunivpretoria |
language |
English |
topic |
Sperm whales Acoustic occurrence Passive acoustic monitoring Diel behaviour Detection ranges Environmental conditions Random forest model Autonomous acoustic recorder (AAR) South Africa (SA) |
spellingShingle |
Sperm whales Acoustic occurrence Passive acoustic monitoring Diel behaviour Detection ranges Environmental conditions Random forest model Autonomous acoustic recorder (AAR) South Africa (SA) Shabangu, Fannie Welcome Andrew, Rex K. Clicking throughout the year : sperm whale clicks in relation to environmental conditions off the west coast of South Africa |
topic_facet |
Sperm whales Acoustic occurrence Passive acoustic monitoring Diel behaviour Detection ranges Environmental conditions Random forest model Autonomous acoustic recorder (AAR) South Africa (SA) |
description |
Knowledge of cetacean occurrence and behaviour in southern African waters is limited, and passive acoustic monitoring has the potential to address this gap efficiently. Seasonal acoustic occurrence and diel-vocalizing patterns of sperm whales in relation to environmental conditions are described here using passive acoustic monitoring data collected off the west coast of South Africa. Four autonomous acoustic recorders (AARs) were deployed on 3 oceanographic moorings from July 2014 to January 2017. Sperm whale clicks were detected year round in most recording sites, with peaks in acoustic occurrence in summer and late winter through spring. Dielvocalizing patterns were detected in winter, spring and summer. Higher percentages of sperm whale clicks were recorded by AARs deployed at 1100 m water depth compared to those concurrently deployed at 850 and 4500 m, likely inferring that the whales exhibited some preference to water depths around 1100 m. Acoustic propagation modelling suggested a maximum detection range of 83 km in winter for sperm whale clicks produced at 1100 m. Random forest models classified daylight regime, sea surface height anomaly and month of the year as the most important predictors of sperm whale acoustic occurrence. The continuous acoustic occurrence of sperm whales suggests that the study area supports large biomasses of prey to sustain this species’ food requirements year round. This is the first study to describe the seasonal acoustic occurrence and diel-vocalizing patterns of sperm whales off the west coast of South Africa, extending knowledge of the species previously available only through whaling records. http://www.int-res.com/journals/esr/esr-home pm2021 Mammal Research Institute |
format |
Article in Journal/Newspaper |
author |
Shabangu, Fannie Welcome Andrew, Rex K. |
author_facet |
Shabangu, Fannie Welcome Andrew, Rex K. |
author_sort |
Shabangu, Fannie Welcome |
title |
Clicking throughout the year : sperm whale clicks in relation to environmental conditions off the west coast of South Africa |
title_short |
Clicking throughout the year : sperm whale clicks in relation to environmental conditions off the west coast of South Africa |
title_full |
Clicking throughout the year : sperm whale clicks in relation to environmental conditions off the west coast of South Africa |
title_fullStr |
Clicking throughout the year : sperm whale clicks in relation to environmental conditions off the west coast of South Africa |
title_full_unstemmed |
Clicking throughout the year : sperm whale clicks in relation to environmental conditions off the west coast of South Africa |
title_sort |
clicking throughout the year : sperm whale clicks in relation to environmental conditions off the west coast of south africa |
publisher |
Inter Research |
publishDate |
2020 |
url |
http://hdl.handle.net/2263/79159 https://doi.org/10.3354/esr01089 |
genre |
Sperm whale |
genre_facet |
Sperm whale |
op_relation |
http://hdl.handle.net/2263/79159 Shabangu FW, Andrew RK (2020) Clicking throughout the year: sperm whale clicks in relation to environmental conditions off the west coast of South Africa. Endangered Species Research 43:475-494. https://doi.org/10.3354/esr01089. 1863-5407 (print) 1613-4796 (online) doi:10.3354/esr01089 |
op_rights |
© The authors 2020. Open Access under Creative Commons by Attribution Licence. |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.3354/esr01089 |
container_title |
Endangered Species Research |
container_volume |
43 |
container_start_page |
475 |
op_container_end_page |
494 |
_version_ |
1766208509653811200 |