Description and classification of echolocation clicks of Indian Ocean humpback (Sousa plumbea) and Indo-Pacific bottlenose (Tursiops aduncus) dolphins from Menai Bay, Zanzibar, East Africa
Passive acoustic monitoring (PAM) is a powerful method to study the occurrence, movement and behavior of echolocating odontocetes (toothed whales) in the wild. However, in areas occupied by more than one species, echolocation clicks need to be classified into species. The present study investigated...
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ftzenodo:oai:zenodo.org:4975194 2024-09-15T18:39:13+00:00 Description and classification of echolocation clicks of Indian Ocean humpback (Sousa plumbea) and Indo-Pacific bottlenose (Tursiops aduncus) dolphins from Menai Bay, Zanzibar, East Africa Yang, Liangliang Sharpe, Matt Temple, Andrew Jiddawi, Narriman Xu, Xiaomei Berggren, Per 2020-03-10 https://doi.org/10.5061/dryad.zcrjdfn76 unknown Zenodo https://zenodo.org/communities/dryad https://doi.org/10.5061/dryad.zcrjdfn76 oai:zenodo.org:4975194 info:eu-repo/semantics/openAccess Creative Commons Zero v1.0 Universal https://creativecommons.org/publicdomain/zero/1.0/legalcode coastal Indian Ocean humpback dolphin Sousa plumbea Indo-Pacific bottlenose dolphin Tursiops aduncus Underwater sounds echolocation clicks info:eu-repo/semantics/other 2020 ftzenodo https://doi.org/10.5061/dryad.zcrjdfn76 2024-07-26T05:45:27Z Passive acoustic monitoring (PAM) is a powerful method to study the occurrence, movement and behavior of echolocating odontocetes (toothed whales) in the wild. However, in areas occupied by more than one species, echolocation clicks need to be classified into species. The present study investigated whether the echolocation clicks produced by small, at-risk, resident sympatric populations of Indian Ocean humpback dolphin (Sousa plumbea) and Indo-Pacific bottlenose dolphin (Tursiops aduncus) in Menai Bay, Zanzibar, East Africa, could be classified to allow species specific monitoring. Underwater sounds of S. plumbea and T. aduncus groups were recorded using a SoundTrap 202HF in January and June-August 2015. Eight acoustic parameters, i.e. -10 dB duration, peak, centroid, lower -3 and lower -10 dB frequencies, and -3 dB, -10 dB and root-mean-squared bandwidth, were used to describe and compare the two species' echolocation clicks. Statistical analyses showed that S. plumbea clicks had significantly higher peak, centroid, lower -3 and lower -10 dB frequencies compared to T. aduncus, whereas duration and bandwidth parameters were similar for the two species. Random Forest (RF) classifiers were applied to determine parameters that could be used to classify the two species from echolocation clicks and achieved 28.6% and 90.2% correct species classification rates for S. plumbea and T. aduncus, respectively. Both species were classified at a higher rate than expected at random, however the identified classifiers would only be useful for T. aduncus monitoring. The frequency and bandwidth parameters provided most power for species classification. Further study is necessary to identify useful classifiers for S. plumbea. This study represents a first step in acoustic description and classification of S. plumbea and T. aduncus in the western Indian Ocean region, with potential application for future acoustic monitoring of species-specific temporal and spatial occurrence in these sympatric species. Other/Unknown Material toothed whales Zenodo |
institution |
Open Polar |
collection |
Zenodo |
op_collection_id |
ftzenodo |
language |
unknown |
topic |
coastal Indian Ocean humpback dolphin Sousa plumbea Indo-Pacific bottlenose dolphin Tursiops aduncus Underwater sounds echolocation clicks |
spellingShingle |
coastal Indian Ocean humpback dolphin Sousa plumbea Indo-Pacific bottlenose dolphin Tursiops aduncus Underwater sounds echolocation clicks Yang, Liangliang Sharpe, Matt Temple, Andrew Jiddawi, Narriman Xu, Xiaomei Berggren, Per Description and classification of echolocation clicks of Indian Ocean humpback (Sousa plumbea) and Indo-Pacific bottlenose (Tursiops aduncus) dolphins from Menai Bay, Zanzibar, East Africa |
topic_facet |
coastal Indian Ocean humpback dolphin Sousa plumbea Indo-Pacific bottlenose dolphin Tursiops aduncus Underwater sounds echolocation clicks |
description |
Passive acoustic monitoring (PAM) is a powerful method to study the occurrence, movement and behavior of echolocating odontocetes (toothed whales) in the wild. However, in areas occupied by more than one species, echolocation clicks need to be classified into species. The present study investigated whether the echolocation clicks produced by small, at-risk, resident sympatric populations of Indian Ocean humpback dolphin (Sousa plumbea) and Indo-Pacific bottlenose dolphin (Tursiops aduncus) in Menai Bay, Zanzibar, East Africa, could be classified to allow species specific monitoring. Underwater sounds of S. plumbea and T. aduncus groups were recorded using a SoundTrap 202HF in January and June-August 2015. Eight acoustic parameters, i.e. -10 dB duration, peak, centroid, lower -3 and lower -10 dB frequencies, and -3 dB, -10 dB and root-mean-squared bandwidth, were used to describe and compare the two species' echolocation clicks. Statistical analyses showed that S. plumbea clicks had significantly higher peak, centroid, lower -3 and lower -10 dB frequencies compared to T. aduncus, whereas duration and bandwidth parameters were similar for the two species. Random Forest (RF) classifiers were applied to determine parameters that could be used to classify the two species from echolocation clicks and achieved 28.6% and 90.2% correct species classification rates for S. plumbea and T. aduncus, respectively. Both species were classified at a higher rate than expected at random, however the identified classifiers would only be useful for T. aduncus monitoring. The frequency and bandwidth parameters provided most power for species classification. Further study is necessary to identify useful classifiers for S. plumbea. This study represents a first step in acoustic description and classification of S. plumbea and T. aduncus in the western Indian Ocean region, with potential application for future acoustic monitoring of species-specific temporal and spatial occurrence in these sympatric species. |
format |
Other/Unknown Material |
author |
Yang, Liangliang Sharpe, Matt Temple, Andrew Jiddawi, Narriman Xu, Xiaomei Berggren, Per |
author_facet |
Yang, Liangliang Sharpe, Matt Temple, Andrew Jiddawi, Narriman Xu, Xiaomei Berggren, Per |
author_sort |
Yang, Liangliang |
title |
Description and classification of echolocation clicks of Indian Ocean humpback (Sousa plumbea) and Indo-Pacific bottlenose (Tursiops aduncus) dolphins from Menai Bay, Zanzibar, East Africa |
title_short |
Description and classification of echolocation clicks of Indian Ocean humpback (Sousa plumbea) and Indo-Pacific bottlenose (Tursiops aduncus) dolphins from Menai Bay, Zanzibar, East Africa |
title_full |
Description and classification of echolocation clicks of Indian Ocean humpback (Sousa plumbea) and Indo-Pacific bottlenose (Tursiops aduncus) dolphins from Menai Bay, Zanzibar, East Africa |
title_fullStr |
Description and classification of echolocation clicks of Indian Ocean humpback (Sousa plumbea) and Indo-Pacific bottlenose (Tursiops aduncus) dolphins from Menai Bay, Zanzibar, East Africa |
title_full_unstemmed |
Description and classification of echolocation clicks of Indian Ocean humpback (Sousa plumbea) and Indo-Pacific bottlenose (Tursiops aduncus) dolphins from Menai Bay, Zanzibar, East Africa |
title_sort |
description and classification of echolocation clicks of indian ocean humpback (sousa plumbea) and indo-pacific bottlenose (tursiops aduncus) dolphins from menai bay, zanzibar, east africa |
publisher |
Zenodo |
publishDate |
2020 |
url |
https://doi.org/10.5061/dryad.zcrjdfn76 |
genre |
toothed whales |
genre_facet |
toothed whales |
op_relation |
https://zenodo.org/communities/dryad https://doi.org/10.5061/dryad.zcrjdfn76 oai:zenodo.org:4975194 |
op_rights |
info:eu-repo/semantics/openAccess Creative Commons Zero v1.0 Universal https://creativecommons.org/publicdomain/zero/1.0/legalcode |
op_doi |
https://doi.org/10.5061/dryad.zcrjdfn76 |
_version_ |
1810483616504872960 |