Morphometric study of humpback whale mother-calf pairs in the Sainte Marie channel, Madagascar, using a simple drone-based photogrammetric method
Morphometric studies of humpback whales (Megaptera novaeangliae) occurring in the Indian Ocean area have been limited by the technology currently available. In the Sainte Marie channel, Madagascar, straightforward aerial single-camera photogrammetry was tested on mother-calf pairs that combines stan...
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ftjafricanj:oai:ajol.info:article/209962 2023-05-15T16:36:04+02:00 Morphometric study of humpback whale mother-calf pairs in the Sainte Marie channel, Madagascar, using a simple drone-based photogrammetric method Ratsimbazafindranahaka, Maevatiana Razafimahatratra, Emilienne Mathevet, Robin Adam, Olivier Huetz, Chloé Charrier, Isabelle Saloma, Anjara 2022-02-02 application/pdf https://www.ajol.info/index.php/wiojms/article/view/209962 https://doi.org/10.4314/wiojms.v20i2.8 eng eng Western Indian Ocean Marine Science Association https://www.ajol.info/index.php/wiojms/article/view/209962/208301 https://www.ajol.info/index.php/wiojms/article/view/209962 doi:10.4314/wiojms.v20i2.8 Copyright (c) 2021 Western Indian Ocean Journal of Marine Science Western Indian Ocean Journal of Marine Science; Vol. 20 No. 2 (2021); 95-107 2683-6416 0856-860X aerial photogrammetry breeding grounds parity Unoccupied Aerial Vehicle (UAV) info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2022 ftjafricanj https://doi.org/10.4314/wiojms.v20i2.8 2022-09-18T00:25:35Z Morphometric studies of humpback whales (Megaptera novaeangliae) occurring in the Indian Ocean area have been limited by the technology currently available. In the Sainte Marie channel, Madagascar, straightforward aerial single-camera photogrammetry was tested on mother-calf pairs that combines standard Unoccupied Aerial Vehicle (UAV) with free, easy-to-access, and user-friendly software. The goals of the study were to estimate mother and calf body measurements and to investigate the effect of maternal parity (primiparous versus multiparous, based on length) on calf size. A mean length of 12.4±1.2 m for mothers (N = 16) and 5±0.9 m for calves (N = 16) was estimated. The size of calves did not depend significantly on maternal parity. The photogrammetry method used was simple and cost-effective, yet produced convincing morphometric measurements with acceptable precision and accuracy. The coefficients of variation (CVs) of repeated estimates and the level of error were relatively low (CV = 2.31 % for a known-sized object and average CV = 2.52 % for individual whales; average error = 1.8 % for a known-sized object). These results will encourage more teams to study the morphometry of large marine mammals despite limitations in terms of resources. Article in Journal/Newspaper Humpback Whale Megaptera novaeangliae AJOL - African Journals Online Indian Western Indian Ocean Journal of Marine Science 20 2 95 107 |
institution |
Open Polar |
collection |
AJOL - African Journals Online |
op_collection_id |
ftjafricanj |
language |
English |
topic |
aerial photogrammetry breeding grounds parity Unoccupied Aerial Vehicle (UAV) |
spellingShingle |
aerial photogrammetry breeding grounds parity Unoccupied Aerial Vehicle (UAV) Ratsimbazafindranahaka, Maevatiana Razafimahatratra, Emilienne Mathevet, Robin Adam, Olivier Huetz, Chloé Charrier, Isabelle Saloma, Anjara Morphometric study of humpback whale mother-calf pairs in the Sainte Marie channel, Madagascar, using a simple drone-based photogrammetric method |
topic_facet |
aerial photogrammetry breeding grounds parity Unoccupied Aerial Vehicle (UAV) |
description |
Morphometric studies of humpback whales (Megaptera novaeangliae) occurring in the Indian Ocean area have been limited by the technology currently available. In the Sainte Marie channel, Madagascar, straightforward aerial single-camera photogrammetry was tested on mother-calf pairs that combines standard Unoccupied Aerial Vehicle (UAV) with free, easy-to-access, and user-friendly software. The goals of the study were to estimate mother and calf body measurements and to investigate the effect of maternal parity (primiparous versus multiparous, based on length) on calf size. A mean length of 12.4±1.2 m for mothers (N = 16) and 5±0.9 m for calves (N = 16) was estimated. The size of calves did not depend significantly on maternal parity. The photogrammetry method used was simple and cost-effective, yet produced convincing morphometric measurements with acceptable precision and accuracy. The coefficients of variation (CVs) of repeated estimates and the level of error were relatively low (CV = 2.31 % for a known-sized object and average CV = 2.52 % for individual whales; average error = 1.8 % for a known-sized object). These results will encourage more teams to study the morphometry of large marine mammals despite limitations in terms of resources. |
format |
Article in Journal/Newspaper |
author |
Ratsimbazafindranahaka, Maevatiana Razafimahatratra, Emilienne Mathevet, Robin Adam, Olivier Huetz, Chloé Charrier, Isabelle Saloma, Anjara |
author_facet |
Ratsimbazafindranahaka, Maevatiana Razafimahatratra, Emilienne Mathevet, Robin Adam, Olivier Huetz, Chloé Charrier, Isabelle Saloma, Anjara |
author_sort |
Ratsimbazafindranahaka, Maevatiana |
title |
Morphometric study of humpback whale mother-calf pairs in the Sainte Marie channel, Madagascar, using a simple drone-based photogrammetric method |
title_short |
Morphometric study of humpback whale mother-calf pairs in the Sainte Marie channel, Madagascar, using a simple drone-based photogrammetric method |
title_full |
Morphometric study of humpback whale mother-calf pairs in the Sainte Marie channel, Madagascar, using a simple drone-based photogrammetric method |
title_fullStr |
Morphometric study of humpback whale mother-calf pairs in the Sainte Marie channel, Madagascar, using a simple drone-based photogrammetric method |
title_full_unstemmed |
Morphometric study of humpback whale mother-calf pairs in the Sainte Marie channel, Madagascar, using a simple drone-based photogrammetric method |
title_sort |
morphometric study of humpback whale mother-calf pairs in the sainte marie channel, madagascar, using a simple drone-based photogrammetric method |
publisher |
Western Indian Ocean Marine Science Association |
publishDate |
2022 |
url |
https://www.ajol.info/index.php/wiojms/article/view/209962 https://doi.org/10.4314/wiojms.v20i2.8 |
geographic |
Indian |
geographic_facet |
Indian |
genre |
Humpback Whale Megaptera novaeangliae |
genre_facet |
Humpback Whale Megaptera novaeangliae |
op_source |
Western Indian Ocean Journal of Marine Science; Vol. 20 No. 2 (2021); 95-107 2683-6416 0856-860X |
op_relation |
https://www.ajol.info/index.php/wiojms/article/view/209962/208301 https://www.ajol.info/index.php/wiojms/article/view/209962 doi:10.4314/wiojms.v20i2.8 |
op_rights |
Copyright (c) 2021 Western Indian Ocean Journal of Marine Science |
op_doi |
https://doi.org/10.4314/wiojms.v20i2.8 |
container_title |
Western Indian Ocean Journal of Marine Science |
container_volume |
20 |
container_issue |
2 |
container_start_page |
95 |
op_container_end_page |
107 |
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1766026377581035520 |