Diurnal increases in depths of humpback whale ( Megaptera novaeangliae) mother‐calf pods off West Maui, Hawaiʻi: A response to vessels?
Abstract Studies of humpback whale ( Megaptera novaeangliae ) habitat use in their Hawaiian breeding grounds have revealed that mother‐calf pairs favor shallow waters to avoid harassment from males. However, human activity in these same waters may exert an opposing force on habitat use. To investiga...
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Online Access: | http://dx.doi.org/10.1111/mms.12926 https://onlinelibrary.wiley.com/doi/pdf/10.1111/mms.12926 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/mms.12926 |
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crwiley:10.1111/mms.12926 2024-06-23T07:53:35+00:00 Diurnal increases in depths of humpback whale ( Megaptera novaeangliae) mother‐calf pods off West Maui, Hawaiʻi: A response to vessels? Pack, Adam A. Waterman, James O. Craig, Alison S. 2022 http://dx.doi.org/10.1111/mms.12926 https://onlinelibrary.wiley.com/doi/pdf/10.1111/mms.12926 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/mms.12926 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Marine Mammal Science volume 38, issue 4, page 1340-1356 ISSN 0824-0469 1748-7692 journal-article 2022 crwiley https://doi.org/10.1111/mms.12926 2024-06-04T06:41:43Z Abstract Studies of humpback whale ( Megaptera novaeangliae ) habitat use in their Hawaiian breeding grounds have revealed that mother‐calf pairs favor shallow waters to avoid harassment from males. However, human activity in these same waters may exert an opposing force on habitat use. To investigate this hypothesis, instantaneous scan samples of whale and vessel distribution were collected from West Maui, Hawaiʻi. Theodolite position fixes were combined with GIS techniques to determine the depths and seabed terrain type occupied by 161 humpback whale pods containing a calf (calf pods) and 872 pods without a calf (noncalf pods). We found no significant diurnal trends for noncalf pods, but calf pods occupied progressively deeper water over the course of each day. There was no evidence that this shift was related to (1) a “spillover” resulting from high mother‐calf density in shallow water, (2) harassment by males occupying the same space as mother‐calf pairs, or (3) the presence of mainly older and larger calves. However, while diurnal trends of whale‐watching vessels largely mirrored those of mother‐calf pods, nonwhale‐watching vessels tended to remain in shallower waters throughout the day. These results suggest that nearshore vessels may negatively impact the natural preference of mother‐calf pairs for shallow waters. Article in Journal/Newspaper Humpback Whale Megaptera novaeangliae Wiley Online Library Marine Mammal Science |
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Wiley Online Library |
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English |
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Abstract Studies of humpback whale ( Megaptera novaeangliae ) habitat use in their Hawaiian breeding grounds have revealed that mother‐calf pairs favor shallow waters to avoid harassment from males. However, human activity in these same waters may exert an opposing force on habitat use. To investigate this hypothesis, instantaneous scan samples of whale and vessel distribution were collected from West Maui, Hawaiʻi. Theodolite position fixes were combined with GIS techniques to determine the depths and seabed terrain type occupied by 161 humpback whale pods containing a calf (calf pods) and 872 pods without a calf (noncalf pods). We found no significant diurnal trends for noncalf pods, but calf pods occupied progressively deeper water over the course of each day. There was no evidence that this shift was related to (1) a “spillover” resulting from high mother‐calf density in shallow water, (2) harassment by males occupying the same space as mother‐calf pairs, or (3) the presence of mainly older and larger calves. However, while diurnal trends of whale‐watching vessels largely mirrored those of mother‐calf pods, nonwhale‐watching vessels tended to remain in shallower waters throughout the day. These results suggest that nearshore vessels may negatively impact the natural preference of mother‐calf pairs for shallow waters. |
format |
Article in Journal/Newspaper |
author |
Pack, Adam A. Waterman, James O. Craig, Alison S. |
spellingShingle |
Pack, Adam A. Waterman, James O. Craig, Alison S. Diurnal increases in depths of humpback whale ( Megaptera novaeangliae) mother‐calf pods off West Maui, Hawaiʻi: A response to vessels? |
author_facet |
Pack, Adam A. Waterman, James O. Craig, Alison S. |
author_sort |
Pack, Adam A. |
title |
Diurnal increases in depths of humpback whale ( Megaptera novaeangliae) mother‐calf pods off West Maui, Hawaiʻi: A response to vessels? |
title_short |
Diurnal increases in depths of humpback whale ( Megaptera novaeangliae) mother‐calf pods off West Maui, Hawaiʻi: A response to vessels? |
title_full |
Diurnal increases in depths of humpback whale ( Megaptera novaeangliae) mother‐calf pods off West Maui, Hawaiʻi: A response to vessels? |
title_fullStr |
Diurnal increases in depths of humpback whale ( Megaptera novaeangliae) mother‐calf pods off West Maui, Hawaiʻi: A response to vessels? |
title_full_unstemmed |
Diurnal increases in depths of humpback whale ( Megaptera novaeangliae) mother‐calf pods off West Maui, Hawaiʻi: A response to vessels? |
title_sort |
diurnal increases in depths of humpback whale ( megaptera novaeangliae) mother‐calf pods off west maui, hawaiʻi: a response to vessels? |
publisher |
Wiley |
publishDate |
2022 |
url |
http://dx.doi.org/10.1111/mms.12926 https://onlinelibrary.wiley.com/doi/pdf/10.1111/mms.12926 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/mms.12926 |
genre |
Humpback Whale Megaptera novaeangliae |
genre_facet |
Humpback Whale Megaptera novaeangliae |
op_source |
Marine Mammal Science volume 38, issue 4, page 1340-1356 ISSN 0824-0469 1748-7692 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/mms.12926 |
container_title |
Marine Mammal Science |
_version_ |
1802645313036484608 |