BLUE WHALE VISUAL AND ACOUSTIC ENCOUNTER RATES IN THE SOUTHERN CALIFORNIA BIGHT
Abstract The relationship between blue whale ( Balaenoptera musculus ) visual and acoustic encounter rates was quantitatively evaluated using hourly counts of detected whales during shipboard surveys off southern California. Encounter rates were estimated using temporal, geographic, and weather vari...
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crwiley:10.1111/j.1748-7692.2007.02303.x 2024-09-15T17:57:18+00:00 BLUE WHALE VISUAL AND ACOUSTIC ENCOUNTER RATES IN THE SOUTHERN CALIFORNIA BIGHT Oleson, Erin M. Calambokidis, John Barlow, Jay Hildebrand, John A. 2007 http://dx.doi.org/10.1111/j.1748-7692.2007.02303.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1748-7692.2007.02303.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1748-7692.2007.02303.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Marine Mammal Science volume 23, issue 3, page 574-597 ISSN 0824-0469 1748-7692 journal-article 2007 crwiley https://doi.org/10.1111/j.1748-7692.2007.02303.x 2024-07-23T04:12:11Z Abstract The relationship between blue whale ( Balaenoptera musculus ) visual and acoustic encounter rates was quantitatively evaluated using hourly counts of detected whales during shipboard surveys off southern California. Encounter rates were estimated using temporal, geographic, and weather variables within a generalized additive model framework. Visual encounters (2.06 animals/h, CV = 0.10) varied with subregion, Julian day, time of day, and year. Acoustic encounters of whales producing pulsed A and tonal B call sequences (song; 0.65 animals/h, CV = 0.06) varied by Julian day, survey mode (transit or stationary), and subregion, and encounters of whales producing downswept (D) calls (0.41 animals/h, CV = 0.09) varied by Julian day and the number of animals seen. Inclusion of Julian day in all models reflects the seasonal occurrence of blue whales off southern California; however, the seasonal peak in visual encounters and acoustic encounters of D calling whales (July–August) was offset from the peak in acoustic encounters of singing whales (August–September). The relationship between visual and acoustic encounter rates varied regionally, with significant differences in several northern regions. The number of whales heard D calling was positively related to the number of animals seen, whereas the number of singing whales was not related to visual encounter rate. Article in Journal/Newspaper Balaenoptera musculus Blue whale Wiley Online Library Marine Mammal Science 23 3 574 597 |
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Wiley Online Library |
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language |
English |
description |
Abstract The relationship between blue whale ( Balaenoptera musculus ) visual and acoustic encounter rates was quantitatively evaluated using hourly counts of detected whales during shipboard surveys off southern California. Encounter rates were estimated using temporal, geographic, and weather variables within a generalized additive model framework. Visual encounters (2.06 animals/h, CV = 0.10) varied with subregion, Julian day, time of day, and year. Acoustic encounters of whales producing pulsed A and tonal B call sequences (song; 0.65 animals/h, CV = 0.06) varied by Julian day, survey mode (transit or stationary), and subregion, and encounters of whales producing downswept (D) calls (0.41 animals/h, CV = 0.09) varied by Julian day and the number of animals seen. Inclusion of Julian day in all models reflects the seasonal occurrence of blue whales off southern California; however, the seasonal peak in visual encounters and acoustic encounters of D calling whales (July–August) was offset from the peak in acoustic encounters of singing whales (August–September). The relationship between visual and acoustic encounter rates varied regionally, with significant differences in several northern regions. The number of whales heard D calling was positively related to the number of animals seen, whereas the number of singing whales was not related to visual encounter rate. |
format |
Article in Journal/Newspaper |
author |
Oleson, Erin M. Calambokidis, John Barlow, Jay Hildebrand, John A. |
spellingShingle |
Oleson, Erin M. Calambokidis, John Barlow, Jay Hildebrand, John A. BLUE WHALE VISUAL AND ACOUSTIC ENCOUNTER RATES IN THE SOUTHERN CALIFORNIA BIGHT |
author_facet |
Oleson, Erin M. Calambokidis, John Barlow, Jay Hildebrand, John A. |
author_sort |
Oleson, Erin M. |
title |
BLUE WHALE VISUAL AND ACOUSTIC ENCOUNTER RATES IN THE SOUTHERN CALIFORNIA BIGHT |
title_short |
BLUE WHALE VISUAL AND ACOUSTIC ENCOUNTER RATES IN THE SOUTHERN CALIFORNIA BIGHT |
title_full |
BLUE WHALE VISUAL AND ACOUSTIC ENCOUNTER RATES IN THE SOUTHERN CALIFORNIA BIGHT |
title_fullStr |
BLUE WHALE VISUAL AND ACOUSTIC ENCOUNTER RATES IN THE SOUTHERN CALIFORNIA BIGHT |
title_full_unstemmed |
BLUE WHALE VISUAL AND ACOUSTIC ENCOUNTER RATES IN THE SOUTHERN CALIFORNIA BIGHT |
title_sort |
blue whale visual and acoustic encounter rates in the southern california bight |
publisher |
Wiley |
publishDate |
2007 |
url |
http://dx.doi.org/10.1111/j.1748-7692.2007.02303.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1748-7692.2007.02303.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1748-7692.2007.02303.x |
genre |
Balaenoptera musculus Blue whale |
genre_facet |
Balaenoptera musculus Blue whale |
op_source |
Marine Mammal Science volume 23, issue 3, page 574-597 ISSN 0824-0469 1748-7692 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1748-7692.2007.02303.x |
container_title |
Marine Mammal Science |
container_volume |
23 |
container_issue |
3 |
container_start_page |
574 |
op_container_end_page |
597 |
_version_ |
1810433455860744192 |