BLUE WHALE VISUAL AND ACOUSTIC ENCOUNTER RATES IN THE SOUTHERN CALIFORNIA BIGHT
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 withi...
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ftunivnebraskali:oai:digitalcommons.unl.edu:usdeptcommercepub-1298 2023-11-12T04:14:53+01:00 BLUE WHALE VISUAL AND ACOUSTIC ENCOUNTER RATES IN THE SOUTHERN CALIFORNIA BIGHT Oleson, Erin M. Calambokidis, John Barlow, Jay Hildebrand, John A. 2007-01-01T08:00:00Z application/pdf https://digitalcommons.unl.edu/usdeptcommercepub/299 https://digitalcommons.unl.edu/context/usdeptcommercepub/article/1298/viewcontent/Oleson_MMS_2007_Blue_whale_visual.pdf unknown DigitalCommons@University of Nebraska - Lincoln https://digitalcommons.unl.edu/usdeptcommercepub/299 https://digitalcommons.unl.edu/context/usdeptcommercepub/article/1298/viewcontent/Oleson_MMS_2007_Blue_whale_visual.pdf Publications, Agencies and Staff of the U.S. Department of Commerce blue whale Balaenoptera musculus visual survey acoustic survey encounter rate feeding ground Environmental Sciences text 2007 ftunivnebraskali 2023-10-30T09:45:21Z 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. Text Balaenoptera musculus Blue whale University of Nebraska-Lincoln: DigitalCommons@UNL |
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Open Polar |
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University of Nebraska-Lincoln: DigitalCommons@UNL |
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ftunivnebraskali |
language |
unknown |
topic |
blue whale Balaenoptera musculus visual survey acoustic survey encounter rate feeding ground Environmental Sciences |
spellingShingle |
blue whale Balaenoptera musculus visual survey acoustic survey encounter rate feeding ground Environmental Sciences Oleson, Erin M. Calambokidis, John Barlow, Jay Hildebrand, John A. BLUE WHALE VISUAL AND ACOUSTIC ENCOUNTER RATES IN THE SOUTHERN CALIFORNIA BIGHT |
topic_facet |
blue whale Balaenoptera musculus visual survey acoustic survey encounter rate feeding ground Environmental Sciences |
description |
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 |
Text |
author |
Oleson, Erin M. Calambokidis, John Barlow, Jay Hildebrand, John A. |
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 |
DigitalCommons@University of Nebraska - Lincoln |
publishDate |
2007 |
url |
https://digitalcommons.unl.edu/usdeptcommercepub/299 https://digitalcommons.unl.edu/context/usdeptcommercepub/article/1298/viewcontent/Oleson_MMS_2007_Blue_whale_visual.pdf |
genre |
Balaenoptera musculus Blue whale |
genre_facet |
Balaenoptera musculus Blue whale |
op_source |
Publications, Agencies and Staff of the U.S. Department of Commerce |
op_relation |
https://digitalcommons.unl.edu/usdeptcommercepub/299 https://digitalcommons.unl.edu/context/usdeptcommercepub/article/1298/viewcontent/Oleson_MMS_2007_Blue_whale_visual.pdf |
_version_ |
1782332404164198400 |