SIZE‐CLASS SEGREGATION OF BOWHEAD WHALES DISCERNED THROUGH AERIAL STEREOPHOTOGRAMMETRY
A bstract Bowhead whales ( Balaena mysticetus ) summering in the eastern Beaufort Sea in 1983 were measured through aerial stereophotogrammetry. Photos were taken from a turbine Aerocommander 690 with wingtip‐mounted, calibrated 35‐mm cameras. Photos were measured on an analytical plotter with scale...
Published in: | Marine Mammal Science |
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Online Access: | http://dx.doi.org/10.1111/j.1748-7692.1987.tb00160.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1748-7692.1987.tb00160.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1748-7692.1987.tb00160.x |
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crwiley:10.1111/j.1748-7692.1987.tb00160.x 2024-04-21T07:57:48+00:00 SIZE‐CLASS SEGREGATION OF BOWHEAD WHALES DISCERNED THROUGH AERIAL STEREOPHOTOGRAMMETRY Cubbage, James C. Calambokidis, John 1987 http://dx.doi.org/10.1111/j.1748-7692.1987.tb00160.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1748-7692.1987.tb00160.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1748-7692.1987.tb00160.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Marine Mammal Science volume 3, issue 2, page 179-185 ISSN 0824-0469 1748-7692 Aquatic Science Ecology, Evolution, Behavior and Systematics journal-article 1987 crwiley https://doi.org/10.1111/j.1748-7692.1987.tb00160.x 2024-03-28T08:28:21Z A bstract Bowhead whales ( Balaena mysticetus ) summering in the eastern Beaufort Sea in 1983 were measured through aerial stereophotogrammetry. Photos were taken from a turbine Aerocommander 690 with wingtip‐mounted, calibrated 35‐mm cameras. Photos were measured on an analytical plotter with scale data provided by radar altimeter and focal length of the lenses. Coefficient of variation of known‐sized targets 12 m long was 1.7 percent ( n = 25). Potential duplicate photographs of whales were removed from consideration through an algorithm based on whale swim speed and elapsed time between sightings. Significant segregation by bowhead whale length was found between four broad regions ( P < 0.001, ANOVA, Chi square). Also an inverse correlation appeared between longitude and size of animals ( P < 0.001), with the larger animals occurring farther east. This unequivocal size‐class segregation confounds an accurate assessment of overall size‐class composition of the population as well as recent attempts to determine calving rate from aerial survey data. Article in Journal/Newspaper Balaena mysticetus Beaufort Sea bowhead whale Wiley Online Library Marine Mammal Science 3 2 179 185 |
institution |
Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
topic |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Aquatic Science Ecology, Evolution, Behavior and Systematics Cubbage, James C. Calambokidis, John SIZE‐CLASS SEGREGATION OF BOWHEAD WHALES DISCERNED THROUGH AERIAL STEREOPHOTOGRAMMETRY |
topic_facet |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
description |
A bstract Bowhead whales ( Balaena mysticetus ) summering in the eastern Beaufort Sea in 1983 were measured through aerial stereophotogrammetry. Photos were taken from a turbine Aerocommander 690 with wingtip‐mounted, calibrated 35‐mm cameras. Photos were measured on an analytical plotter with scale data provided by radar altimeter and focal length of the lenses. Coefficient of variation of known‐sized targets 12 m long was 1.7 percent ( n = 25). Potential duplicate photographs of whales were removed from consideration through an algorithm based on whale swim speed and elapsed time between sightings. Significant segregation by bowhead whale length was found between four broad regions ( P < 0.001, ANOVA, Chi square). Also an inverse correlation appeared between longitude and size of animals ( P < 0.001), with the larger animals occurring farther east. This unequivocal size‐class segregation confounds an accurate assessment of overall size‐class composition of the population as well as recent attempts to determine calving rate from aerial survey data. |
format |
Article in Journal/Newspaper |
author |
Cubbage, James C. Calambokidis, John |
author_facet |
Cubbage, James C. Calambokidis, John |
author_sort |
Cubbage, James C. |
title |
SIZE‐CLASS SEGREGATION OF BOWHEAD WHALES DISCERNED THROUGH AERIAL STEREOPHOTOGRAMMETRY |
title_short |
SIZE‐CLASS SEGREGATION OF BOWHEAD WHALES DISCERNED THROUGH AERIAL STEREOPHOTOGRAMMETRY |
title_full |
SIZE‐CLASS SEGREGATION OF BOWHEAD WHALES DISCERNED THROUGH AERIAL STEREOPHOTOGRAMMETRY |
title_fullStr |
SIZE‐CLASS SEGREGATION OF BOWHEAD WHALES DISCERNED THROUGH AERIAL STEREOPHOTOGRAMMETRY |
title_full_unstemmed |
SIZE‐CLASS SEGREGATION OF BOWHEAD WHALES DISCERNED THROUGH AERIAL STEREOPHOTOGRAMMETRY |
title_sort |
size‐class segregation of bowhead whales discerned through aerial stereophotogrammetry |
publisher |
Wiley |
publishDate |
1987 |
url |
http://dx.doi.org/10.1111/j.1748-7692.1987.tb00160.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1748-7692.1987.tb00160.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1748-7692.1987.tb00160.x |
genre |
Balaena mysticetus Beaufort Sea bowhead whale |
genre_facet |
Balaena mysticetus Beaufort Sea bowhead whale |
op_source |
Marine Mammal Science volume 3, issue 2, page 179-185 ISSN 0824-0469 1748-7692 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1748-7692.1987.tb00160.x |
container_title |
Marine Mammal Science |
container_volume |
3 |
container_issue |
2 |
container_start_page |
179 |
op_container_end_page |
185 |
_version_ |
1796939265588854784 |