Intra‐ and inter‐annual variation in gray whale body condition on a foraging ground
Abstract Baleen whales store energy gained on foraging grounds to support reproduction and other metabolic needs while fasting for long periods during migration. Whale body condition can be used to monitor foraging success, and thus better understand and anticipate individual‐ and population‐level t...
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crwiley:10.1002/ecs2.3094 2024-06-02T08:04:03+00:00 Intra‐ and inter‐annual variation in gray whale body condition on a foraging ground Soledade Lemos, Leila Burnett, Jonathan D. Chandler, Todd E. Sumich, James L. Torres, Leigh G. Oregon Sea Grant, Oregon State University National Oceanic and Atmospheric Administration Conselho Nacional de Desenvolvimento Científico e Tecnológico 2020 http://dx.doi.org/10.1002/ecs2.3094 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fecs2.3094 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ecs2.3094 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/ecs2.3094 https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1002/ecs2.3094 en eng Wiley http://creativecommons.org/licenses/by/3.0/ http://creativecommons.org/licenses/by/3.0/ Ecosphere volume 11, issue 4 ISSN 2150-8925 2150-8925 journal-article 2020 crwiley https://doi.org/10.1002/ecs2.3094 2024-05-03T12:05:01Z Abstract Baleen whales store energy gained on foraging grounds to support reproduction and other metabolic needs while fasting for long periods during migration. Whale body condition can be used to monitor foraging success, and thus better understand and anticipate individual‐ and population‐level trends in reproduction and survival. We assessed the body condition of eastern North Pacific gray whales ( Eschrichtius robustus ) on their foraging grounds along the Oregon coast, USA, from June to October of three consecutive years (2016–2018). We used drone photogrammetry and applied the body area index (BAI) to measure and compare whale body condition, which is a continuous, unitless metric similar to the body mass index in humans. A total of 289 drone flights were carried out over 106 photo‐identified whales, which were grouped into demographic units by sex, maturity, and female reproductive status. Calves and pregnant females displayed the highest BAIs, followed by resting females, mature males, and, finally, lactating females, reflecting the significant energetic demands on reproductive females. In all three years, gray whale body condition improved with the progression of feeding seasons, demonstrating the accumulation of body energy reserves on the foraging grounds. Yet, body condition was significantly better in 2016 than in 2017 and 2018 when overall body depletion was observed, indicating a difference in prey availability and/or quality between years. We analyzed local upwelling patterns between 2013 and 2018 as an oceanographic proxy for prey and determined significantly greater upwelling between 2013 and 2015 than low upwelling years between 2016 and 2018. We hypothesize that these upwelling patterns created ecosystem shifts in primary productivity and zooplankton prey of gray whales, causing carry‐over effects between foraging success and body condition in subsequent years. This study demonstrates the value of monitoring whale body condition to better understand temporal variation in foraging success, ... Article in Journal/Newspaper baleen whales Wiley Online Library Pacific Ecosphere 11 4 |
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Open Polar |
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Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract Baleen whales store energy gained on foraging grounds to support reproduction and other metabolic needs while fasting for long periods during migration. Whale body condition can be used to monitor foraging success, and thus better understand and anticipate individual‐ and population‐level trends in reproduction and survival. We assessed the body condition of eastern North Pacific gray whales ( Eschrichtius robustus ) on their foraging grounds along the Oregon coast, USA, from June to October of three consecutive years (2016–2018). We used drone photogrammetry and applied the body area index (BAI) to measure and compare whale body condition, which is a continuous, unitless metric similar to the body mass index in humans. A total of 289 drone flights were carried out over 106 photo‐identified whales, which were grouped into demographic units by sex, maturity, and female reproductive status. Calves and pregnant females displayed the highest BAIs, followed by resting females, mature males, and, finally, lactating females, reflecting the significant energetic demands on reproductive females. In all three years, gray whale body condition improved with the progression of feeding seasons, demonstrating the accumulation of body energy reserves on the foraging grounds. Yet, body condition was significantly better in 2016 than in 2017 and 2018 when overall body depletion was observed, indicating a difference in prey availability and/or quality between years. We analyzed local upwelling patterns between 2013 and 2018 as an oceanographic proxy for prey and determined significantly greater upwelling between 2013 and 2015 than low upwelling years between 2016 and 2018. We hypothesize that these upwelling patterns created ecosystem shifts in primary productivity and zooplankton prey of gray whales, causing carry‐over effects between foraging success and body condition in subsequent years. This study demonstrates the value of monitoring whale body condition to better understand temporal variation in foraging success, ... |
author2 |
Oregon Sea Grant, Oregon State University National Oceanic and Atmospheric Administration Conselho Nacional de Desenvolvimento Científico e Tecnológico |
format |
Article in Journal/Newspaper |
author |
Soledade Lemos, Leila Burnett, Jonathan D. Chandler, Todd E. Sumich, James L. Torres, Leigh G. |
spellingShingle |
Soledade Lemos, Leila Burnett, Jonathan D. Chandler, Todd E. Sumich, James L. Torres, Leigh G. Intra‐ and inter‐annual variation in gray whale body condition on a foraging ground |
author_facet |
Soledade Lemos, Leila Burnett, Jonathan D. Chandler, Todd E. Sumich, James L. Torres, Leigh G. |
author_sort |
Soledade Lemos, Leila |
title |
Intra‐ and inter‐annual variation in gray whale body condition on a foraging ground |
title_short |
Intra‐ and inter‐annual variation in gray whale body condition on a foraging ground |
title_full |
Intra‐ and inter‐annual variation in gray whale body condition on a foraging ground |
title_fullStr |
Intra‐ and inter‐annual variation in gray whale body condition on a foraging ground |
title_full_unstemmed |
Intra‐ and inter‐annual variation in gray whale body condition on a foraging ground |
title_sort |
intra‐ and inter‐annual variation in gray whale body condition on a foraging ground |
publisher |
Wiley |
publishDate |
2020 |
url |
http://dx.doi.org/10.1002/ecs2.3094 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fecs2.3094 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ecs2.3094 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/ecs2.3094 https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1002/ecs2.3094 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
baleen whales |
genre_facet |
baleen whales |
op_source |
Ecosphere volume 11, issue 4 ISSN 2150-8925 2150-8925 |
op_rights |
http://creativecommons.org/licenses/by/3.0/ http://creativecommons.org/licenses/by/3.0/ |
op_doi |
https://doi.org/10.1002/ecs2.3094 |
container_title |
Ecosphere |
container_volume |
11 |
container_issue |
4 |
_version_ |
1800748679053705216 |