Long-term feeding ecology of Great Black-backed Gulls (Larus marinus) in the northwest Atlantic: 110 years of feather isotope data
Recent changes to the ecology of the northwest Atlantic are affecting feeding relationships at many trophic levels. With declining fish stocks and fewer fisheries discards, generalist birds such as Great Black-backed Gulls ( Larus marinus L., 1758) may shift their diets. To test whether such a chang...
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Online Access: | http://dx.doi.org/10.1139/z10-102 http://www.nrcresearchpress.com/doi/full-xml/10.1139/Z10-102 http://www.nrcresearchpress.com/doi/pdf/10.1139/Z10-102 |
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crcansciencepubl:10.1139/z10-102 2023-12-17T10:47:36+01:00 Long-term feeding ecology of Great Black-backed Gulls (Larus marinus) in the northwest Atlantic: 110 years of feather isotope data Farmer, R. G. Leonard, M. L. 2011 http://dx.doi.org/10.1139/z10-102 http://www.nrcresearchpress.com/doi/full-xml/10.1139/Z10-102 http://www.nrcresearchpress.com/doi/pdf/10.1139/Z10-102 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Zoology volume 89, issue 2, page 123-133 ISSN 0008-4301 1480-3283 Animal Science and Zoology Ecology, Evolution, Behavior and Systematics journal-article 2011 crcansciencepubl https://doi.org/10.1139/z10-102 2023-11-19T13:38:56Z Recent changes to the ecology of the northwest Atlantic are affecting feeding relationships at many trophic levels. With declining fish stocks and fewer fisheries discards, generalist birds such as Great Black-backed Gulls ( Larus marinus L., 1758) may shift their diets. To test whether such a change has occurred, we measured stable nitrogen and carbon isotope ratios of flight feathers collected from modern and museum-preserved birds (1896–2006). We then compared trends in isotope ratios with trends in regional fisheries productivity to determine if gull diets and fisheries changes were associated. We found a significant decline in stable nitrogen isotope ratios of feathers over time, indicating that the gulls’ trophic feeding level has decreased by approximately 2.26‰, or 0.82 trophic units. In contrast, we found no significant change in carbon isotope ratios, giving no clear evidence for a shift to more offshore or terrestrial foraging. The declining stable nitrogen ratio was significantly and positively correlated with both regional groundfish captures and regional fisheries trophic level, and was negatively correlated with each of (i) crab captures and (ii) herring, sardine, and anchovy captures. Our study gives evidence for a shift in diets of Great Black-backed Gulls over time and further suggests that these changes may be related to ongoing changes in fisheries. Article in Journal/Newspaper Northwest Atlantic Canadian Science Publishing (via Crossref) Canadian Journal of Zoology 89 2 123 133 |
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Open Polar |
collection |
Canadian Science Publishing (via Crossref) |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics Farmer, R. G. Leonard, M. L. Long-term feeding ecology of Great Black-backed Gulls (Larus marinus) in the northwest Atlantic: 110 years of feather isotope data |
topic_facet |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics |
description |
Recent changes to the ecology of the northwest Atlantic are affecting feeding relationships at many trophic levels. With declining fish stocks and fewer fisheries discards, generalist birds such as Great Black-backed Gulls ( Larus marinus L., 1758) may shift their diets. To test whether such a change has occurred, we measured stable nitrogen and carbon isotope ratios of flight feathers collected from modern and museum-preserved birds (1896–2006). We then compared trends in isotope ratios with trends in regional fisheries productivity to determine if gull diets and fisheries changes were associated. We found a significant decline in stable nitrogen isotope ratios of feathers over time, indicating that the gulls’ trophic feeding level has decreased by approximately 2.26‰, or 0.82 trophic units. In contrast, we found no significant change in carbon isotope ratios, giving no clear evidence for a shift to more offshore or terrestrial foraging. The declining stable nitrogen ratio was significantly and positively correlated with both regional groundfish captures and regional fisheries trophic level, and was negatively correlated with each of (i) crab captures and (ii) herring, sardine, and anchovy captures. Our study gives evidence for a shift in diets of Great Black-backed Gulls over time and further suggests that these changes may be related to ongoing changes in fisheries. |
format |
Article in Journal/Newspaper |
author |
Farmer, R. G. Leonard, M. L. |
author_facet |
Farmer, R. G. Leonard, M. L. |
author_sort |
Farmer, R. G. |
title |
Long-term feeding ecology of Great Black-backed Gulls (Larus marinus) in the northwest Atlantic: 110 years of feather isotope data |
title_short |
Long-term feeding ecology of Great Black-backed Gulls (Larus marinus) in the northwest Atlantic: 110 years of feather isotope data |
title_full |
Long-term feeding ecology of Great Black-backed Gulls (Larus marinus) in the northwest Atlantic: 110 years of feather isotope data |
title_fullStr |
Long-term feeding ecology of Great Black-backed Gulls (Larus marinus) in the northwest Atlantic: 110 years of feather isotope data |
title_full_unstemmed |
Long-term feeding ecology of Great Black-backed Gulls (Larus marinus) in the northwest Atlantic: 110 years of feather isotope data |
title_sort |
long-term feeding ecology of great black-backed gulls (larus marinus) in the northwest atlantic: 110 years of feather isotope data |
publisher |
Canadian Science Publishing |
publishDate |
2011 |
url |
http://dx.doi.org/10.1139/z10-102 http://www.nrcresearchpress.com/doi/full-xml/10.1139/Z10-102 http://www.nrcresearchpress.com/doi/pdf/10.1139/Z10-102 |
genre |
Northwest Atlantic |
genre_facet |
Northwest Atlantic |
op_source |
Canadian Journal of Zoology volume 89, issue 2, page 123-133 ISSN 0008-4301 1480-3283 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/z10-102 |
container_title |
Canadian Journal of Zoology |
container_volume |
89 |
container_issue |
2 |
container_start_page |
123 |
op_container_end_page |
133 |
_version_ |
1785571493647745024 |