Annual Variation in Great Skua Diets: The Importance of Commercial Fisheries and Predation on Seabirds Revealed by Combining Dietary Analyses
Abstract This study combines conventional dietary assessment with stable isotope techniques to describe Great Skua (Stercorarius skua) diet. Stable carbon and nitrogen isotope ratios in feathers of Great Skua chicks collected over three years were analyzed in conjunction with pellet and regurgitate...
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Oxford University Press (OUP)
2001
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Online Access: | http://dx.doi.org/10.1093/condor/103.4.802 http://academic.oup.com/condor/article-pdf/103/4/802/29711085/condor0802.pdf |
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croxfordunivpr:10.1093/condor/103.4.802 2024-06-23T07:53:06+00:00 Annual Variation in Great Skua Diets: The Importance of Commercial Fisheries and Predation on Seabirds Revealed by Combining Dietary Analyses Bearhop, Stuart Thompson, David R. Phillips, Richard A. Waldron, Susan Hamer, Keith C. Gray, Catherine M. Votier, Stephen C. Ross, Ben P. Furness, Robert W. 2001 http://dx.doi.org/10.1093/condor/103.4.802 http://academic.oup.com/condor/article-pdf/103/4/802/29711085/condor0802.pdf en eng Oxford University Press (OUP) The Condor volume 103, issue 4, page 802-809 ISSN 0010-5422 1938-5129 journal-article 2001 croxfordunivpr https://doi.org/10.1093/condor/103.4.802 2024-06-04T06:08:24Z Abstract This study combines conventional dietary assessment with stable isotope techniques to describe Great Skua (Stercorarius skua) diet. Stable carbon and nitrogen isotope ratios in feathers of Great Skua chicks collected over three years were analyzed in conjunction with pellet and regurgitate collections. A significant drop in trophic status was detected in 1997, which likely resulted from an increase in herring and mackerel in the diet. These items were almost certainly obtained from a commercial trawler, as evidenced by a significant drop in territorial attendance during the ship's absence. Feathers yielded significantly different δ13C values among years, and part of this may have been related to a period of enhanced phytoplankton growth during 1996. A combined approach, such as the one described here, is likely to become increasingly useful in elucidating the diets of polyphagous birds. Variación Anual en la Dieta de Stercorarius skua: La Importancia de Pesqueros Comerciales y Predación de Aves Marinas Revelada por la Combinación de Análisis de Dieta Resumen. Este estudio combina evaluaciones de dieta convencionales con técnicas de isótopos estables para describir la dieta de Stercorarius skua. Analizamos la proporción de isótopos estables de carbono y nitrógeno en las plumas de pichones de S. skua colectadas durante más de tres años, en conjunto con colecciones de pellets y regurjitados. Un descenso significativo en la posición trófica fue detectado en 1997 probablemente como consecuencia del incremento de arenque y caballa en la dieta. Estos ítems fueron casi con seguridad obtenidos de un pesquero de arrastre comercial, como lo sugiere la caída significativa de la presencia en el territorio durante la ausencia del barco. Las plumas generaron valores significativamente diferentes de δ13C entre años, parte de lo cual puede haber estado relacionado con un período de gran crecimiento del fitoplancton durante 1996. Un enfoque combinado como el descripto aquí será probablemente cada vez más útil para ... Article in Journal/Newspaper Great skua Stercorarius skua Oxford University Press Consecuencia ENVELOPE(-60.783,-60.783,-63.717,-63.717) The Condor 103 4 802 809 |
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Oxford University Press |
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croxfordunivpr |
language |
English |
description |
Abstract This study combines conventional dietary assessment with stable isotope techniques to describe Great Skua (Stercorarius skua) diet. Stable carbon and nitrogen isotope ratios in feathers of Great Skua chicks collected over three years were analyzed in conjunction with pellet and regurgitate collections. A significant drop in trophic status was detected in 1997, which likely resulted from an increase in herring and mackerel in the diet. These items were almost certainly obtained from a commercial trawler, as evidenced by a significant drop in territorial attendance during the ship's absence. Feathers yielded significantly different δ13C values among years, and part of this may have been related to a period of enhanced phytoplankton growth during 1996. A combined approach, such as the one described here, is likely to become increasingly useful in elucidating the diets of polyphagous birds. Variación Anual en la Dieta de Stercorarius skua: La Importancia de Pesqueros Comerciales y Predación de Aves Marinas Revelada por la Combinación de Análisis de Dieta Resumen. Este estudio combina evaluaciones de dieta convencionales con técnicas de isótopos estables para describir la dieta de Stercorarius skua. Analizamos la proporción de isótopos estables de carbono y nitrógeno en las plumas de pichones de S. skua colectadas durante más de tres años, en conjunto con colecciones de pellets y regurjitados. Un descenso significativo en la posición trófica fue detectado en 1997 probablemente como consecuencia del incremento de arenque y caballa en la dieta. Estos ítems fueron casi con seguridad obtenidos de un pesquero de arrastre comercial, como lo sugiere la caída significativa de la presencia en el territorio durante la ausencia del barco. Las plumas generaron valores significativamente diferentes de δ13C entre años, parte de lo cual puede haber estado relacionado con un período de gran crecimiento del fitoplancton durante 1996. Un enfoque combinado como el descripto aquí será probablemente cada vez más útil para ... |
format |
Article in Journal/Newspaper |
author |
Bearhop, Stuart Thompson, David R. Phillips, Richard A. Waldron, Susan Hamer, Keith C. Gray, Catherine M. Votier, Stephen C. Ross, Ben P. Furness, Robert W. |
spellingShingle |
Bearhop, Stuart Thompson, David R. Phillips, Richard A. Waldron, Susan Hamer, Keith C. Gray, Catherine M. Votier, Stephen C. Ross, Ben P. Furness, Robert W. Annual Variation in Great Skua Diets: The Importance of Commercial Fisheries and Predation on Seabirds Revealed by Combining Dietary Analyses |
author_facet |
Bearhop, Stuart Thompson, David R. Phillips, Richard A. Waldron, Susan Hamer, Keith C. Gray, Catherine M. Votier, Stephen C. Ross, Ben P. Furness, Robert W. |
author_sort |
Bearhop, Stuart |
title |
Annual Variation in Great Skua Diets: The Importance of Commercial Fisheries and Predation on Seabirds Revealed by Combining Dietary Analyses |
title_short |
Annual Variation in Great Skua Diets: The Importance of Commercial Fisheries and Predation on Seabirds Revealed by Combining Dietary Analyses |
title_full |
Annual Variation in Great Skua Diets: The Importance of Commercial Fisheries and Predation on Seabirds Revealed by Combining Dietary Analyses |
title_fullStr |
Annual Variation in Great Skua Diets: The Importance of Commercial Fisheries and Predation on Seabirds Revealed by Combining Dietary Analyses |
title_full_unstemmed |
Annual Variation in Great Skua Diets: The Importance of Commercial Fisheries and Predation on Seabirds Revealed by Combining Dietary Analyses |
title_sort |
annual variation in great skua diets: the importance of commercial fisheries and predation on seabirds revealed by combining dietary analyses |
publisher |
Oxford University Press (OUP) |
publishDate |
2001 |
url |
http://dx.doi.org/10.1093/condor/103.4.802 http://academic.oup.com/condor/article-pdf/103/4/802/29711085/condor0802.pdf |
long_lat |
ENVELOPE(-60.783,-60.783,-63.717,-63.717) |
geographic |
Consecuencia |
geographic_facet |
Consecuencia |
genre |
Great skua Stercorarius skua |
genre_facet |
Great skua Stercorarius skua |
op_source |
The Condor volume 103, issue 4, page 802-809 ISSN 0010-5422 1938-5129 |
op_doi |
https://doi.org/10.1093/condor/103.4.802 |
container_title |
The Condor |
container_volume |
103 |
container_issue |
4 |
container_start_page |
802 |
op_container_end_page |
809 |
_version_ |
1802644596321157120 |