Effects of experimentally increased egg production on female body condition and laying dates in the great skua Stercorarius skua
We investigated the effects of increased egg production on body condition as well as on measures of reproductive performance in great skuas, Stercorarius skua , over two subsequent years. We experimentally increased egg production from the normal two to six eggs. Six eggs might also be produced unde...
Published in: | Journal of Avian Biology |
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Online Access: | http://dx.doi.org/10.1111/j.0908-8857.2004.03271.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.0908-8857.2004.03271.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.0908-8857.2004.03271.x |
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crwiley:10.1111/j.0908-8857.2004.03271.x 2024-06-23T07:53:06+00:00 Effects of experimentally increased egg production on female body condition and laying dates in the great skua Stercorarius skua Kalmbach, Ellen Griffiths, Richard Crane, Jonathan E. Furness, Robert W. 2004 http://dx.doi.org/10.1111/j.0908-8857.2004.03271.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.0908-8857.2004.03271.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.0908-8857.2004.03271.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Journal of Avian Biology volume 35, issue 6, page 501-514 ISSN 0908-8857 1600-048X journal-article 2004 crwiley https://doi.org/10.1111/j.0908-8857.2004.03271.x 2024-05-31T08:15:08Z We investigated the effects of increased egg production on body condition as well as on measures of reproductive performance in great skuas, Stercorarius skua , over two subsequent years. We experimentally increased egg production from the normal two to six eggs. Six eggs might also be produced under natural circumstances after repeated clutch loss. After the production of the last egg we measured: (i) body mass, (ii) pectoral muscle, and (iii) haematocrit, total red blood cell count and mean corpuscular volume, as indicators of body condition. We took the same measurements of control females who had produced the normal clutch of two eggs. The measurements were repeated one year after the manipulation, and survival, laying dates, clutch sizes and hatching success were recorded for up to three consecutive years. After producing six eggs, females were lighter, had smaller pectoral muscles and lower haematological values than control females. Hatching success of eggs was significantly reduced. Even one year after the experiment there were still differences in body condition. Annual survival was not affected by the manipulations, although there was an indication that survival costs depended on whether chicks were raised after the increased egg production. While pair bonds and egg sizes were not affected in the post‐experimental year, females started breeding significantly later than in the previous year. Two years after the experiment laying dates had advanced again and were not different from those of control females. This pattern of maintaining survival and egg sizes, but delaying breeding in the post‐experimental year was found for two independent groups of females which had both been subjected to increased egg production. These results present evidence that increased egg production can have long‐term effects on female body condition and aspects of reproduction. However, although present, the costs of extra eggs appear to have been relatively small in the great skua in comparison to the two other bird species for ... Article in Journal/Newspaper Great skua Stercorarius skua Wiley Online Library Journal of Avian Biology 35 6 501 514 |
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English |
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We investigated the effects of increased egg production on body condition as well as on measures of reproductive performance in great skuas, Stercorarius skua , over two subsequent years. We experimentally increased egg production from the normal two to six eggs. Six eggs might also be produced under natural circumstances after repeated clutch loss. After the production of the last egg we measured: (i) body mass, (ii) pectoral muscle, and (iii) haematocrit, total red blood cell count and mean corpuscular volume, as indicators of body condition. We took the same measurements of control females who had produced the normal clutch of two eggs. The measurements were repeated one year after the manipulation, and survival, laying dates, clutch sizes and hatching success were recorded for up to three consecutive years. After producing six eggs, females were lighter, had smaller pectoral muscles and lower haematological values than control females. Hatching success of eggs was significantly reduced. Even one year after the experiment there were still differences in body condition. Annual survival was not affected by the manipulations, although there was an indication that survival costs depended on whether chicks were raised after the increased egg production. While pair bonds and egg sizes were not affected in the post‐experimental year, females started breeding significantly later than in the previous year. Two years after the experiment laying dates had advanced again and were not different from those of control females. This pattern of maintaining survival and egg sizes, but delaying breeding in the post‐experimental year was found for two independent groups of females which had both been subjected to increased egg production. These results present evidence that increased egg production can have long‐term effects on female body condition and aspects of reproduction. However, although present, the costs of extra eggs appear to have been relatively small in the great skua in comparison to the two other bird species for ... |
format |
Article in Journal/Newspaper |
author |
Kalmbach, Ellen Griffiths, Richard Crane, Jonathan E. Furness, Robert W. |
spellingShingle |
Kalmbach, Ellen Griffiths, Richard Crane, Jonathan E. Furness, Robert W. Effects of experimentally increased egg production on female body condition and laying dates in the great skua Stercorarius skua |
author_facet |
Kalmbach, Ellen Griffiths, Richard Crane, Jonathan E. Furness, Robert W. |
author_sort |
Kalmbach, Ellen |
title |
Effects of experimentally increased egg production on female body condition and laying dates in the great skua Stercorarius skua |
title_short |
Effects of experimentally increased egg production on female body condition and laying dates in the great skua Stercorarius skua |
title_full |
Effects of experimentally increased egg production on female body condition and laying dates in the great skua Stercorarius skua |
title_fullStr |
Effects of experimentally increased egg production on female body condition and laying dates in the great skua Stercorarius skua |
title_full_unstemmed |
Effects of experimentally increased egg production on female body condition and laying dates in the great skua Stercorarius skua |
title_sort |
effects of experimentally increased egg production on female body condition and laying dates in the great skua stercorarius skua |
publisher |
Wiley |
publishDate |
2004 |
url |
http://dx.doi.org/10.1111/j.0908-8857.2004.03271.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.0908-8857.2004.03271.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.0908-8857.2004.03271.x |
genre |
Great skua Stercorarius skua |
genre_facet |
Great skua Stercorarius skua |
op_source |
Journal of Avian Biology volume 35, issue 6, page 501-514 ISSN 0908-8857 1600-048X |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.0908-8857.2004.03271.x |
container_title |
Journal of Avian Biology |
container_volume |
35 |
container_issue |
6 |
container_start_page |
501 |
op_container_end_page |
514 |
_version_ |
1802644596916748288 |