Determinants of within‐ and among‐clutch variation in levels of maternal hormones in Black‐Headed Gull eggs
Summary 1. Females of egg‐laying vertebrates may adjust the development of their offspring to prevailing environmental conditions by regulating the deposition of hormones into their eggs. Within‐ and amng‐clutch variation in levels of steroid hormones were studied in the egg yolks of the Black‐Heade...
Published in: | Functional Ecology |
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Online Access: | http://dx.doi.org/10.1046/j.1365-2435.2002.00623.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-2435.2002.00623.x https://besjournals.onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2435.2002.00623.x |
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crwiley:10.1046/j.1365-2435.2002.00623.x 2024-06-02T08:15:59+00:00 Determinants of within‐ and among‐clutch variation in levels of maternal hormones in Black‐Headed Gull eggs T. G., Groothuis H., Schwabl 2002 http://dx.doi.org/10.1046/j.1365-2435.2002.00623.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-2435.2002.00623.x https://besjournals.onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2435.2002.00623.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Functional Ecology volume 16, issue 3, page 281-289 ISSN 0269-8463 1365-2435 journal-article 2002 crwiley https://doi.org/10.1046/j.1365-2435.2002.00623.x 2024-05-03T12:07:10Z Summary 1. Females of egg‐laying vertebrates may adjust the development of their offspring to prevailing environmental conditions by regulating the deposition of hormones into their eggs. Within‐ and amng‐clutch variation in levels of steroid hormones were studied in the egg yolks of the Black‐Headed Gull ( Larus ridibundus , Linnaeus) in relation to environmental conditions at the nest site. This species breeds in colonies of different densities and in different habitats, and the chicks hatch asynchronously. 2. Egg yolks contained very high levels of androstenedione, substantial levels of testosterone and moderate levels of 5α‐dihydrotestosterone. Oestrogen (17β‐oestradiol) was not detected. 3. Androgen levels increased strongly with laying order, irrespective of egg or yolk mass. This may compensate for the disadvantages of the later hatching chicks. These results have implications for adaptive hypotheses that were proposed for asynchronous incubation. 4. Eggs of lighter clutches contained more androgens, perhaps to compensate for a lower nutritional quality of these eggs. 5. Birds breeding in the periphery of a colony, being relatively more aggressive and having relatively large territories, laid eggs that contained more androgens than those of birds breeding in the centre. These high yolk androgen levels may facilitate growth and motor development of the chicks, which may be especially important for chicks developing at the periphery of a colony. Reduced levels may be adaptive for birds breeding in the centre, where risk of infectious diseases is high, since steroids may be immunosuppressive. 6. Corrected for nest distance, clutches of birds in high vegetation, where predation risk is less severe and therefore competition for nest sites perhaps high, contained relatively high levels of androgens. It is suggested that the level of yolk androgens reflects the hormonal condition of the female, that in turn is influenced by her characteristics such as her age and aggressiveness, and the level of social ... Article in Journal/Newspaper Black-headed Gull Larus ridibundus Wiley Online Library Functional Ecology 16 3 281 289 |
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Wiley Online Library |
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crwiley |
language |
English |
description |
Summary 1. Females of egg‐laying vertebrates may adjust the development of their offspring to prevailing environmental conditions by regulating the deposition of hormones into their eggs. Within‐ and amng‐clutch variation in levels of steroid hormones were studied in the egg yolks of the Black‐Headed Gull ( Larus ridibundus , Linnaeus) in relation to environmental conditions at the nest site. This species breeds in colonies of different densities and in different habitats, and the chicks hatch asynchronously. 2. Egg yolks contained very high levels of androstenedione, substantial levels of testosterone and moderate levels of 5α‐dihydrotestosterone. Oestrogen (17β‐oestradiol) was not detected. 3. Androgen levels increased strongly with laying order, irrespective of egg or yolk mass. This may compensate for the disadvantages of the later hatching chicks. These results have implications for adaptive hypotheses that were proposed for asynchronous incubation. 4. Eggs of lighter clutches contained more androgens, perhaps to compensate for a lower nutritional quality of these eggs. 5. Birds breeding in the periphery of a colony, being relatively more aggressive and having relatively large territories, laid eggs that contained more androgens than those of birds breeding in the centre. These high yolk androgen levels may facilitate growth and motor development of the chicks, which may be especially important for chicks developing at the periphery of a colony. Reduced levels may be adaptive for birds breeding in the centre, where risk of infectious diseases is high, since steroids may be immunosuppressive. 6. Corrected for nest distance, clutches of birds in high vegetation, where predation risk is less severe and therefore competition for nest sites perhaps high, contained relatively high levels of androgens. It is suggested that the level of yolk androgens reflects the hormonal condition of the female, that in turn is influenced by her characteristics such as her age and aggressiveness, and the level of social ... |
format |
Article in Journal/Newspaper |
author |
T. G., Groothuis H., Schwabl |
spellingShingle |
T. G., Groothuis H., Schwabl Determinants of within‐ and among‐clutch variation in levels of maternal hormones in Black‐Headed Gull eggs |
author_facet |
T. G., Groothuis H., Schwabl |
author_sort |
T. G., Groothuis |
title |
Determinants of within‐ and among‐clutch variation in levels of maternal hormones in Black‐Headed Gull eggs |
title_short |
Determinants of within‐ and among‐clutch variation in levels of maternal hormones in Black‐Headed Gull eggs |
title_full |
Determinants of within‐ and among‐clutch variation in levels of maternal hormones in Black‐Headed Gull eggs |
title_fullStr |
Determinants of within‐ and among‐clutch variation in levels of maternal hormones in Black‐Headed Gull eggs |
title_full_unstemmed |
Determinants of within‐ and among‐clutch variation in levels of maternal hormones in Black‐Headed Gull eggs |
title_sort |
determinants of within‐ and among‐clutch variation in levels of maternal hormones in black‐headed gull eggs |
publisher |
Wiley |
publishDate |
2002 |
url |
http://dx.doi.org/10.1046/j.1365-2435.2002.00623.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-2435.2002.00623.x https://besjournals.onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2435.2002.00623.x |
genre |
Black-headed Gull Larus ridibundus |
genre_facet |
Black-headed Gull Larus ridibundus |
op_source |
Functional Ecology volume 16, issue 3, page 281-289 ISSN 0269-8463 1365-2435 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1046/j.1365-2435.2002.00623.x |
container_title |
Functional Ecology |
container_volume |
16 |
container_issue |
3 |
container_start_page |
281 |
op_container_end_page |
289 |
_version_ |
1800740309968093184 |