Extra-pair paternity, testes size and testosterone level in relation to colour polymorphism in the barn owl Tyto alba
In many bird populations, individuals display one of several genetically inherited colour morphs. Colour polymorphism can be maintained by several mechanisms one of which being frequency-dependent selection with colour morphs signalling alternative mating strategies. One morph may be dominant and te...
Published in: | Journal of Avian Biology |
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Format: | Article in Journal/Newspaper |
Language: | English |
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2004
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Online Access: | https://hdl.handle.net/11370/71b6dd4c-5840-4f49-991a-3b4d9c0d8de1 https://research.rug.nl/en/publications/71b6dd4c-5840-4f49-991a-3b4d9c0d8de1 https://doi.org/10.1111/j.0908-8857.2004.03294.x https://pure.rug.nl/ws/files/6681850/2004JAvianBiolRoulin.pdf |
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ftunigroningenpu:oai:pure.rug.nl:publications/71b6dd4c-5840-4f49-991a-3b4d9c0d8de1 2024-06-02T08:13:12+00:00 Extra-pair paternity, testes size and testosterone level in relation to colour polymorphism in the barn owl Tyto alba Roulin, A. Mueller, Wendt Sasvari, L. Dijkstra, C. Ducrest, A.L. Riols, C. Wink, M. Lubjuhn, T. 2004-11 application/pdf https://hdl.handle.net/11370/71b6dd4c-5840-4f49-991a-3b4d9c0d8de1 https://research.rug.nl/en/publications/71b6dd4c-5840-4f49-991a-3b4d9c0d8de1 https://doi.org/10.1111/j.0908-8857.2004.03294.x https://pure.rug.nl/ws/files/6681850/2004JAvianBiolRoulin.pdf eng eng https://research.rug.nl/en/publications/71b6dd4c-5840-4f49-991a-3b4d9c0d8de1 info:eu-repo/semantics/openAccess Roulin , A , Mueller , W , Sasvari , L , Dijkstra , C , Ducrest , A L , Riols , C , Wink , M & Lubjuhn , T 2004 , ' Extra-pair paternity, testes size and testosterone level in relation to colour polymorphism in the barn owl Tyto alba ' , Journal of Avian Biology , vol. 35 , no. 6 , pp. 492-500 . https://doi.org/10.1111/j.0908-8857.2004.03294.x WHITE-THROATED SPARROW RUFF PHILOMACHUS-PUGNAX ZONOTRICHIA-ALBICOLLIS GMELIN COPULATORY-BEHAVIOR PLUMAGE COLORATION GENETIC-EVIDENCE DNA FEMALE FERTILIZATIONS HETEROZYGOSITY article 2004 ftunigroningenpu https://doi.org/10.1111/j.0908-8857.2004.03294.x 2024-05-07T18:22:03Z In many bird populations, individuals display one of several genetically inherited colour morphs. Colour polymorphism can be maintained by several mechanisms one of which being frequency-dependent selection with colour morphs signalling alternative mating strategies. One morph may be dominant and territorial, and another one adopt a sneaky behaviour to gain access to fertile females. We tested this hypothesis in the barn owl Tyto alba in which coloration varies from reddish-brown to white. This trait is heritable and neither sensitive to the environment in which individuals live nor to body condition. In Switzerland, reddish-brown males were observed to feed their brood at a higher rate and to produce more offspring than white males. This observation lead us to hypothesize that white males may equalise fitness by investing more effort in extra-pair copulations. This hypothesis predicts that lighter Coloured males produce more extra-pair young, have larger testes and higher levels of circulating testosterone. However, our results are not consistent with these three predictions. First, paternity analyses of 54 broods with a total of 211 offspring revealed that only one young was not sired by the male that was feeding it. Second, testes size was not correlated with male plumage coloration suggesting that white males are not sexually more active. Finally, in nestlings at the time of feather growth testosterone level was not related to plumage coloration suggesting that this androgen is not required for the expression of this plumage trait. Our study therefore indicates that in the barn owl colour polymorphism plays no role in the probability of producing extra-pair young. Article in Journal/Newspaper Philomachus pugnax Ruff University of Groningen research database Journal of Avian Biology 35 6 492 500 |
institution |
Open Polar |
collection |
University of Groningen research database |
op_collection_id |
ftunigroningenpu |
language |
English |
topic |
WHITE-THROATED SPARROW RUFF PHILOMACHUS-PUGNAX ZONOTRICHIA-ALBICOLLIS GMELIN COPULATORY-BEHAVIOR PLUMAGE COLORATION GENETIC-EVIDENCE DNA FEMALE FERTILIZATIONS HETEROZYGOSITY |
spellingShingle |
WHITE-THROATED SPARROW RUFF PHILOMACHUS-PUGNAX ZONOTRICHIA-ALBICOLLIS GMELIN COPULATORY-BEHAVIOR PLUMAGE COLORATION GENETIC-EVIDENCE DNA FEMALE FERTILIZATIONS HETEROZYGOSITY Roulin, A. Mueller, Wendt Sasvari, L. Dijkstra, C. Ducrest, A.L. Riols, C. Wink, M. Lubjuhn, T. Extra-pair paternity, testes size and testosterone level in relation to colour polymorphism in the barn owl Tyto alba |
topic_facet |
WHITE-THROATED SPARROW RUFF PHILOMACHUS-PUGNAX ZONOTRICHIA-ALBICOLLIS GMELIN COPULATORY-BEHAVIOR PLUMAGE COLORATION GENETIC-EVIDENCE DNA FEMALE FERTILIZATIONS HETEROZYGOSITY |
description |
In many bird populations, individuals display one of several genetically inherited colour morphs. Colour polymorphism can be maintained by several mechanisms one of which being frequency-dependent selection with colour morphs signalling alternative mating strategies. One morph may be dominant and territorial, and another one adopt a sneaky behaviour to gain access to fertile females. We tested this hypothesis in the barn owl Tyto alba in which coloration varies from reddish-brown to white. This trait is heritable and neither sensitive to the environment in which individuals live nor to body condition. In Switzerland, reddish-brown males were observed to feed their brood at a higher rate and to produce more offspring than white males. This observation lead us to hypothesize that white males may equalise fitness by investing more effort in extra-pair copulations. This hypothesis predicts that lighter Coloured males produce more extra-pair young, have larger testes and higher levels of circulating testosterone. However, our results are not consistent with these three predictions. First, paternity analyses of 54 broods with a total of 211 offspring revealed that only one young was not sired by the male that was feeding it. Second, testes size was not correlated with male plumage coloration suggesting that white males are not sexually more active. Finally, in nestlings at the time of feather growth testosterone level was not related to plumage coloration suggesting that this androgen is not required for the expression of this plumage trait. Our study therefore indicates that in the barn owl colour polymorphism plays no role in the probability of producing extra-pair young. |
format |
Article in Journal/Newspaper |
author |
Roulin, A. Mueller, Wendt Sasvari, L. Dijkstra, C. Ducrest, A.L. Riols, C. Wink, M. Lubjuhn, T. |
author_facet |
Roulin, A. Mueller, Wendt Sasvari, L. Dijkstra, C. Ducrest, A.L. Riols, C. Wink, M. Lubjuhn, T. |
author_sort |
Roulin, A. |
title |
Extra-pair paternity, testes size and testosterone level in relation to colour polymorphism in the barn owl Tyto alba |
title_short |
Extra-pair paternity, testes size and testosterone level in relation to colour polymorphism in the barn owl Tyto alba |
title_full |
Extra-pair paternity, testes size and testosterone level in relation to colour polymorphism in the barn owl Tyto alba |
title_fullStr |
Extra-pair paternity, testes size and testosterone level in relation to colour polymorphism in the barn owl Tyto alba |
title_full_unstemmed |
Extra-pair paternity, testes size and testosterone level in relation to colour polymorphism in the barn owl Tyto alba |
title_sort |
extra-pair paternity, testes size and testosterone level in relation to colour polymorphism in the barn owl tyto alba |
publishDate |
2004 |
url |
https://hdl.handle.net/11370/71b6dd4c-5840-4f49-991a-3b4d9c0d8de1 https://research.rug.nl/en/publications/71b6dd4c-5840-4f49-991a-3b4d9c0d8de1 https://doi.org/10.1111/j.0908-8857.2004.03294.x https://pure.rug.nl/ws/files/6681850/2004JAvianBiolRoulin.pdf |
genre |
Philomachus pugnax Ruff |
genre_facet |
Philomachus pugnax Ruff |
op_source |
Roulin , A , Mueller , W , Sasvari , L , Dijkstra , C , Ducrest , A L , Riols , C , Wink , M & Lubjuhn , T 2004 , ' Extra-pair paternity, testes size and testosterone level in relation to colour polymorphism in the barn owl Tyto alba ' , Journal of Avian Biology , vol. 35 , no. 6 , pp. 492-500 . https://doi.org/10.1111/j.0908-8857.2004.03294.x |
op_relation |
https://research.rug.nl/en/publications/71b6dd4c-5840-4f49-991a-3b4d9c0d8de1 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1111/j.0908-8857.2004.03294.x |
container_title |
Journal of Avian Biology |
container_volume |
35 |
container_issue |
6 |
container_start_page |
492 |
op_container_end_page |
500 |
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1800736613399003136 |