Tail feather elongation in Great Skuas Stercorarius skua: a sexual ornament signalling individual quality?
Capsule – In breeding Great Skuas on Skúvoy, Faroe Islands, central tail feather elongation was longer in males than females and was related to head size, laying date, egg volume, diet composition, and only in males also the tendency to incubate the clutch. Aims – Sexual ornaments, such as elongated...
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2020
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Online Access: | https://pure.knaw.nl/portal/en/publications/2690f2d9-8c93-455b-bd01-607db283649b https://doi.org/10.1080/00063657.2021.1882936 https://hdl.handle.net/20.500.11755/2690f2d9-8c93-455b-bd01-607db283649b https://pure.knaw.nl/ws/files/1045931134/Schreven_Hammer_2020_AAM.docx |
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ftknawnlpublic:oai:pure.knaw.nl:publications/2690f2d9-8c93-455b-bd01-607db283649b 2024-09-15T18:05:39+00:00 Tail feather elongation in Great Skuas Stercorarius skua: a sexual ornament signalling individual quality? Schreven, K.H.T. Hammer, Sjúrður 2020 application/vnd.openxmlformats-officedocument.wordprocessingml.document https://pure.knaw.nl/portal/en/publications/2690f2d9-8c93-455b-bd01-607db283649b https://doi.org/10.1080/00063657.2021.1882936 https://hdl.handle.net/20.500.11755/2690f2d9-8c93-455b-bd01-607db283649b https://pure.knaw.nl/ws/files/1045931134/Schreven_Hammer_2020_AAM.docx eng eng https://pure.knaw.nl/portal/en/publications/2690f2d9-8c93-455b-bd01-607db283649b info:eu-repo/semantics/openAccess Schreven , K H T & Hammer , S 2020 , ' Tail feather elongation in Great Skuas Stercorarius skua: a sexual ornament signalling individual quality? ' , Bird Study , vol. 67 , no. 3 , pp. 360-370 . https://doi.org/10.1080/00063657.2021.1882936 Diet egg volume Incubation laying date parental care spatial distribution international Plan_S-Compliant_NO spatial article 2020 ftknawnlpublic https://doi.org/10.1080/00063657.2021.188293620.500.11755/2690f2d9-8c93-455b-bd01-607db283649b 2024-07-29T23:40:18Z Capsule – In breeding Great Skuas on Skúvoy, Faroe Islands, central tail feather elongation was longer in males than females and was related to head size, laying date, egg volume, diet composition, and only in males also the tendency to incubate the clutch. Aims – Sexual ornaments, such as elongated tail feathers, allow birds to attract conspecifics of the opposite sex. In skuas, the smaller species have clearly elongated central tail feathers, while in the larger species, the elongation is marginal. We evaluate here if the modest elongation of the central tail feathers in Great Skuas is associated with ecological factors and thus could still function as a social signal. Methods and results – We caught 47 breeding Great Skuas on their nests on Skúvoy, Faroe Islands in 2013 and found that the central tail feathers were more elongated in males (mean 15.2 mm, n=20) than females (11.3 mm, n=27). This sexual dimorphism persisted when corrected for body size, as males are smaller than females. In both sexes, longer tail feather elongation was associated with a shorter head, an earlier laying date, and a higher bird-based proportion in the pair’s diet, while no spatial patterns were found. Moreover, during our catching attempts, males with a longer tail feather elongation were quicker back at the nest to incubate the clutch. Egg volume, but not chick body condition, increased with parent tail feather elongation. In a model including laying date, head size, and diet, only laying date persisted as significant predictor of the tail feather elongation, as earlier laying birds had shorter heads and ate more birds. Conclusion – We argue that the modest tail feather elongation in Great Skuas may signal individual quality for both sexes, and in males specifically also the nest attentiveness, even though this trait may seem ecologically irrelevant at first glance. Article in Journal/Newspaper Faroe Islands Skúvoy Stercorarius skua Royal Netherlands Academy of Arts and Sciences Research Portal (KNAW) Bird Study 67 3 360 370 |
institution |
Open Polar |
collection |
Royal Netherlands Academy of Arts and Sciences Research Portal (KNAW) |
op_collection_id |
ftknawnlpublic |
language |
English |
topic |
Diet egg volume Incubation laying date parental care spatial distribution international Plan_S-Compliant_NO spatial |
spellingShingle |
Diet egg volume Incubation laying date parental care spatial distribution international Plan_S-Compliant_NO spatial Schreven, K.H.T. Hammer, Sjúrður Tail feather elongation in Great Skuas Stercorarius skua: a sexual ornament signalling individual quality? |
topic_facet |
Diet egg volume Incubation laying date parental care spatial distribution international Plan_S-Compliant_NO spatial |
description |
Capsule – In breeding Great Skuas on Skúvoy, Faroe Islands, central tail feather elongation was longer in males than females and was related to head size, laying date, egg volume, diet composition, and only in males also the tendency to incubate the clutch. Aims – Sexual ornaments, such as elongated tail feathers, allow birds to attract conspecifics of the opposite sex. In skuas, the smaller species have clearly elongated central tail feathers, while in the larger species, the elongation is marginal. We evaluate here if the modest elongation of the central tail feathers in Great Skuas is associated with ecological factors and thus could still function as a social signal. Methods and results – We caught 47 breeding Great Skuas on their nests on Skúvoy, Faroe Islands in 2013 and found that the central tail feathers were more elongated in males (mean 15.2 mm, n=20) than females (11.3 mm, n=27). This sexual dimorphism persisted when corrected for body size, as males are smaller than females. In both sexes, longer tail feather elongation was associated with a shorter head, an earlier laying date, and a higher bird-based proportion in the pair’s diet, while no spatial patterns were found. Moreover, during our catching attempts, males with a longer tail feather elongation were quicker back at the nest to incubate the clutch. Egg volume, but not chick body condition, increased with parent tail feather elongation. In a model including laying date, head size, and diet, only laying date persisted as significant predictor of the tail feather elongation, as earlier laying birds had shorter heads and ate more birds. Conclusion – We argue that the modest tail feather elongation in Great Skuas may signal individual quality for both sexes, and in males specifically also the nest attentiveness, even though this trait may seem ecologically irrelevant at first glance. |
format |
Article in Journal/Newspaper |
author |
Schreven, K.H.T. Hammer, Sjúrður |
author_facet |
Schreven, K.H.T. Hammer, Sjúrður |
author_sort |
Schreven, K.H.T. |
title |
Tail feather elongation in Great Skuas Stercorarius skua: a sexual ornament signalling individual quality? |
title_short |
Tail feather elongation in Great Skuas Stercorarius skua: a sexual ornament signalling individual quality? |
title_full |
Tail feather elongation in Great Skuas Stercorarius skua: a sexual ornament signalling individual quality? |
title_fullStr |
Tail feather elongation in Great Skuas Stercorarius skua: a sexual ornament signalling individual quality? |
title_full_unstemmed |
Tail feather elongation in Great Skuas Stercorarius skua: a sexual ornament signalling individual quality? |
title_sort |
tail feather elongation in great skuas stercorarius skua: a sexual ornament signalling individual quality? |
publishDate |
2020 |
url |
https://pure.knaw.nl/portal/en/publications/2690f2d9-8c93-455b-bd01-607db283649b https://doi.org/10.1080/00063657.2021.1882936 https://hdl.handle.net/20.500.11755/2690f2d9-8c93-455b-bd01-607db283649b https://pure.knaw.nl/ws/files/1045931134/Schreven_Hammer_2020_AAM.docx |
genre |
Faroe Islands Skúvoy Stercorarius skua |
genre_facet |
Faroe Islands Skúvoy Stercorarius skua |
op_source |
Schreven , K H T & Hammer , S 2020 , ' Tail feather elongation in Great Skuas Stercorarius skua: a sexual ornament signalling individual quality? ' , Bird Study , vol. 67 , no. 3 , pp. 360-370 . https://doi.org/10.1080/00063657.2021.1882936 |
op_relation |
https://pure.knaw.nl/portal/en/publications/2690f2d9-8c93-455b-bd01-607db283649b |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1080/00063657.2021.188293620.500.11755/2690f2d9-8c93-455b-bd01-607db283649b |
container_title |
Bird Study |
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67 |
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container_start_page |
360 |
op_container_end_page |
370 |
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1810443181714571264 |