Male-Biased Sex-Ratio of Dunlins Calidris alpina in the Gulf Of Gdańsk (Southern Baltic) During Autumn Migration
This long-term study (10 years) aimed to check if the sex-ratio of dunlins Calidris alpina at a stopover site in the southern Baltic region was biased. Two age classes among non-juvenile dunlins were recognised: immatures (2nd calendar year) and adults (> 2nd calendar year). There was a significa...
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Spanish Society of Ornithology
2015
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ftbioone:10.13157/arla.62.2.2015.335 2024-06-02T08:04:45+00:00 Male-Biased Sex-Ratio of Dunlins Calidris alpina in the Gulf Of Gdańsk (Southern Baltic) During Autumn Migration Włodzimierz Meissner Włodzimierz Meissner world 2015-12-01 text/HTML https://doi.org/10.13157/arla.62.2.2015.335 en eng Spanish Society of Ornithology doi:10.13157/arla.62.2.2015.335 All rights reserved. https://doi.org/10.13157/arla.62.2.2015.335 Text 2015 ftbioone https://doi.org/10.13157/arla.62.2.2015.335 2024-05-07T01:03:34Z This long-term study (10 years) aimed to check if the sex-ratio of dunlins Calidris alpina at a stopover site in the southern Baltic region was biased. Two age classes among non-juvenile dunlins were recognised: immatures (2nd calendar year) and adults (> 2nd calendar year). There was a significant male bias in the sample of 4,406 non-juvenile dunlins captured during their southward migration. Overall, 60.3% of immatures and 59.4% of adults were males. Particularly among adults, the proportion of males increased significantly after the start of autumn migration. The annual sex-ratios were consistently male biased, but varied somewhat and fluctuated in parallel for adults and immatures. One plausible explanation for the male bias is that males and females differ in migration strategy. Females may make longer flights and avoid stopover sites with unpredictable feeding conditions, such as the southern Baltic coasts, which provide low quality habitat. Assuming a balanced non-juvenile population sex ratio, the ‘missing’ females could stopover elsewhere in the Baltic or fly directly to the tidal areas of the Wadden Sea. The sex ratio in the study area may depend on wind conditions during the early phase of autumn migration. In some years, adverse weather may force more females than usual to stopover in the study area. Text Calidris alpina BioOne Online Journals Ardeola 62 2 335 342 |
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Open Polar |
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BioOne Online Journals |
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ftbioone |
language |
English |
description |
This long-term study (10 years) aimed to check if the sex-ratio of dunlins Calidris alpina at a stopover site in the southern Baltic region was biased. Two age classes among non-juvenile dunlins were recognised: immatures (2nd calendar year) and adults (> 2nd calendar year). There was a significant male bias in the sample of 4,406 non-juvenile dunlins captured during their southward migration. Overall, 60.3% of immatures and 59.4% of adults were males. Particularly among adults, the proportion of males increased significantly after the start of autumn migration. The annual sex-ratios were consistently male biased, but varied somewhat and fluctuated in parallel for adults and immatures. One plausible explanation for the male bias is that males and females differ in migration strategy. Females may make longer flights and avoid stopover sites with unpredictable feeding conditions, such as the southern Baltic coasts, which provide low quality habitat. Assuming a balanced non-juvenile population sex ratio, the ‘missing’ females could stopover elsewhere in the Baltic or fly directly to the tidal areas of the Wadden Sea. The sex ratio in the study area may depend on wind conditions during the early phase of autumn migration. In some years, adverse weather may force more females than usual to stopover in the study area. |
author2 |
Włodzimierz Meissner |
format |
Text |
author |
Włodzimierz Meissner |
spellingShingle |
Włodzimierz Meissner Male-Biased Sex-Ratio of Dunlins Calidris alpina in the Gulf Of Gdańsk (Southern Baltic) During Autumn Migration |
author_facet |
Włodzimierz Meissner |
author_sort |
Włodzimierz Meissner |
title |
Male-Biased Sex-Ratio of Dunlins Calidris alpina in the Gulf Of Gdańsk (Southern Baltic) During Autumn Migration |
title_short |
Male-Biased Sex-Ratio of Dunlins Calidris alpina in the Gulf Of Gdańsk (Southern Baltic) During Autumn Migration |
title_full |
Male-Biased Sex-Ratio of Dunlins Calidris alpina in the Gulf Of Gdańsk (Southern Baltic) During Autumn Migration |
title_fullStr |
Male-Biased Sex-Ratio of Dunlins Calidris alpina in the Gulf Of Gdańsk (Southern Baltic) During Autumn Migration |
title_full_unstemmed |
Male-Biased Sex-Ratio of Dunlins Calidris alpina in the Gulf Of Gdańsk (Southern Baltic) During Autumn Migration |
title_sort |
male-biased sex-ratio of dunlins calidris alpina in the gulf of gdańsk (southern baltic) during autumn migration |
publisher |
Spanish Society of Ornithology |
publishDate |
2015 |
url |
https://doi.org/10.13157/arla.62.2.2015.335 |
op_coverage |
world |
genre |
Calidris alpina |
genre_facet |
Calidris alpina |
op_source |
https://doi.org/10.13157/arla.62.2.2015.335 |
op_relation |
doi:10.13157/arla.62.2.2015.335 |
op_rights |
All rights reserved. |
op_doi |
https://doi.org/10.13157/arla.62.2.2015.335 |
container_title |
Ardeola |
container_volume |
62 |
container_issue |
2 |
container_start_page |
335 |
op_container_end_page |
342 |
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1800749398799417344 |