Long-term decline in a red-winged blackbird population: ecological causes and sexual selection consequences
Habitat loss and large-scale climate phenomena are widely implicated as causing decline in animal populations. I examined how both factors contributed to a precipitous decline in an Ontario red-winged blackbird ( Agelaius phoeniceus ) population using 16 years of data collected between 1974 and 1995...
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crroyalsociety:10.1098/rspb.2005.3211 2024-06-02T08:11:26+00:00 Long-term decline in a red-winged blackbird population: ecological causes and sexual selection consequences Weatherhead, Patrick J 2005 http://dx.doi.org/10.1098/rspb.2005.3211 https://royalsocietypublishing.org/doi/pdf/10.1098/rspb.2005.3211 https://royalsocietypublishing.org/doi/full-xml/10.1098/rspb.2005.3211 en eng The Royal Society https://royalsociety.org/journals/ethics-policies/data-sharing-mining/ Proceedings of the Royal Society B: Biological Sciences volume 272, issue 1578, page 2313-2317 ISSN 0962-8452 1471-2954 journal-article 2005 crroyalsociety https://doi.org/10.1098/rspb.2005.3211 2024-05-07T14:16:43Z Habitat loss and large-scale climate phenomena are widely implicated as causing decline in animal populations. I examined how both factors contributed to a precipitous decline in an Ontario red-winged blackbird ( Agelaius phoeniceus ) population using 16 years of data collected between 1974 and 1995. The decline was manifested as an almost 50% reduction in mean harem size, which reduced the opportunity for sexual selection threefold. Regional hay production, which should affect recruitment into the study population, also declined substantially. Correlation between blackbirds and hay may be coincidental, however, because annual changes in harem size were not associated with annual changes in hay production. This study coincided with an unprecedented positive phase of the North Atlantic Oscillation (NAO). Changes in harem size were correlated with winter NAO index values, suggesting that winter mortality contributed to the population decline. Positive correlation between harem size change and male return rates also supported the winter mortality hypothesis. Continued declines will cause this blackbird population to change from socially polygynous to socially monogamous. Study of red-winged blackbird winter ecology is needed to identify the proximate causes of mortality, whereas breeding studies can explore the consequences of relaxed sexual selection. Article in Journal/Newspaper North Atlantic North Atlantic oscillation The Royal Society Proceedings of the Royal Society B: Biological Sciences 272 1578 2313 2317 |
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The Royal Society |
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crroyalsociety |
language |
English |
description |
Habitat loss and large-scale climate phenomena are widely implicated as causing decline in animal populations. I examined how both factors contributed to a precipitous decline in an Ontario red-winged blackbird ( Agelaius phoeniceus ) population using 16 years of data collected between 1974 and 1995. The decline was manifested as an almost 50% reduction in mean harem size, which reduced the opportunity for sexual selection threefold. Regional hay production, which should affect recruitment into the study population, also declined substantially. Correlation between blackbirds and hay may be coincidental, however, because annual changes in harem size were not associated with annual changes in hay production. This study coincided with an unprecedented positive phase of the North Atlantic Oscillation (NAO). Changes in harem size were correlated with winter NAO index values, suggesting that winter mortality contributed to the population decline. Positive correlation between harem size change and male return rates also supported the winter mortality hypothesis. Continued declines will cause this blackbird population to change from socially polygynous to socially monogamous. Study of red-winged blackbird winter ecology is needed to identify the proximate causes of mortality, whereas breeding studies can explore the consequences of relaxed sexual selection. |
format |
Article in Journal/Newspaper |
author |
Weatherhead, Patrick J |
spellingShingle |
Weatherhead, Patrick J Long-term decline in a red-winged blackbird population: ecological causes and sexual selection consequences |
author_facet |
Weatherhead, Patrick J |
author_sort |
Weatherhead, Patrick J |
title |
Long-term decline in a red-winged blackbird population: ecological causes and sexual selection consequences |
title_short |
Long-term decline in a red-winged blackbird population: ecological causes and sexual selection consequences |
title_full |
Long-term decline in a red-winged blackbird population: ecological causes and sexual selection consequences |
title_fullStr |
Long-term decline in a red-winged blackbird population: ecological causes and sexual selection consequences |
title_full_unstemmed |
Long-term decline in a red-winged blackbird population: ecological causes and sexual selection consequences |
title_sort |
long-term decline in a red-winged blackbird population: ecological causes and sexual selection consequences |
publisher |
The Royal Society |
publishDate |
2005 |
url |
http://dx.doi.org/10.1098/rspb.2005.3211 https://royalsocietypublishing.org/doi/pdf/10.1098/rspb.2005.3211 https://royalsocietypublishing.org/doi/full-xml/10.1098/rspb.2005.3211 |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_source |
Proceedings of the Royal Society B: Biological Sciences volume 272, issue 1578, page 2313-2317 ISSN 0962-8452 1471-2954 |
op_rights |
https://royalsociety.org/journals/ethics-policies/data-sharing-mining/ |
op_doi |
https://doi.org/10.1098/rspb.2005.3211 |
container_title |
Proceedings of the Royal Society B: Biological Sciences |
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272 |
container_issue |
1578 |
container_start_page |
2313 |
op_container_end_page |
2317 |
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1800757582582775808 |