Data from: Increased male bias in eider ducks can be explained by sex-specific survival of prime-age breeders
In contrast to theoretical predictions of even adult sex ratios, males are dominating in many bird populations. Such bias among adults may be critical to population growth and viability. Nevertheless, demographic mechanisms for biased adult sex ratios are still poorly understood. Here, we examined p...
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ftdryad:oai:v1.datadryad.org:10255/dryad.175553 2023-05-15T18:20:27+02:00 Data from: Increased male bias in eider ducks can be explained by sex-specific survival of prime-age breeders Ramula, Satu Öst, Markus Lindén, Andreas Karell, Patrik Kilpi, Mikael Finland 1986-2013 2018-04-11T18:26:30Z http://hdl.handle.net/10255/dryad.175553 https://doi.org/10.5061/dryad.g1hf29c unknown doi:10.5061/dryad.g1hf29c/1 doi:10.1371/journal.pone.0195415 doi:10.5061/dryad.g1hf29c Ramula S, Öst M, Lindén A, Karell P, Kilpi M (2018) Increased male bias in eider ducks can be explained by sex-specific survival of prime-age breeders. PLOS ONE 13(4): e0195415. http://hdl.handle.net/10255/dryad.175553 eider demography matrix population model sex ratio two-sex model Article 2018 ftdryad https://doi.org/10.5061/dryad.g1hf29c https://doi.org/10.5061/dryad.g1hf29c/1 https://doi.org/10.1371/journal.pone.0195415 2020-01-01T16:06:54Z In contrast to theoretical predictions of even adult sex ratios, males are dominating in many bird populations. Such bias among adults may be critical to population growth and viability. Nevertheless, demographic mechanisms for biased adult sex ratios are still poorly understood. Here, we examined potential demographic mechanisms for the recent dramatic shift from a slight female bias among adult eider ducks (Somateria mollissima) to a male bias (about 65% males) in the Baltic Sea, where the species is currently declining. We analysed a nine-year dataset on offspring sex ratio at hatching based on molecularly sexed ducklings of individually known mothers. Moreover, using demographic data from long-term individual-based capture-recapture records, we investigated how sex-specific survival at different ages after fledgling can modify the adult sex ratio. More specifically, we constructed a stochastic two-sex matrix population model and simulated scenarios of different survival probabilities for males and females. We found that sex ratio at hatching was slightly female-biased (52.8%) and therefore unlikely to explain the observed male bias among adult birds. Our stochastic simulations with higher survival for males than for females revealed that despite a slight female bias at hatching, study populations shifted to a male-biased adult sex ratio (> 60% males) in a few decades. This shift that was driven by prime reproductive-age individuals (≥5-year-old), with sex-specific survival of younger age classes playing a minor role. Hence, different age classes contributed disproportionally to population dynamics. We argue that an alternative explanation for the observed male dominance among adults - sex-biased dispersal - can be considered redundant and is unlikely, given the ecology of the species. The present study highlights the importance of considering population structure and age-specific vital rates when assessing population dynamics and management targets. Article in Journal/Newspaper Somateria mollissima Dryad Digital Repository (Duke University) |
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Dryad Digital Repository (Duke University) |
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topic |
eider demography matrix population model sex ratio two-sex model |
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eider demography matrix population model sex ratio two-sex model Ramula, Satu Öst, Markus Lindén, Andreas Karell, Patrik Kilpi, Mikael Data from: Increased male bias in eider ducks can be explained by sex-specific survival of prime-age breeders |
topic_facet |
eider demography matrix population model sex ratio two-sex model |
description |
In contrast to theoretical predictions of even adult sex ratios, males are dominating in many bird populations. Such bias among adults may be critical to population growth and viability. Nevertheless, demographic mechanisms for biased adult sex ratios are still poorly understood. Here, we examined potential demographic mechanisms for the recent dramatic shift from a slight female bias among adult eider ducks (Somateria mollissima) to a male bias (about 65% males) in the Baltic Sea, where the species is currently declining. We analysed a nine-year dataset on offspring sex ratio at hatching based on molecularly sexed ducklings of individually known mothers. Moreover, using demographic data from long-term individual-based capture-recapture records, we investigated how sex-specific survival at different ages after fledgling can modify the adult sex ratio. More specifically, we constructed a stochastic two-sex matrix population model and simulated scenarios of different survival probabilities for males and females. We found that sex ratio at hatching was slightly female-biased (52.8%) and therefore unlikely to explain the observed male bias among adult birds. Our stochastic simulations with higher survival for males than for females revealed that despite a slight female bias at hatching, study populations shifted to a male-biased adult sex ratio (> 60% males) in a few decades. This shift that was driven by prime reproductive-age individuals (≥5-year-old), with sex-specific survival of younger age classes playing a minor role. Hence, different age classes contributed disproportionally to population dynamics. We argue that an alternative explanation for the observed male dominance among adults - sex-biased dispersal - can be considered redundant and is unlikely, given the ecology of the species. The present study highlights the importance of considering population structure and age-specific vital rates when assessing population dynamics and management targets. |
format |
Article in Journal/Newspaper |
author |
Ramula, Satu Öst, Markus Lindén, Andreas Karell, Patrik Kilpi, Mikael |
author_facet |
Ramula, Satu Öst, Markus Lindén, Andreas Karell, Patrik Kilpi, Mikael |
author_sort |
Ramula, Satu |
title |
Data from: Increased male bias in eider ducks can be explained by sex-specific survival of prime-age breeders |
title_short |
Data from: Increased male bias in eider ducks can be explained by sex-specific survival of prime-age breeders |
title_full |
Data from: Increased male bias in eider ducks can be explained by sex-specific survival of prime-age breeders |
title_fullStr |
Data from: Increased male bias in eider ducks can be explained by sex-specific survival of prime-age breeders |
title_full_unstemmed |
Data from: Increased male bias in eider ducks can be explained by sex-specific survival of prime-age breeders |
title_sort |
data from: increased male bias in eider ducks can be explained by sex-specific survival of prime-age breeders |
publishDate |
2018 |
url |
http://hdl.handle.net/10255/dryad.175553 https://doi.org/10.5061/dryad.g1hf29c |
op_coverage |
Finland 1986-2013 |
genre |
Somateria mollissima |
genre_facet |
Somateria mollissima |
op_relation |
doi:10.5061/dryad.g1hf29c/1 doi:10.1371/journal.pone.0195415 doi:10.5061/dryad.g1hf29c Ramula S, Öst M, Lindén A, Karell P, Kilpi M (2018) Increased male bias in eider ducks can be explained by sex-specific survival of prime-age breeders. PLOS ONE 13(4): e0195415. http://hdl.handle.net/10255/dryad.175553 |
op_doi |
https://doi.org/10.5061/dryad.g1hf29c https://doi.org/10.5061/dryad.g1hf29c/1 https://doi.org/10.1371/journal.pone.0195415 |
_version_ |
1766197980474376192 |