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Sex Promotes Spatial and Dietary Segregation in a Migratory Shorebird during the Non-Breeding Season

Several expressions of sexual segregation have been described in animals, especially in those exhibiting conspicuous dimorphism. Outside the breeding season, segregation has been mostly attributed to size or age-mediated dominance or to trophic niche divergence. Regardless of the recognized implicat...

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Autores principales: Catry, Teresa, Alves, José A., Gill, Jennifer A., Gunnarsson, Tómas G., Granadeiro, José P.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3316497/
https://www.ncbi.nlm.nih.gov/pubmed/22479448
http://dx.doi.org/10.1371/journal.pone.0033811
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author Catry, Teresa
Alves, José A.
Gill, Jennifer A.
Gunnarsson, Tómas G.
Granadeiro, José P.
author_facet Catry, Teresa
Alves, José A.
Gill, Jennifer A.
Gunnarsson, Tómas G.
Granadeiro, José P.
author_sort Catry, Teresa
collection PubMed
description Several expressions of sexual segregation have been described in animals, especially in those exhibiting conspicuous dimorphism. Outside the breeding season, segregation has been mostly attributed to size or age-mediated dominance or to trophic niche divergence. Regardless of the recognized implications for population dynamics, the ecological causes and consequences of sexual segregation are still poorly understood. We investigate the foraging habits of a shorebird showing reversed sexual dimorphism, the black-tailed godwit Limosa limosa, during the winter season, and found extensive segregation between sexes in spatial distribution, microhabitat use and dietary composition. Males and females exhibited high site-fidelity but differed in their distributions at estuary-scale. Male godwits (shorter-billed) foraged more frequently in exposed mudflats than in patches with higher water levels, and consumed more bivalves and gastropods and fewer polychaetes than females. Females tended to be more frequently involved and to win more aggressive interactions than males. However, the number of aggressions recorded was low, suggesting that sexual dominance plays a lesser role in segregation, although its importance cannot be ruled out. Dimorphism in the feeding apparatus has been used to explain sex differences in foraging ecology and behaviour of many avian species, but few studies confirmed that morphologic characteristics drive individual differences within each sex. We found a relationship between resource use and bill size when pooling data from males and females. However, this relationship did not hold for either sex separately, suggesting that differences in foraging habits of godwits are primarily a function of sex, rather than bill size. Hence, the exact mechanisms through which this segregation operates are still unknown. The recorded differences in spatial distribution and resource use might expose male and female to distinct threats, thus affecting population dynamics through differential mortality. Therefore, population models and effective conservation strategies should increasingly take sex-specific requirements into consideration.
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spelling pubmed-33164972012-04-04 Sex Promotes Spatial and Dietary Segregation in a Migratory Shorebird during the Non-Breeding Season Catry, Teresa Alves, José A. Gill, Jennifer A. Gunnarsson, Tómas G. Granadeiro, José P. PLoS One Research Article Several expressions of sexual segregation have been described in animals, especially in those exhibiting conspicuous dimorphism. Outside the breeding season, segregation has been mostly attributed to size or age-mediated dominance or to trophic niche divergence. Regardless of the recognized implications for population dynamics, the ecological causes and consequences of sexual segregation are still poorly understood. We investigate the foraging habits of a shorebird showing reversed sexual dimorphism, the black-tailed godwit Limosa limosa, during the winter season, and found extensive segregation between sexes in spatial distribution, microhabitat use and dietary composition. Males and females exhibited high site-fidelity but differed in their distributions at estuary-scale. Male godwits (shorter-billed) foraged more frequently in exposed mudflats than in patches with higher water levels, and consumed more bivalves and gastropods and fewer polychaetes than females. Females tended to be more frequently involved and to win more aggressive interactions than males. However, the number of aggressions recorded was low, suggesting that sexual dominance plays a lesser role in segregation, although its importance cannot be ruled out. Dimorphism in the feeding apparatus has been used to explain sex differences in foraging ecology and behaviour of many avian species, but few studies confirmed that morphologic characteristics drive individual differences within each sex. We found a relationship between resource use and bill size when pooling data from males and females. However, this relationship did not hold for either sex separately, suggesting that differences in foraging habits of godwits are primarily a function of sex, rather than bill size. Hence, the exact mechanisms through which this segregation operates are still unknown. The recorded differences in spatial distribution and resource use might expose male and female to distinct threats, thus affecting population dynamics through differential mortality. Therefore, population models and effective conservation strategies should increasingly take sex-specific requirements into consideration. Public Library of Science 2012-03-30 /pmc/articles/PMC3316497/ /pubmed/22479448 http://dx.doi.org/10.1371/journal.pone.0033811 Text en Catry et al. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Catry, Teresa
Alves, José A.
Gill, Jennifer A.
Gunnarsson, Tómas G.
Granadeiro, José P.
Sex Promotes Spatial and Dietary Segregation in a Migratory Shorebird during the Non-Breeding Season
title Sex Promotes Spatial and Dietary Segregation in a Migratory Shorebird during the Non-Breeding Season
title_full Sex Promotes Spatial and Dietary Segregation in a Migratory Shorebird during the Non-Breeding Season
title_fullStr Sex Promotes Spatial and Dietary Segregation in a Migratory Shorebird during the Non-Breeding Season
title_full_unstemmed Sex Promotes Spatial and Dietary Segregation in a Migratory Shorebird during the Non-Breeding Season
title_short Sex Promotes Spatial and Dietary Segregation in a Migratory Shorebird during the Non-Breeding Season
title_sort sex promotes spatial and dietary segregation in a migratory shorebird during the non-breeding season
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3316497/
https://www.ncbi.nlm.nih.gov/pubmed/22479448
http://dx.doi.org/10.1371/journal.pone.0033811
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