Female ornamentation parental quality and compet

Authors: Matteo Griggio Valeria Zanollo Herbert Hoi

Publish Date: 2010/02/06

Volume: 28, Issue: 3, Pages: 455-462

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Abstract

The evolution of female ornaments is poorly understood Recent evidence suggests not only that female ornaments may be genetic correlates of selection on males but may also have evolved through male mate choice and/or through female–female aggressive interactions In the rock sparrow Petronia petronia both sexes have a carotenoidbased yellow patch that is sexually selected by both sexes The benefits that male may gain from choosing an attractive female remain unidentified Both parents participate in caring for the young so there should be mutual mate choice because males and females should both benefit from choosing a good parent good parent hypothesis GPH Moreover it has already been demonstrated that the yellow patch in males is also a badge of status armament Therefore the yellow patch could also serve as both ornament and armament in females dual utility hypothesis DUH We investigated the hypothesis that male and female yellow patch size signals parental quality in the field We tested by an experiment in captivity the signal function of the yellow patch in female–female aggressive interactions for access to food Yellow patch size correlated with paternal but not maternal feeding rates Thus this study supports the hypothesis that yellow patch dimension signals male parental quality but there is no evidence for the GPH to explain female ornamentation In the experiment females with relatively large yellow patches had earlier access to food than those with small patches These results seem to suggest that a sexually selected carotenoidfeather signal may be used in female–female competition in agreement with the DUH Males may benefit from choosing well ornamented females because these may be superior competitorsWe thank the many assistants who helped with the fieldwork and the KLIVV staff in particular Christa Grabmayer for assistance during the experiment We are very grateful to Toni Mingozzi for practical help and to Claudio Carere Andrea Pilastro Marco Girardello and two anonymous reviewers for their constructive comments that improved an earlier version of the manuscript All of the manipulations of birds performed during this study comply with the current laws of the country in which they were performed

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