Female plumage coloration is sensitive to the cost of reproduction. An experiment in blue tits

• Published in: The Journal of animal ecology Vol. 81; no. 1; pp. 87 - 96
• Main Authors: Doutrelant, Claire, Grégoire, Arnaud, Midamegbe, Afiwa, Lambrechts, Marcel, Perret, Philippe
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing 01.01.2012; Blackwell Publishing Ltd; Blackwell; Wiley
• Subjects: Adaptation, Physiological; Animal and plant ecology; Animal biology; Animal communication; Animal ecology; Animal populations; Animal reproduction; Animal, plant and microbial ecology; Animals; Aves; Biodiversity and Ecology; Biological and medical sciences; bird; Birds; Body Composition; carotenoid‐based colour; Clutch size; Coloration; Colors; condition dependence; cost of reproduction; Ecology; Eggs; Environmental Sciences; Feathers; Feathers - physiology; Female; Female animals; Females; Food; France; Fundamental and applied biological sciences. Psychology; General aspects; handicap principle; Life histories; Life Sciences; Male; Male animals; Mate selection; Mating behavior; Pigmentation; Pigments; Plumage; Reproduction; Reproductive effort; Seasons; Sex; Sexual reproduction; Sexual selection; Songbirds - physiology; structural coloration; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; Wings; France; Handicap; structural coloration; Costs; handicap principle; Color; Plumage; cost of reproduction; carotenoid-based colour; Vertebrata; Reproduction; bird; Parus caeruleus; Female; Aves; Carotenoid; condition dependence; Coloration
• ISSN: 0021-8790; 1365-2656
• DOI: 10.1111/j.1365-2656.2011.01889.x

1. A growing number of studies suggest that female ornaments are linked to maternal quality and influence male mate choice. These findings challenge the traditional male-biased view of sexual selection and the hypothesis that female ornaments are the outcome of a genetic correlation with male ornaments. To further test the hypothesis that female traits have a function, it is now essential to investigate their honesty and to determine how signalling and reproduction interact in females. If female traits are honest indicators of quality, then they are likely to have a specific signalling function. 2. We investigated whether carry-over effects of reproduction might ensure the honesty of plumage colour signalling of a bird species with conspicuous UV-blue and yellow coloration, the blue tit Cyanistes caeruleus. Reproductive effort was manipulated by removing clutches, thereby forcing both sexes to reproduce twice and to raise chicks later in the breeding season when food is less abundant. In the year following this manipulation, we investigated the change in plumage in experimental and control males and females. The change was measured in the two putative feather ornaments, the UV-blue cap and the yellow breast, and another feather trait probably less likely to be sexually selected: the wing length. We also tested whether higher-quality females had their coloration less affected by the experiment. 3. We found that control but not manipulated males and females increased their signal towards UV. In addition, in the manipulated group, females that were able to lay more eggs had their UV-blue coloration less affected by the treatment. For yellow coloration, we found that manipulated yearlings but not manipulated adults decreased their yellow chroma in comparison with control. Lastly, our results show that the condition of the manipulated females tended to be positively correlated with yellow chroma. 4. These results show that the trade-offs between reproduction and signalling can ensure the honesty of conspicuous plumage traits in female and male blue tits. In addition, they suggest that female traits have the potential to evolve under sexual selection in this and other bird species.