Abstract
AbstractRed, orange, and yellow carotenoid-colored plumages have been considered honest signals of condition. We comprehensively quantified carotenoid signals in the social, sexually-dimorphic tanager genus Ramphocelus using scanning electron microscopy (SEM), finite-difference time-domain (FDTD) optical modeling, liquid chromatography–mass spectrometry (LC-MS), and spectrophotometry. Despite males having significantly more saturated color patches, males and females within a species have equivalent amounts and types of carotenoids. Male, but not female, feathers have elaborate microstructures which amplify color appearance. Expanded barbs enhance color saturation (for the same amount of pigment) by increasing the transmission of optical power through the feather. Dihedral barbules (vertically-angled, strap-shaped barbules) reduce total reflectance to generate “super black” plumage, an optical illusion to enhance nearby color. Dihedral barbules paired with red carotenoid pigment produce “velvet red” plumage. Together, our results suggest that a widely cited index of honesty—carotenoid pigments—cannot fully explain male appearance. We propose that males are selected to evolve amplifiers of honest signals—in this case, microstructures that enhance appearance —that are not necessarily themselves linked to quality.
Publisher
Cold Spring Harbor Laboratory
Reference87 articles.
1. Brainard, D. H. , B. A. Wandell , and E.-J. Chichilnisky . 1993. Color constancy: from physics to appearance. Curr. Dir. Psychol. Sci. 165–170. JSTOR.
2. Male Topi Antelopes Alarm Snort Deceptively to Retain Females for Mating
3. Pigments in hybrid, variant and melanic tanagers (birds);Comp. Biochem. Physiol,1970
4. Acoustic signals, arms races and the costs of honest signalling;Florida Entomol,1988
5. Burns, K. J. , K. J. McGraw , A. J. Shultz , M. C. Stoddard , and D. B. Thomas . 2017. Advanced methods for studying pigments and coloration using avian specimens. P. in The Extended Specimen: Emerging Frontiers in Collections-Based Ornithological Research. CRC press.
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