Do feather-degrading bacteria affect sexually selected plumage color?

@article{Shawkey2008DoFB,
  title={Do feather-degrading bacteria affect sexually selected plumage color?},
  author={Matthew D. Shawkey and S. R. Madhavan Pillai and Geoffrey E. Hill},
  journal={Naturwissenschaften},
  year={2008},
  volume={96},
  pages={123-128}
}
Models of parasite-mediated sexual selection propose that males with more elaborate sexual traits will have fewer parasites. These models have generally been tested using metazoan or protozoan parasites of the blood, gut, or integument. Fewer studies have examined sexual ornaments in relation to bacterial infections. While most surface bacteria are harmless or beneficial, feather-degrading bacteria may have detrimental effects. In this study, we examined the relationships between overall… 
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It is suggested that the uropygial gland plays a specific role in regulating the abundance of feather-degrading bacteria that furthermore depends on the social environment of the host.
Bacterial degradability of an intrafeather unmelanized ornament: a role for feather-degrading bacteria in sexual selection?
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This is the first study to show differences in bacterial degradability among markings on the same feather and among unmelanized feather patches between males and females as predicted by sexual selection theory.
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References

SHOWING 1-10 OF 54 REFERENCES
Bacteria as an Agent for Change in Structural Plumage Color: Correlational and Experimental Evidence
TLDR
It is found that keratinolytic bacteria increased the brightness and purity, decreased the ultraviolet chroma, and did not affect the hue of structural color, suggesting that bacteria can alter structural plumage color through degradation.
EFFECTS OF COCCIDIAL AND MYCOPLASMAL INFECTIONS ON CAROTENOID-BASED PLUMAGE PIGMENTATION IN MALE HOUSE FINCHES
TLDR
Observations found that captive male House Finches experimentally infected with Isospora spp.
FEATHER-DEGRADING BACTERIA DO NOT AFFECT FEATHERS ON CAPTIVE BIRDS
TLDR
A test on whether a feather-degrading bacterium can degrade feathers of live birds housed outdoors under seminatural conditions found no evidence that B. licheniformis degraded wing feathers of Northern Cardinals when applied twice during the winter, despite the fact that it degraded Northern Cardinal feathers when incubated in the authors' laboratory.
High Parasite Load in House Finches (Carpodacus mexicanus) is Correlated with Reduced Expression of a Sexually Selected Trait
TLDR
This is the first study to monitor (via mark-recapture) the long-term effects of parasites on color and growth of plumage in individual birds and demonstrates that both ectoparasitic feather mite infestations and endoparAsitic avian pox viral infections during molt are correlated with poor physiological condition and reduced development of bright male plumage during the same molt period, thus supporting good genes models.
Plumage color as a dynamic trait: carotenoid pigmentation of male house finches (Carpodacus mexicanus) fades during the breeding season
TLDR
It is found that the hue of feathers faded significantly over the season, and researchers should more carefully track plum - age color expression during the course of a year, as seasonal color shifts may have important consequences for late- season male-male competitive interactions and flexible female mating tactics.
The Evolution of bird plumage colouration: a role for feather-degradation bacteria?
TLDR
The renewed interest on the evolution of plumage colouration can be traced back to Hamilton & Zuk (1982), who hypothesised that, within bird species, those indiArdeola 51(2), 2004, 375-383.
Sex, size, and plumage redness predict house finch survival in an epidemic
TLDR
The outbreak of Mycoplasma gallisepticum affected finches of both sexes but disproportionately killed males, shifting the sex ratio from male–biased to female–biased, and supporting the idea that plumage brightness serves as an indicator of condition, as proposed by the honest advertisement model of sexual selection.
Occurrence of feather-degrading bacilli in the plumage of birds
TLDR
It is suggested that feather degradation may contribute to the deterioration of feathers and be a selective force in the evolution and timing of molt during the summer when the bird becomes wet, for example during thunderstorms.
Soil and preen waxes influence the expression of carotenoid-based plumage coloration
TLDR
This is the first experimental study conducted on wild birds demonstrating that, in addition to pigment concentration, the presence of preen waxes and soils on feathers may contribute to variation in coloration.
Chemical warfare? Effects of uropygial oil on feather‐degrading bacteria
TLDR
Results suggest that birds may defend themselves against some feather-degrading bacteria using uropygial oil, which appears to enhance the growth of one weakly feather- Degrading isolate.
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