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Do feather-degrading bacteria affect sexually selected plumage color?
Matthew D Shawkey1, Shreekumar R Pillai, Geoffrey E Hill
1Department of Biological Sciences, Auburn University, Auburn, AL, 36849, USA. shawkey@uakron.edu
Die Naturwissenschaften
|October 15, 2008
Summary
Male house finches with brighter plumage had fewer feather-degrading bacteria. This suggests plumage color signals bacterial load, potentially influencing sexual selection in birds.
Area of Science:
- Ecology
- Evolutionary Biology
- Animal Behavior
Background:
- Sexual selection models often link elaborate male traits to reduced parasite loads.
- Research has primarily focused on metazoan/protozoan parasites, with less attention to bacterial infections.
- Feather-degrading bacteria may negatively impact avian health and appearance.
Purpose of the Study:
- To investigate the relationship between bacterial load and carotenoid-based plumage color in house finches.
- To determine if plumage color signals overall bacterial burden or specific feather-degrading bacteria.
- To explore the role of bacteria in the sexual selection of house finch coloration.
Main Methods:
- Quantified bacterial loads (overall and feather-degrading) in house finches.
- Measured carotenoid-based plumage color in male house finches.
- Correlated bacterial loads with plumage color metrics.
Main Results:
- Males with redder plumage had significantly lower loads of feather-degrading bacteria.
- Overall bacterial loads did not differ between males with varying plumage redness.
- Plumage color appears to signal the presence of feather-degrading bacteria.
Conclusions:
- Plumage redness in male house finches may serve as an honest signal of reduced feather-degrading bacterial infection.
- Feather-degrading bacteria could play a role in the sexual selection of plumage color.
- Further research is needed to elucidate the direct/indirect mechanisms linking bacteria and plumage coloration.
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