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Proceedings of the Royal Society B: Biological Sciences logoLink to Proceedings of the Royal Society B: Biological Sciences
. 1999 Apr 22;266(1421):771. doi: 10.1098/rspb.1999.0704

Condition-dependent variation in the blue-ultraviolet coloration of a structurally based plumage ornament

A J Keyser, G E Hill
PMCID: PMC1689904

Abstract

After years of investigation into the function of sexually dimorphic ornamental traits, researchers are beginning to understand how bright plumage colour in birds acts as an intraspecific signal. This work has focused primarily on pigment-based ornaments because they are highly variable in patch size, hue and brightness for some species. In contrast, structurally based ornaments have been little studied, in part because they do not appear to be as variable as pigment-based ornaments. We investigated a structurally based plumage ornament in a wild population of blue grosbeaks (Guiraca caerulea), a sexually dimorphic passerine. We report plumage variation that extends into the ultraviolet region of the spectrum. The pattern of covariation between four out of five elements of plumage variation suggests that structurally based ornamentation is pushed towards extreme expression of the trait as predicted by the sexual selection theory. The 'bluest' birds have the highest percentage of blue feathers on the body. These ornamental feathers reflect light maximally at the shortest wavelengths (ultraviolet), with the greatest intensity and the greatest contrast. Age may have some effect on expression of blueness. In addition, plumage variables are correlated with growth bars in tail feathers (a record of nutritional condition during moult in a non-ornamental trait). This suggests that the ornament is partially condition dependent. Thus, blue plumage in male grosbeaks may serve as an honest indicator of age and quality.

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Selected References

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  1. Bennett A. T., Cuthill I. C., Partridge J. C., Lunau K. Ultraviolet plumage colors predict mate preferences in starlings. Proc Natl Acad Sci U S A. 1997 Aug 5;94(16):8618–8621. doi: 10.1073/pnas.94.16.8618. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bowmaker J. K., Heath L. A., Wilkie S. E., Hunt D. M. Visual pigments and oil droplets from six classes of photoreceptor in the retinas of birds. Vision Res. 1997 Aug;37(16):2183–2194. doi: 10.1016/s0042-6989(97)00026-6. [DOI] [PubMed] [Google Scholar]
  3. Chen D. M., Collins J. S., Goldsmith T. H. The ultraviolet receptor of bird retinas. Science. 1984 Jul 20;225(4659):337–340. doi: 10.1126/science.6740315. [DOI] [PubMed] [Google Scholar]
  4. Chen D. M., Goldsmith T. H. Four spectral classes of cone in the retinas of birds. J Comp Physiol A. 1986 Oct;159(4):473–479. doi: 10.1007/BF00604167. [DOI] [PubMed] [Google Scholar]
  5. Dyck J. Structure and colour-production of the blue barbs of Agapornis roseicollis and Cotinga maynana. Z Zellforsch Mikrosk Anat. 1971;115(1):17–29. doi: 10.1007/BF00330211. [DOI] [PubMed] [Google Scholar]
  6. Finger E., Burkhardt D. Biological aspects of bird colouration and avian colour vision including ultraviolet range. Vision Res. 1994 Jun;34(11):1509–1514. doi: 10.1016/0042-6989(94)90152-x. [DOI] [PubMed] [Google Scholar]
  7. Hamilton W. D., Zuk M. Heritable true fitness and bright birds: a role for parasites? Science. 1982 Oct 22;218(4570):384–387. doi: 10.1126/science.7123238. [DOI] [PubMed] [Google Scholar]
  8. Hart N, Partridge J, Cuthill I., I Visual pigments, oil droplets and cone photoreceptor distribution in the european starling (Sturnus vulgaris) . J Exp Biol. 1998 May;201(Pt 9):1433–1446. doi: 10.1242/jeb.201.9.1433. [DOI] [PubMed] [Google Scholar]
  9. Johnsen A, Lifjeld JT, Rohde PA. Coloured leg bands affect male mate-guarding behaviour in the bluethroat. Anim Behav. 1997 Jul;54(1):121–130. doi: 10.1006/anbe.1996.0437. [DOI] [PubMed] [Google Scholar]
  10. Maier E. J. Ultraviolet vision in a passeriform bird: from receptor spectral sensitivity to overall spectral sensitivity in Leiothrix lutea. Vision Res. 1994 Jun;34(11):1415–1418. doi: 10.1016/0042-6989(94)90141-4. [DOI] [PubMed] [Google Scholar]
  11. Mateos C, Carranza J. The role of bright plumage in male-male interactions in the ring-necked pheasant. Anim Behav. 1997 Nov;54(5):1205–1214. doi: 10.1006/anbe.1997.0516. [DOI] [PubMed] [Google Scholar]
  12. doi: 10.1098/rspb.1997.0221. [DOI] [PMC free article] [Google Scholar]
  13. doi: 10.1098/rspb.1998.0316. [DOI] [PMC free article] [Google Scholar]
  14. doi: 10.1098/rspb.1998.0315. [DOI] [PMC free article] [Google Scholar]
  15. Tobias MC, Hill GE. A test of sensory bias for long tails in the house finch. Anim Behav. 1998 Jul;56(1):71–78. doi: 10.1006/anbe.1998.0740. [DOI] [PubMed] [Google Scholar]
  16. Zahavi A. Mate selection-a selection for a handicap. J Theor Biol. 1975 Sep;53(1):205–214. doi: 10.1016/0022-5193(75)90111-3. [DOI] [PubMed] [Google Scholar]

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