Scientific Correspondence

Nature 396, 28-29 (5 November 1998) | doi:10.1038/23838

Coherent light scattering by blue feather barbs

Richard O. Prum1,2, Rodolfo H. Torres3, Scott Williamson2 & Jan Dyck4

The structural colours of avian feather barbs are created by the scattering of light from the spongy matrix of keratin and air in the medullary layer of the barbs1,5. However, the precise physical mechanism for the production of these colours is still controversial1,3,4,6. Here we use a two-dimensional (2D) Fourier analysis of the spatial variation in refractive index of the blue feather barbs of the plum-throated cotinga (Cotinga maynana, Cotingidae) to show that the colour is produced by constructive interference between light waves scattered coherently by the nanostructured keratin-air matrix of the barbs.

  1. Natural History Museum, and Departments of Lawrence, Kansas 66045, USA
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  2. Ecology and Evolutionary Biology, and, Lawrence, Kansas 66045, USA
  3. Mathematics, University of Kansas, Lawrence, Kansas 66045, USA
  4. Institute of Population Biology, Universitetsparken 15, DK-2100 Copenhagen, Denmark