QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online March 17, 2006
Journal of Experimental Biology 209, 1245-1250 (2006)
Published by The Company of Biologists 2006
doi: 10.1242/jeb.02115

This Article Summary Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Shawkey, M. D. Articles by Hill, G. E. Search for Related Content PubMed PubMed Citation Articles by Shawkey, M. D. Articles by Hill, G. E.

Significance of a basal melanin layer to production of non-iridescent structural plumage color: evidence from an amelanotic Steller's jay (Cyanocitta stelleri)

Matthew D. Shawkey^* and Geoffrey E. Hill

Department of Biological Sciences, 331 Funchess Hall, Auburn University, Auburn, AL 36849, USA

View larger version (102K): [in a new window]   Fig. 1. Photograph of the amelanotic Steller's jay in Boulder County, CO, USA from which the feathers in this study were taken. Photograph by Bill Schmoker.

View larger version (22K): [in a new window]   Fig. 2. Raw (A) and normalized (B) reflectance spectra of an amelanotic Steller's jay feather, a normal blue Steller's jay feather (solid line) and a white chicken feather. Reflectance values in B were all divided by the peak reflectance value of each curve to obtain a maximum reflectance of 1. The spectra are presented both ways to facilitate comparison of both overall reflectance (A) and the shapes of the curves for the different feathers (B).

View larger version (94K): [in a new window]   Fig. 3. Feather microstructure, Fourier power spectra and predicted reflectance spectra of a blue Steller's Jay feather (A,D,G), an amelanotic Steller's jay feather (B,E,H) and a white chicken feather (C,F,I). (A–C) TEM micrographs of barbs (scale bars, 1 µm) with insets in A and b showing close-ups of spongy layer (scale bars, 500 nm). (D–F) Two-dimensional Fourier power spectrum of TEM of colour-producing structures in these feathers. The length and direction, respectively, of a vector from the origin to each value in the power spectrum indicates its spatial frequency and direction. The colour indicates the magnitude of each value in the power spectrum (scale on right). (G–I) Predicted reflectance spectra based on these Fourier analyses and the known refractive indices of keratin (1.54) and air (1.0) (for details, see Prum and Torres, 2003). c, cortex; sl, spongy layer; m, melanin granules; v, vacuoles.