|
| |
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
Journal of Experimental Biology, Vol 202, Issue 24 3507-3522, Copyright © 1999 by Company of Biologists
JOURNAL ARTICLES |
RO Prum, R Torres, C Kovach, S Williamson and SM Goodman
Department of Ecology and Evolutionary Biology, and Natural History Museum, Dyche Hall, University of Kansas, Lawrence, KS 66045-2454, USA, Department of Mathematics, University of Kansas, Lawrence, KS 66045-2142, USA and Field Museum of Natural Hi.
We investigated the anatomy, nanostructure and biophysics of the structurally coloured facial caruncles of three species in a clade of birds endemic to Madagascar (Philepittinae, Eurylaimidae: Aves). Caruncle tissues of all species had reflectance spectra with prominent, peak hues between 403 and 528 nm. Dark blue Neodrepanis tissues had substantial reflectance in the near ultraviolet (320-400 nm), which is visible to birds but not to humans, providing the first evidence of ultraviolet skin colours in birds and the first indications of the possible function of ultraviolet skin colours in avian communication. These structural colours are produced by coherent scattering from arrays of parallel collagen fibres in the dermis. Tissues of Philepitta castanea were organized into hexagonal, crystal-like arrays, whereas Neodrepanis tissues were quasiordered. Predictions of the peak hues of reflectance ( &lgr; (max)) using Bragg's law were relatively accurate, but Bragg's law requires physical assumptions that are obviously violated by these structures. A two-dimensional discrete Fourier analysis of the spatial variation in refractive index within the tissues documented that all the tissues are substantially nanostructured at the appropriate spatial scale to scatter visible light coherently. Predicted reflectance spectra based on the two-dimensional Fourier power spectra are relatively accurate at predicting the hue and shape of the reflectance spectra of the tissues. These results confirm that the nanostructure of the collagen arrays determines the colours that are coherently scattered by these tissues. The evolution of the anatomy and nanostructure of asity caruncles is discussed.
This article has been cited by other articles:
|
|
 |
|
  R. M. de Ayala, N. Saino, A. P. Moller, and C. Anselmi Mouth coloration of nestlings covaries with offspring quality and influences parental feeding behavior Behav. Ecol., May 1, 2007; 18(3): 526 - 534. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. O. Prum, T. Quinn, and R. H. Torres Anatomically diverse butterfly scales all produce structural colours by coherent scattering J. Exp. Biol., February 15, 2006; 209(4): 748 - 765. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. O. Prum, J. A. Cole, and R. H. Torres Blue integumentary structural colours in dragonflies (Odonata) are not produced by incoherent Tyndall scattering J. Exp. Biol., October 15, 2004; 207(22): 3999 - 4009. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Cranial histology of pachycephalosaurs (Ornithischia: Marginocephalia) reveals transitory structures inconsistent with head-butting behavior Paleobiology, June 1, 2004; 30(2): 253 - 267.
|
|
|
|
|
|
R. O. Prum and R. H. Torres Structural colouration of mammalian skin: convergent evolution of coherently scattering dermal collagen arrays J. Exp. Biol., May 15, 2004; 207(12): 2157 - 2172. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. O. Prum and R. H. Torres A Fourier Tool for the Analysis of Coherent Light Scattering by Bio-Optical Nanostructures Integr. Comp. Biol., August 1, 2003; 43(4): 591 - 602. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. O. Prum and R. Torres Structural colouration of avian skin: convergent evolution of coherently scattering dermal collagen arrays J. Exp. Biol., July 15, 2003; 206(14): 2409 - 2429. [Abstract] [Full Text] [PDF]
|
|
