THE STRUCTURES PRODUCING “NON-IRIDESCENT” BLUE COLOUR IN BIRD FEATHERS
Article first published online: 20 AUG 2009
1957 The Zoological Society of London
Proceedings of the Zoological Society of London
Volume 129, Issue 4, pages 455–486, December 1957
How to Cite
AUBER, L. (1957), THE STRUCTURES PRODUCING “NON-IRIDESCENT” BLUE COLOUR IN BIRD FEATHERS. Proceedings of the Zoological Society of London, 129: 455–486. doi: 10.1111/j.1096-3642.1957.tb00307.x
- Issue published online: 30 OCT 2009
- Article first published online: 20 AUG 2009
- Accepted 14th May 1957
- 1The paper deals with the morphology and evolution of feathers of structural colours based on Tyndall's principle (short wavelengths of light are scattered from a cloudy medium, underlaid by pigmentations that absorb long wavelengths).
- 2The texture of the cloudy medium, usually of medullary origin, represents a dimensional extreme of vacuolization in feathers without Tyndall colour.
- 3Concealed bases of Tyndall-coloured feathers show primitive conditions, as found in dull-coloured feathers. Transitions between bases and bright terminal regions are interpreted as evolutionary steps, ontogenetically repeated in retrogression.
- 4There are few alternative configurations in pigmentation (1) of medullary or cortical portions, each of them evolved convergently in heterogeneous families: convergence is evident from differences in baso-terminal transitions (3).
- 5Divergence of related species (or of plumage regions in the same species) in late evolutionary phases is suggested by agreement in transitional, but differences in terminal, configurations.
- 6Evolution of alternative configurations may be controlled by available quantities of cells: these are sometimes correlated with the body volume.
- 7The taxonomic significance of Tyndall configurations has been discussed.
- 8Convergent evolution (4) of configurations in Alcedinidae and Thraupidae has been studied in detail.
- 9Double medullae in Alcedinidae and Thraupidae may represent stabilization of fluctuant conditions in other families.