On Sat, 2 Sep 2000 wrote:
> I would think that the reported fairy-wrens are largely resident and very
> unlikely to be vagrants, and they are the reason why the 'Black-winged
> Fairy-wren' is not a full species but rather a sub species or colour morph
> of White-winged.
I'm curious about the different plumage colours. Blue plumage is not
produced by a pigment but by structural properties of the feathers.
These properties cause blue light to be scattered - the sky is blue for
a similar reason. Pigments may also be present and modify the colour.
I believe black plumage is usually (always?) produced by dark pigment.
Does anyone know if the black plumage of "black" White-winged Fairy-wrens
is produced by loss of these structural properties ?
Or is dark pigment present in such levels that the scattering is swamped?
Is black plumage instead of blue, a common variation in birds?
Andrew Taylor
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