[EBB Sightings] Steller's Jay Oddity - color blue

That explanation makes perfect sense... but I think something more must 
be happening with brown-head Steller's Jays. I saw one once too, from 
the window of a stopped train, and the effect was really spectacular.

The head of a Steller's Jay is normally more black than blue, and at 
least on the bird I was looking at (through binocs and for several 
minutes) the body was the usual intense blue. Meanwhile, instead of 
being darker than the body, the head and shoulders were about the same 
color value, or perhaps a bit lighter - a bright clear brown, almost 
fawn. I find it hard to imagine a lighting effect that would do that....

Ralf Stinson wrote:
> With the exception of a few birds in the old world, no birds have blue
> pigmentation in their feathers.  A pigment is a chemical that absorbs light
> of colors that it is not (red pigment absorbs green & blue light, so it
> looks red).  If you put clear oil on water, you see all the colors of the
> rainbow being reflected.  So the colors you see are not from any pigment,
> but from light interference pattern on the thin oil film.  There are
> microscopic structures in the feather that produce the blue reflected light.
> So for the blue head of the Jay, the microscopic structures were missing, or
> the angle of the light was such that you did not see the blue.  The dark
> blue color comes from brown pigment and the blue refecting microscopic
> structures.  I have seen bluebirds appear brown because of the lighting.
> After it moved into sunlight, it appeared blue.
> 
> Ralf Stinson
> 
> -----Original Message-----
> From: sightings-bounces at diabloaudubon.com
> [mailto:sightings-bounces at diabloaudubon.com] On Behalf Of Donald Lewis
> Sent: Sunday, July 05, 2009 22:40
> To: MDAS Sightings
> Subject: [EBB Sightings] Steller's Jay Oddity
> 
> Sunday morning,  a Steller's Jay with a totally brown head was feeding a
> fledgling on our deck. I've never seen a Jay like that. I guess a form of
> less-than-normal pigmentation but I'm curious if others have seen a similar
> bird.
> 
> Don Lewis
> Lafayette, CA
> donlewis at comcast.net


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