[EBB Sightings] Yellow House Finch in S.F.

Bob et al:

Google Bird Color and you will find some interesting web pages.  Real fast:
The color comes from pigment (like the color in paint) or structure (like
the colors of oil on water).  From pigment, the bird can make it or get it
from the diet (flamingo pink is from the brine shrimp color so zoo's often
add a dye to the food).  From structure you see iridescent colors
(hummingbirds gorget) or basic blue (all blue except a few old world
species).  Colors like green are a yellow pigment and blue refective
structure.  A green 'albino' bird would be blue because the yellow pigment
is missing and the blue is not from the missing pigment.  Back light a Jay's
blue feather and you will see a brown feather.

Good Birding,
Ralf Stinson

-----Original Message-----
From: sightings-bounces at diabloaudubon.com
[mailto:sightings-bounces at diabloaudubon.com] On Behalf Of Bob Hislop
Sent: Wednesday, June 10, 2009 17:21
To: Arlene Gemmill; sightings at diabloaudubon.com
Subject: Re: [EBB Sightings] Yellow House Finch in S.F.

Thanks Arlene and everyone for all the great feedback regarding yellow House
Finches.  Quite interesting in the sense that diet seems to be determining
plumage color.

Bob Hislop