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

	<444F253F9EA24D3F847836728D280835 at RHSLaptop>

Hi all,

I grew up in Hawai'i, so to me, House Finches were normally orange.  It
was exciting to see my first red one.

When I moved to California, we had a lot of orange House Finches at the
feeders, probably 50/50 vs the reds.  Now it is exclusively red.  Could it
be because of my supplemental feeding? "Eat your sunflower seeds and
you'll grow up bright and red like your (putative) father!"

Strictly speaking, Geoff Hill's work showed that in the lab, given a diet
with large amounts of added carotenoids, he could effect the color of
feathers in the next molt.  To my knowledge, no one has demonstrated this
effect in the wild. That could make a good thesis project to demonstrate
how wild birds feeding on real foods are affected by diet.

One claim by Hill was that yellow HoFi are all pale - bright birds are
either red or orange. Yet I did have a bright yellow HoFi here about 15
years ago.

Jaan Lepson
Livermore, ALA




On Thu, June 11, 2009 12:37 pm, Ralf Stinson wrote:
> 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
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-- 
Jaan Lepson

University of California
Space Sciences Laboratory
7 Gauss Way
Berkeley, CA 94720-7451