Almost all wintering Fox Sparrows are of the Coast Northwest
Sooty form (unalaschcensis group). Pyle recognizes seven
subspecies within this group all of which probably occur, at
least during the fall, throughout western Cascadia.

The Western Slate-colored form (schistacea group) which includes
P.i.olivacea. This is the breeding Fox Sparrow of the Cascades,
but it winters mostly in s. California and Arizona. I don't
know of any verified winter records for this type in Cascadia.

Winter reports of red-form Fox Sparrows. It is unclear whether
most of these are P.i.altivagans which some include in the
Slate-colored group or one of the other two red-form subspecies.

We have been actively trying to sort out wintering Fox Sparrows
on the north coast of Oregon for about 3 years now and have found
Fox Sparrows that span the continuum for the sooty-form group.

http://home.pacifier.com/~neawanna/observatory/sparrow/fosp.html

Linda Barnes/Ed Swan wrote:
>
> I was wondering which Fox Sparrow sub-specied migrate and winter through the
> Puget Sound area. Is the breeding olivacea of the Cascades also the principal
> wintering sub-species in the lowlands of Puget Sound and are these part of the
> slate-colored group? Or is it one or more of the darker sooty races?
>
> Ed Swan
> Vashon Island
> swanbarn at concentric.net
> (206) 463-7976

--
Mike Patterson
Astoria, OR
celata at pacifier.com

A child who becomes acquainted with the birds about him
hears every sound and puzzles out its meaning with a cleverness
that amazes those with ears who hear not.

-Neltje Blanchan

http://www.pacifier.com/~mpatters/bird/bird.html