As you say, fall Spizellas are difficult and, given that Chipping
Sparrow is a resident and Clay-colored is vagrant, it is understandable
that one my to default to the more expected species, except that
Clay-colored Sparrow is actually less rare than Chipping along the
Pacific Coast this time of year...

In this case the buffy breast, the strong mustachial mark and
the well defined crown stripe and contrast between the very gray
nape and the generally buffy tones over say this is a slam dunk
Clay-colored Sparrow.


--
Mike Patterson
Astoria, OR
I don't know...
http://www.surfbirds.com/community-blogs/northcoastdiaries/?p=3924