Michael Hobbs wrote:

>In the National Geographic guide, there's a picture of a "tan-stripe
>phase" of the White-throated Sparrow that could be what you described.
>It looks in the book like a cross between a GCSP and a WTSP.
>

and Louise Martell wrote:

Your bird sounds like a white-throated sparrow. They are much more
>common in the Midwest than here in the Northwest.

I often get to vote on sightings as a member of various committees and I
have been quite dubious about some reports and certain identifications
others have made. However, I have become almost accustomed to making an
identification and having the local folks believe me without much
difficulty, so it is very healthy to receive two back to back messages
questioning what I saw. The bird did come back and allowed me to ask two
question:

why isn't it a White-throated Sparrow and
why isn't it a Golden-crowned Sparrow.

I think I can answer both of these questions.

First, it is not a White-throated Sparrow because:

- its too large
- while the throat is white, it does not contrast with the breast and neck
as much as it should, there is no dark outline to the white throat.
- the central crown stripe is yellow at its extreme anterior point (at the
start of the culmen)
- the dark eye line is a bold and thick at its rear end, but it dissapears
just before it reaches the eye.
-the head is slightly peaked, unlike the rounded head of a White-throat.
- the back is not as rusty as on a typical White-throated Sparrow.


Second, its not a Golden-crown because:

- the yellow at the front of the supercillium is too bright and extensive.
- the yellow on the central crown stripe is not extensive enough.
- it has a dark eye-line.
- the supercilium is broader than on nearby Golden-crowns.
- the lateral crown stripes are placed higher up on the head than on a
Golden-crown, therefore restricting the central crown stripe to a thin, not
wide band.
- the white throat is more obvious than on other Golden-crowns, its pure white.
- the breast is too grey for a Golden-crown, lacking a brown wash.
- the wings appear too short (primary extension) for a Golden-crown.
- the posterior end of the central crown stripe is unstreaked,
Golden-crowns have streaked central crown stripes as they approach the nape
(at least the dull Golden-crowns).
- The bill looks a litte small for a Golden-crown.

In most features this bird looks smack dab in the middle, between a
Golden-crown and a White-throated Sparrow. I have been able to get a couple
of more photos, hopefully they will turn out.

Michael and Louise, thanks for focusing my attention by making your suggestions.

Good birding,

Alvaro Jaramillo "You are better off not knowing
Half Moon Bay, CA how sausages and laws are made"
alvaro at quake.net Otto von Bismarck,
but I saw it in a fortune cookie!

http://www.quake.net/~alvaro/index.html