Immature chipping sparrows and some wintering adults can have lighter
colored bills. Immature chippies can be especially challenging.
One of the many, many facts learned in my recent attendance to a
wintering sparrows workshop in SE Arizona. I also noticed that the 1983
edition of the Golden bird guide (keep in my UW office desk as a backup)
mentions the seasonal light bill, and maybe some of the other guides plus
Bent's Life Histories may also. Will check this out; I don't get
Birding, but a quiz slide of a young chippie stumped a lot of us at the
AZ workshop. Then again, it is also possible that the Birding quiz ID may
really be in error!!! I hope someone else will answer this.

Maureen E. Ellis, me2 at u.washington.edu
***********************************************************************
On Tue, 13 Feb 1996, MR HUGH A JENNINGS wrote:

> The Dec. issue of Birding, published by the ABA, included a photo of a
> sparrow. The Feb. issue provided the answers to the Dec. quiz. The answer
> includes a detailed study of all the bird's features and why each leads to
> the final answer. In the case of this sparrow, a very distinctive feature
> was a very light yellow bill. However, the study did not mention this
> feature. The answer was that it was a Chipping Sparrow.
>
(snip)
>
> Hugh Jennings
> Bellevue, WA
> gfjc96a at prodigy.com
>
>