Hi --

We have seen on definite (it sang) and one-two highly probable Bicknell's at
Rock Creek over past decade -- many Gray-cheeks don't give us long enough
(or complete enough) looks to really ID. We had one bird in spring for
almost 15 minutes in good light and it showed very short primary extension,
warm tail and less warm but not the dead-earth-brown upperparts of "typical"
Gray-cheeked, a rather short bill with lower mandible mostly yellow -- I am
not sure this last is too useful, but it gets mentioned as an ID criterion.

I have seen Bicknell's in Maine (on territory at Katahdin) that were fairly
gray-brown and others were warmer so...who knows?

Gail Mackiernan
Colesville, MD


on 09/29/2009 3:10 PM, pobrien776 at  wrote:

> Jeff,
> 
> What you describe could be the minimus subspecies of Gray-cheeked Thrush.
>  They breed in Newfoundland and, perhaps, northeast Quebec and are smaller
> than typical Gray-cheeks.  Most importantly, they are uniformly warm brown
> above whereas a Bicknell's shows contrasting chestnut tail and flatter
> gray-brown back with chestnut edges to the folded primaries.  The primary
> extension can be helpful if you can compare it to the tertial extension.  In
> Gray-cheeked the primary/tertial ratio tends to be greater than one (they are
> longer-distance migrants, e.g. from Alaska) and in Bicknell's it tends to be
> less than one.  Nobody said it would be easy.
> 
> I've seen only one certain minimus in Upper Watts Branch Park, so they do come
> through, but in low numbers.
> 
> Paul O'Brien
> Rockville, Mont. Co., MD
> 
<snip>