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

On Sep 29, 2009, at 1:19:38 PM, "Jeff Shenot" <> wrote:

Regarding the GCTH at the ridge, I think there is a strong possibility they were Bicknell's but obviously cannot conclude it. There were two birds well seen by myself and two other birders; I tried to point out some of the field marks to look for. I did not even comment on wing primary projections, as I could not really see anyhting noteworthy about this (although it is mentioned as a potentil field mark). Despite being seen at close range (40-50 feet), all birders noted that the birds appeared to be very small for a thrush. We watched for several minutes as they foraged (together) in a vine tangle and the foliage of trees about 20-25 feet from the ground. Although these thrushes are noted for foraging near the ground, I have seen Catharus sp. of thrushes foraging in the foliage and canopy of trees during migration, often eating fruits (mulberries, cherries and grapes). Both were obviously of the gray-cheeked thrush group - with no distinct eye ring, gray cheeks, uniform gray-brown color tone on the back of head, back, secondaries and tail. One bird may have been a HY bird with a trace of a wing bar, and was less brown. The other one was a solid warm brown tone in the back and elsewhere, and was not red or rusty toned. They both seemed to be more brown on average than what I expect for GCTH, so I think they may have been Bicknell's - but won't call it so. Both were silent the whole time.

Cheers!
Jeff Shenot
Croom MD