[CT Birds] Thrush Pics Bluff Point
David F Provencher
david.f.provencher at dom.com
Mon Oct 8 07:59:52 EDT 2012
I took a look at you pics. First I'll give you is my impression and then I'll explain why. The first four pics are of the same bird as you know, and that bird certainly looks good for Gray-cheeked. However I would identify it as Gray-cheeked/Bicknell's species. The fifth image is either another bird or the same as images 1 through 4. I suspect it to be a different bird however based on mandible pattern, but that can be deceptive based on angle. That bird I would also call Gray-cheeked/Bicknell's species. The last image has some important regions of the bird blocked buy foliage, but from what I can see it looks rather like a Swainson's actually.
Separating Gray-cheeked Thrush and Bicknell's Thrush off the breeding grounds by sight alone is very difficult and a significant number of identifications made that way are going to be wrong. While Bicknell's averages smaller and redder than Gray-cheeked, there is overlap with some Bicknell's being larger and duller and some Gray-cheeked being smaller and warmer brown. The bill pattern is often used as a tool as well but I think the pattern of yellow/pink versus black is somewhat variable and worrisome as a clinching clue. The birds you photographed were photographed in poor light, being in the canopy and under a cloudy sky. This is very much how these thrushes are often seen of course. My experience with many Bicknell's in the White Mountains is that they can look very different in terms of hue or tone of brown depending on the ambient lighting at the time of viewing. So I still feel the best way to identify these birds off the breeding ground is by voice. And even then the flight calls differ subtly. I heard 3 or 4 off these birds during the peak of morning flight and what I heard was too faint and muddled by background noise to be sure, though I felt what I was hearing in two instances most likely was Gray-cheeked. I know it is somewhat anticlimactic to see one of these sylvan songsters and come away with "I don't know," but as they say, sometimes you can't make a call.
The last image seems to show a distinctly warm buffiness to the breast combined with an eyering, though the loral area is obscured, and I would favor tha bird as a Swainson's. The bulk of Catharus thrushes at Bluff Yesterday morning were Swainson's, which is not surprising because there are always a lot of Swainson's Thrushes that go through Bluff's hot corner each fall.
Here's a link to Dave Sibley's post on this identification issue:
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