This Catharus thrush was at Blucher Park, Corpus Christi, Nueces county, Texas on May 10, 2014. Also present at the park that morning were a few 'Olive" Swainson's Thrushes, a possible "Russet" Swainson's Thrush (not seen by me), and a couple of typical (paler, rusty-toned) Veeries.
The photos clearly show the weak but distinct emargination on P6 plus none on P5 - this rules out Swainson's Thrush (has no emargination on P6) and Hermit Thrush (strongly emarginated on P6 plus visible emargination on P5). This leaves Gray-cheeked (GCTH), Bicknell's (BITH), and Veery (VEER):
In the field it suggested the dullest extreme of dark "Western/Newfoundland" Veery C. f. salicicolus/fuliginosus/subpallidus, but I feel that it is rather too dull, the visible markings on the neck/throat/chest sides are perhaps too strong, and the flanks are not a pure enough gray; thus I feel VEER is ruled out.
To me it looks like a "brown" GCTH, but I am not able to find any reference for GCTHs with such an overall brown tone. The nominate race from Newfoundland is warmer than the typical birds from the rest of its range, but only by a slight amount and less-so than BITH. I feel that this individual is too brown even for BITH... CLICK HERE to see another "brown" GCTH.
The photos allow a partial study of the primary-tip morphology: it seems typical of GCTH (per Pyle's ID Guide) in that P8 is obviously > P7 and P9 seems likely to be > P6. Pyle's ID Guide shows BITH as having P8 = P7 and P9 = P6 (or > by a tiny amount) :
The above pics are with natural lighting; the one below is with flash:
The following two photos (natural lighting) were taken about 8 mintues later at the same spot; so while I feel it is the same individual, I cannot be certain of it:
The arrow below points to the emargination on P6:
