This presumed (western?) Willow Flycatcher was photographed at Sam Nail Ranch, BBNP, Brewster county, Texas on May 25, 2013:
The general feel of the bird in the field was that of a rather brown Willow Flycatcher, but is the primary projection too long? It was not seen to vocalize during its c. 2 minute appearance, but when it was out of view we did hear a repeated call that might have been this bird, since it had an general Empid feel but was rather odd and not classic for any of the typical calls that I am familiar with - but note that while I get to hear lots of Least, and a fair few Acadians and Yellow-bellieds, I don't hear many Willows, and even fewer Alders, in my neck of the woods, which is southern/south coastal Texas.
It has a warm tawny tone to the lower rump, and the uppertail coverts are sharply demarcated and a contrasting darker brown. There is a pale cinnamon wash to the ventral flanks and vent. There is a suggestion of a paler "collar" sweeping up around the auricular.
These are all supposed features of White-throated Flycatcher E. albogularis. Click here to see a photos of White-throated Flycatcher. Another illustrated page about White-throated Flycatcher is here. So, can some forms of Willow Flycatcher have this suite of White-throated Flycatcher-like features? - I can find no reference to such individuals in my collection of literature:
Perhaps the only clear identifcation feature is voice - click here to listen to the distinctive vocalizations of White-throated Flycatcher .
NOTE: I found a Fall bird quite similar to this individual at exactly the same location: click here to see it.