Hi All,
Not sure why, but these photos send out some real conflicting details which makes for a puzzling bird. Are there any additional photos that show the undertail pattern and the tertial pattern more clearly?
Problems with Great Crested - too pale ventrally, primary projection appears too short. [Edit: but I should add that the strong tertial contrast does suggest this species, as Andy mentioned. Also, the darkness of the face, olive-brown tones on the crown, and lack of much crest all suggest this species. Perhaps the lighting has blown out the coloration on the underparts in the photos (?). ]
Problems with Brown-crested - looks so grayish on the upperback, but fits for me structure-wise. Duller than most would be at this season. My guts leans this way based on the few images.
Problems with Ash-throated - looks too robust with thicker than typical bill. Tail pattern is like juvenile Ash-throated which should have been replaced by this date (thus not look like that of mystery bird). Rusty-edged secondaries are juvenile characteristic, should be mostly replaced by now.
Problems with La Sagra's - many: structure, coloration off.
Also, FWIW, the comparative shot of La Sagra's in Post #15 is a Loggerhead Kingbird.
Here are some La Sagra's examples:
http://www.flickr.com/photos/dave_irving/5254355629/
http://www.flickr.com/photos/richandrews/4153040521/
Chris