Mystery Bird: Yellow-bellied Flycatcher, Empidonax flaviventris

Let's see ... the flat bill and upright posture say flycatcher. The overall shape and color pattern rule out Kingbirds, Myiarchus, or any of the southwestern specialties. The strong white wing bars rule out any Phoebe. (A note -- young eastern phoebes can have strong buff wing bars -- very few guides get this right, not even Pyle.) The eye-ring rules out either Pewee, or any of the other Contopus. That leaves us with ....

Empidonax sp.

That's going to take a lot more work.

Empidonax flaviventris...I'm going to have to go with yellow-bellied flycatcher. However, the color saturation in the photo could be misleading.

NOOOO It's an Empidonax sp. without a sound track.
btw, is there a decent guide book to this family as we've struggled to id them in the US and Mexico on previous trips.
Comparing the size to the leaf I'll stick my neck out and say Least Flycatcher (E. minimus)--final answer.

Whew!... my first thoughts are that it isn't a Yellow-bellied (Empidonax flaviventris) because it appears more "streamlined" and that there is that dark/black along the nasal tuft/lores and supercillium, but is that light or wind ruffle?... I like Adrian's E. minimus because of the largish head for it's size, eye-ring (but is it complete?), and short tail but then again I could almost see an E. difficilis in there somewhere with it's orangish lower mandible but perhaps overall it's a little too olive instead of gray (or again, is that the dappled light?)... which takes me closer to a Dusky E. oberholseri but this is East Texas but then again how much of the greenish tinge on the photo's breast is reflected off the leaves below?... one of these days I'll get it right with a spurious "escaped from captivity" (and therefore totally non-North-American) or interspecific cross that can only be identified via DNA...

E. oberholseri would be problematic -- there is no dusky color on the underside of the bill. Same for Hammonds or Gray. Either of the "Western" flycatchers 'should' show a more pronounced eye-ring with a definite tear-drop shape at the rear of the eye. Willow and Alder should have a longer primary extension, I think, and less of an eye-ring. The bill would also be longer, although that could simply be a foreshortening effect. Acadian would have the same issues as Willow, with the exception of the eye-ring.

That leaves us with Least or Yellow-bellied (or something that didn't read the book). The larger version didn't seem to be as yellow on the throat (the belly is yellow in at least some plumages of most empies), but it's not clear enough to say. The head does seem large, without the crested effect we tend to see in YB, but the primary extension seems a bit long for Least.

I think I'm stuck there.