I've followed the discussion on line of the hybrid Tufted Titmouse and Black capped Chickadee and people who know a whole lot more than I do have pointed out some details that appear to confirm this birds hybrid status.
The best visible clue is the sharp demarcation of white on the face with a darker cap above. Tufted Titmice would be expected to have the color all the way down across the cheek. There were some other comments on some more subtle markings but it looks like this is the real deal.
Here are some other comments:
Mark Stackhouse said:
"The dark area on the chin was one of the things that I was hoping to get some input from the observer - I'm having a hard time deciding if those are actually black feathers on the chin, or dark gray (something that may be within the normal variation). The definition and shape of the line between the cap and the cheek do suggest a chickadee."
Allen Chartier said:
"I too was wondering about the chin, but as a bander I see a lot of bird with white underparts that show dark bases to the feathers, and the absence of some throat feathers could create this effect. Or, staining from sap..."
Tony Leukering said:
"I didn't have any problem with Matt's ID on this bird, it seems an obvious hybrid to me, with only some of those reasons already pointed out in this venue. I'd add two more:
1) The placemenht of the eye relative to the dark of the crown is intermediate between the two species -- TUTI has the eye entirely surrounded by pale, while BCCH has more of the eye within the black of the crown;
2) The nasal tufts are brown, something that is variable in BCCH (brown or black) and, as far as I'm aware, invariant in TUTI (black)."
So with that pretty much put to bed the next post is going to be another hybrid puzzle. Stay tuned!