What is it?

Hmmmm. looks like an Ivory-billed Sapsucker!

You've discovered a new species.

Interesting bird, Charlie. I lean towards the northern race of the reb-breasted. Head has a lot of the characteristics mentioned in Kaufman's Advanced Birding. That being a black lore and a white malar stripe. The back and sides seem a bit disheveled and I don't know quite what to make of that. As to the bill, I think that is just an artifact of the light. The leg looks that color too. Any other photos? Not an expert on these guys so I definitely will pass the ID baton on to any of our very knowledgable specialists.It did give me a few minutes of fun trying to figure out what you had. A thank you for that.

I looked again at the RAW file and do believe the beak is actually darker than my processed .jpg shows, though it appears lighter than illustrations of RBSS. I feel too that it is more closely related to RBSS, but the complete lack of the white wing side band and rather limited extent of the red color down into the back causes me to believe it a hybrid and like you I expect it is the northern variety rather than hybrid with red-naped sapsucker.

Interesting and I posted it to rec.birds and hope to get some thoughts from the knowledgeable birders there.

Looks like this should be a straight forward exposure looking at the tree bark, but the bird suggests rather bright light with glare off the beak and darks hiding some detail. Iso 100 should give a bit more dynamic range, maybe lift the blacks a little in PS and likewise decrease the highlights unless you have allready done so. Very interesting bird for sure, interested to see what the id experts have to say - I'm not one. I like the vertical format but personally might have positioned the bird a little higher in the frame. No one says you have to do it "my" way though.

For me this is a Red-breasted Sapsucker. There's enough variation within the species that I don't think it has to be a hybrid with a Red-naped Sapsucker, although that happens often enough for all of the Red-breasted birds seen in AZ to be examined closely and many of them to be called hybrids of some degree.

The bill color seen here is glare - the true color is hinted at along the bottom edge.

The white wing patch is partially obscured by the feathers of the flank covering it - I see this happen with many other birds at times.

I don't see enough of these to have ever seen the "flank" feathers cover the large white wing marking, but that crossed my mind as a possibility, Richard. I also feel this is likely a RBSS, northern variety.

Thanks all for comments and if I get some interesting responses on rec.birds I'll post them.