The dark Northern Flicker has not been seen again. I have been getting great input from friends who are out in the field more than I am and the consensus is that this bird is Melanistic, or has more dark pigmentation in his plumage than the norm. This is the photo that made me wonder if it was an Intergrade between the Yellow-shafted and Red-shafted. See the tiny bit of reddish feathering under its right wing? Since I didn't get another photo to confirm and the marks are true to Yellow-shafted, we'll have to call this one Melanistic.