For a few weeks during the summer of 2006 I had the privilege to watch a pair of Yellow-bellied Sapsuckers successfully raise a nice brood...from nest building to the end (just missed the first flights). It was fun watching the pair dig up their new "digs", and especially to watch them defend it ferociously against some Great-Crested Flycatchers who were interested in the newly made real-estate. It was also very cool as the birds, one at a time, would enter the cavity to dig it deeper...although deep inside I could hear the work going on from where I was standing. They would come out with their bill full of wood chips and spit them out, as in this image I took here (this one the male)
Great action. Without the back story i could be hard to interupt. I agree with the head being slightly soft (possibly due to movement because the timber adajcent seems to be sharp)
I had a similar experience last year (my first year in photography too) I observed a pair of Greater spotted Woodpeckers build their nest hole etc, Sadly the nest was eventually dispossessed by a couple of Starlings so I never got to see what happened to the little ones!
But as mentioned above the flying splinters of wood make this image something special, I hope I will be as lucky this year :)