It's a juvenile nuthatch. From the head pattern I would go with White-breasted, but not living in North America, I've never seen any of the species as fledglings, so would happily accept that it might not be.
I should have been more accurate. The Tennessee is probably a first-winter bird, but adults and youngsters look very similar in autumn.
I've photographed a number of PV's on my travels, including the second bird shown here which died whilst we were watching it. Anyway, these are...