Now What the Heck is THIS?

Found this industrious bit of work on my willows. What is the analysis? My first best guess is a very well-ordered woodpecker, followed by any insect possibilities.

Help!

 

Those are woodpecker holes. From what I can tell, it's from a Yellow-Bellied Sapsucker. Their holes are regularly spaced in rows.

 

Thanks napper - good job.

I was hoping that was the answer - I don't mind feeding birds, presuming they'll do less damage to the tree than if it were insects. Think I should fill the holes for the sake of the tree's health?

 

You can leave the hole as they will fill probably fill them with acorns.

http://www.beartrackersden.com/beartracker/images/acornwoodpeckergranary.jpg

 

The Acorn Woodpecker puts acorns in the holes of trees and they are on the Western part of the US and Mexico. I don't think other woodpeckers do that. Correct me if I'm wrong, though.

As for filling the holes, I don't think that you need to do that. If you feel you need to, you can put netting around the tree.

The Sapsucker is only here in the winter. Do you know if this was done last winter or just now, during the summer? If it was during the summer, then it is probably a Northern Flicker.

 

Napper, yes, you are correct. The acorn woodpecker is found only in the western region of the US. Bird migratory patterns are evolving so maybe one day we'll see them here!

 

I don't know if it was done recently or last winter. I just discovered it when I was trimming limbs, but the holes do not look fresh.