[EBB Sightings] Are Downy Woodpeckers Nest Predators?

It would not surprise me if Downy Woodpeckers were nest predators.  
During Contra Costa's breeding bird atlas work, I heard a ruckus at the 
Valle Vista trailhead south of Moraga.  It was a pair of Red-breasted 
Nuthatches diving at a Nuttall's Woodpecker which was poking its head in 
and out of a hole from the outside.  I saw the woodpecker remove and eat 
two eggs in spite of the nuthatches' best efforts.  A couple weeks later 
the woodpeckers were using the same hole as a nest.  It was confirmed 
breeding for both species as far as the atlas was concerned, but it was 
not a happy ending for the nuthatches.

- Joel Herr
Alamo

Hilary Powers wrote:
> This morning, I was treated to the sight of a male Downy Woodpecker 
> checking out a hole in a tree by Perkins, just up from Bellevue near 
> Lake Merritt. He looked around, looked in, picked out a splinter or 
> two, jumped in and out... all the typical "this is a nice apartment; 
> should I put down a deposit?" moves, and sweet as can be.
> Except.
> On March 25, the 4th-Wednesday GGAS walk watched in delight as a 
> Red-breasted Nuthatch dug that hole in that tree. The nuthatches 
> surely didn't bring off a family in the intervening week and a half, 
> but they  were not in sight this morning - just the woodpecker and the 
> hole.
> What happened?