I've been watching a starling for a couple of days now trying to take over the nest of a woodpecker. It literally stocks the woodpecker, At one point it actually did get in the tree hole but flew immediately out.
Here is the tree holes/home
the woodpecker looking out
for bad Guy Starling
Stocking Starling
They have fought off and on that I have seen,, Seems the starling is determined to take over,, I hope not,, I enjoy having this woodpecker living in my back yard.