These woodpeckers are called primary cavity nesters, meaning that they make their own holes. Great crested flycatchers and tree swallows are among the secondary cavity nesters who move in when the woodpeckers move out.
There were lots of these little blue beauties swirling around North Bend State Park, choosing the lower holes nearer the water for their nests.
Definitely the most confiding of cavity-nesting birds, tree swallows wait until the very last moment to leave, and grudgingly at that. When I'm checking nests, I'm sometimes able to lift an incubating tree swallow with my finger and count her eggs, then close the box again. You have to love a bird who stares you down and lets you do that. When I find a female bird incubating in a box, I usually let them alone until the next count, but sometimes I need a base count before the eggs hatch and have no choice but to intrude.
When we first moved to southeast Ohio in 1992, there was one spot in the county where we could see nesting swallows--a flooded embayment of the Ohio River. Now, they're everywhere, making new cocoa-brown and white babies like this one. In my boxes--sometimes two broods a season! And here, in these dead snags. Lovely to see.
Long may they nest at North Bend!