Tree Swallows, Nesting Naturally

 Woodpeckers do a huge favor to a lot of other birds when they chisel out their cavities. Red-headed, downy, hairy and red-bellied woodpeckers are the engineers, architects and contractors for most of the house-building. Flickers also excavate, but their slightly decurved bills are not quite as well-adapted to the task, so they'll often enlarge an existing cavity or choose a punkier dead tree to make their own. The huge cavities of pileated woodpeckers are a boon to wood ducks and great crested flycatchers.

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.

 It was lovely to see these birds nesting where they would naturally nest, in this Brigadoon for hole-nesters, safe from predators. Tree swallows are relatively recent colonists of southern Ohio and West Virginia, having expanded their range south quite a bit over the 30 years I've been monitoring nest boxes.

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!