Each summer we host an extended family of barn swallows on our north porch. In general, they are nice, happy company, raising lots of noisy children and devouring lots of flying bugs. Of course, the swallows are a tad messy, not being what you'd call potty-trained. That's why we only allow them to build their nests on the north porch, not the more desirable, from a birdbrain point of view, real estate of the front porch or the back porch.
Perhaps the single most desirable building site is on and behind the brass American eagle that spreads its wings above our front door. Streaks of bird excrement down our full view storm door does not enhance the domestic tranquility in our household. Nor does the mess dropping from nests above our front porch swing or from nests surrounding the table on our back porch. That's why they get the only north porch for the summer. It's a compromise that's evolved over time.
I'd noticed the first pair of swallows a week ago. They'd arrived from their winter sojourn by riding in on a warm south wind. After resting a few days, they started a nest in a corner of the back porch. I'm always amazed at how fast the assemblage of mud and twigs comes together in the wrong place.
So I ruthlessly tore down the offending structure and the birds spent the rest of the day bitching about my offense. Now they are rebuilding. It's on the north porch. I'll leave that nest alone.