There are some bridges around here where barn swallows take up residence during nesting season. It's spectacular to consider the ingenuity of their dirt-and-spit nests engineered in the most unlikley of places. For one thing, I should think it would be a particularly rough place for younguns to fledge. I saw these Saturday and they were busy about the work of getting their little condos cobbled onto the underside of this overpass.
Neat stuff!
