The small square-tailed swallows nesting under these highway bridges were, until recently, a rarity confined to a few limestone caves and sinkholes in the Texas Hill Country and Mexico. Beginning in the 1960s they discovered that culverts and bridge underpasses imitate a cave mouth well enough, and the population exploded across Texas and beyond — one of the clearest cases anywhere of a bird whose range was transformed by road construction. They build open cup nests of mud pellets, often within a few feet of traffic.
Getting there
30.1300, -97.4000
Locations are approximate and may be inaccurate, on private land, or otherwise inaccessible. Check before you travel.
Hear it from the road
Whistlestop tells you this story automatically when you drive past. No searching, no tapping, nothing to ask.
