The Barn Swallow is one bird that the whole world has in common. These graceful steely-blue-and-peach birds chase midges and flies over the fields and ponds of every continent save Antarctica. Some individuals span nearly an entire hemisphere each year, as with North American breeders that may fly the length of South America to reach their wintering sites.
Barn Swallows have forged such a close relationship with us that it has crept right into their name. As people and buildings proliferated in North America, Barn Swallow populations increased an estimated hundredfold or more. The birds now only rarely use the caves that used to be their natural nest sites.
Some other of our feathered associates, such as the European Starling and House Sparrow, are infamous for turfing out native species from scarce nest cavities. But the Barn Swallow builds artful mud nests under eaves and bridges. Both sexes help, carrying mud a mouthful at a time, mixing in grass stems for stiffness and lining the inside with feathers—sometimes from the chickens in the barnyard.
Perhaps it’s their appetite for flying insects, including the biting kind, that first endeared Barn Swallows to us. Or maybe it’s their mastery of flight. I once spent an afternoon watching swallows foraging in a stiff wind over a Montana river. The low sun lit up clouds of insects swirling over the water, and it was fascinating to watch a darting swallow zero in on its prey, gulp it down, and then turn in an unbroken curve toward its next quarry. It’s an aerial showcase that happens, in the right season, pretty much the world over.