Barn Swallows come back every April

Of the six species of swallows that breed in the eastern United States, the Barn Swallow is the only one with the characteristic swallow tail. Its long forked tail gives it excellent maneuverability in flight and gives us a handy field mark for identification. Like other natural things, the Barn Swallow has sometimes been hurt by human activity; but by nesting in buildings and other manmade structures it has also benefited from its association with people.

Barn Swallow nests and droppings are messy. If you have a barn full of nesting Barn Swallows you already know this. If you don’t have a barn let me tell you about their nests. The nest is a cup made of straw and mud. When nest building swallows discover a mud puddle, a frenzy follows — twittering swallows descend from all over, scooping up mud in their bills. Up to a thousand beakfuls of mud may be needed to complete a single nest.

It is thought that swallows spend more time on the wing than any other songbird, flying the equivalent of 600 miles every day searching for food. As their name indicates, when they find food they swallow it. There is no biting, chewing, or stashing it for later; the food instantly goes down the hatch.

Swallows are not freeloaders; they earn their keep. Swallows pay the rent by eating huge quantities of insects, including beetles, bees, flying ants, horseflies and houseflies.

When food is plentiful young swallows grow quickly and are out of the nest in about two weeks. It is in their last few days in the nest that they make the mess that freaks people out. When the babies are small, the parents carry their droppings away in neat fecal sac packages. But as the kids get older and stronger, they just stick their rears over the rim of the nest and let it rip.

At the ebb of summer, day breaks with little help from the birds. A song sparrow may give a simple half-hearted song, a robin may warble overhead on the way to his daytime hunting ground, but few other birds have anything to sing about — they are preparing for the next phase of life’s cycle. Barn Swallows subsist almost entirely on insects, so they need to be long gone from here before cold weather arrives. As summer wanes, you can see groups of them sitting on power lines, feeding and flocking up for a long migration. By late August Barn Swallows will start to head out, flying by day so they can feed along the way. At sunset huge flocks of swallows descend into marshes to roost for the night. The sight of hundreds of birds diving into a marsh made early European colonists think that swallows spent the winter buried in mud. A pretty silly idea, but what would you expect from people who believed in witches and thought the world was flat?

At first light the flock will resume the long trip south. Covering hundreds of miles each day, the swallows are focused on reaching their wintering grounds in South America. Some birds go by way of Mexico and Central America, while others island hop through the West Indies. The island hoppers have the shortest flight but are also at the mercy of the weather. Hurricanes and tropical storms take a toll on them by battering them with wind and rain.

But the show is eternal: the world turns, the sun shines, the wind blows, the rain falls on seas and islands and continents. And Barn Swallows come back every April.