Farmland Swallows and Sparrows in August

     This morning, August 23, 2015, as I took a half hour drive through Lancaster County farmland from New Holland to Ephrata, I saw several flocks of post-breeding barn swallows, tree swallows and house sparrows along the rural roads I was on.  The mixed groupings of swallows by the scores and hundreds were lined up on roadside wires, perched on corn tassels, bare-ground fields and some of the roadways, or zipping through the air in pursuit of flying insects to eat.  Presumably, when the swallows' stomachs were full, the birds would perch to rest, digest and preen their feathers until hungry again.  The house sparrows were on the country roads to ingest undigested grain in horse manure, or weeds and fox-tail grass to eat the seeds of those plants.  When a vehicle approached, the swallows took to the air and the sparrows flew into the fields of tall corn and perched there until the vehicle passed by.  But soon all the birds returned to their original positions to rest or feed again.  Those swallows and sparrows made the trip to Ephrata more interesting.  
     These three species of small birds have adapted well to human-made cropland to their own advantage; hence their abundance everywhere in this county during summer of every year.  Milk is big business in this agricultural county and with that livelihood are thousands of cows, and horses, which are the power on the farms of plain people.  With those large animals comes manure, and millions of flies that were larvae in the manure.  And there are lots of flies on those large farm animals themselves.  Many of those flies are food for the swallows.  
     By mid-August, flies and other kinds of insects, including mosquitoes, had all summer to build up their numbers.  Those multitudes of flying insects are abundant enough to feed the hordes of swallows that had also increased their numbers during the same summer and are now gathering in the hundreds and thousands per flock in preparation to migrate south to find flying insects still in abundance beyond the reach of the insect-numbing cold of the northern winter.
     Another reason for the abundance of barn swallows and tree swallows in Lancaster County is that both species nest in human-made constructions.  Barn swallows hatch young in barns and under bridges while tree swallows raise offspring in bird boxes erected for them and bluebirds.  And, of course, in farmland, there is abundant flying insects all summer that feed those swallows.              
     Though plain in appearance for camouflage, house sparrows in their gatherings on the roads, roadsides and corn fields were interesting to experience, too.  They were on the roads and shoulders to eat seeds.
     House sparrows, too, rear youngsters in barns, and in crevices of any other human-made structure they can stuff grass into for a nursery.  This species adapted to farmland in Europe, long before they were introduced to North America.  And because they are seed-eaters and have adapted to sheltering in buildings and planted shrubbery at night, house sparrows are permanent residents wherever they may be.  They do not migrate.  
     Obviously, swallows and house sparrows are not competing for food.  Both groups of birds are pre-adapted for what they eat.  The swallows have thin beaks, but wide mouths, not for cracking seeds, but for netting insects on the wing.  The sparrows have thicker, stronger bills for cracking seeds, but the sparrows are not agile enough to snare a lot of insects in mid-air.
     Swallows and house sparrows are small, but big in numbers and impacts on farmland in much of North America every year.  People unknowingly have done well by them, by providing them with food and cover.  And these little birds add beauty and intrigue to farmland, particularly in summer.