Flooded Meadows and Fields in Spring and Fall

     A variety of swallows and shorebirds migrate through Lancaster County, Pennsylvania every spring and fall.   Several individual migrants of both families of birds feed on invertebrates in and just over flooded meadows and fields during those times. 
     Heavy or prolonged rain fills parts of those open, human-made habitats, forcing invertebrates out of the soil to avoid drowning.  Those tiny critters become food for migrant swallows and shorebirds.
     I drove by a large rain puddle in a farmland pasture one morning early in May.  A few kinds of shorebirds, including several each of lesser yellowlegs, least sandpipers and killdeer plovers, a greater yellowleg, and a few each of pectoral sandpipers and solitary sandpipers were wading in the shallow water or walking along its muddy edge.  The sandpipers and yellowlegs were probing into the mud under water while the killdeer picked up prey from the surface of the water and mud, thus reducing competition for food a bit. 
     A pair of mallard ducks were shoveling up inundated plants, roots and all, from the water.  And a  male red-winged blackbird ate invertebrates from the mud, vegetation and water.
     But what struck me the most about that drowned meadow was that I never saw so many barn swallows and tree swallows zipping back and forth over one temporary puddle in a pasture or field as I saw at this one.  I could see the orange bellies of the barn swallows as they flew and the white ones of the tree swallows as both species coursed swiftly, abruptly turning this way and that without collision with their fellows.   
     Those scores of swallows, careening rapidly just over the water to catch the apparent abundance of flying insects, were entertaining the several minutes I was there watching them go about their business.  Each swallow repeatedly dashed over that meadow pool, swung out and around and back over the water again, snaring prey as it flew.
     I continued to watch the swallows feeding until most peeled away, probably with full stomachs, to perch somewhere and rest and digest.  The shorebirds, however, continued to feed as I left.
     This county received heavy rain during the end of July and a temporary pond formed in a depression in a meadow that is purposefully flooded in winter by farm people for ice skating.  I drove by that puddle early in August and saw a variety of birds taking advantage of that temporary, quarter-acre  body of water. 
     Several Canada geese, a hen mallard and three ducklings and a small flock of starlings were at this pool.  The geese were eating flooded grass while the ducklings and starlings ingested invertebrates.
     Meanwhile, several each of southbound barn swallows, tree swallows, bank swallows and purple martins, which are another kind of swallow, swooped low over the water to catch flying insects, again being quite entertaining.  And several migrant lesser yellowlegs, and a few each of southbound least sandpipers, pectoral sandpipers and killdeer, and a solitary sandpiper probed in the mud to seize invertebrate food.  Interestingly, the starlings were poking their beaks into the mud like the shorebirds to get invertebrates.
     The most intriguing part of these birds feeding on invertebrates trying to escape high water is that they were doing so on human-made, seemingly barren habitats.  Creatures that adapt to how we change the environment have a future.  And, of course, the swallows and shorebirds were not competing for food which allowed both groups to get ample food on those built environments.  The beauties and intrigues of nature are everywhere on Earth.