Wintering Coastal Sandpipers

     At first they appear to be mechanical toys running up windy, winter beaches before incoming, ocean wavelets, and down those beaches after outgoing wavelets along the Atlantic Ocean coast of the Mid-Atlantic States.  Then we realize they are a little flock of sandpipers called sanderlings that search the sand of ocean beaches for invertebrates washed-in with incoming waves through winter.
     Four kinds of sandpipers commonly winter along the Atlantic Ocean shoreline, including sanderlings, purple sandpipers, ruddy turnstones and dunlin.  Each species has its own winter niche that it's well adapted to, which reduces competition with its relatives for invertebrate food, though some overlapping occurs.  Each species is camouflaged in its niche, protecting those sandpipers from peregrine falcons, merlins and other kinds of aerial predators.  And each kind of sandpiper raises four young in a brood on the high Arctic tundra. 
     Wintering sanderlings are light in color, which blends them in with the nearly white sand.  Little groups of them here and there along the beaches are entertaining and amusing to watch running up and down that sandy habitat in each bird's quest for invertebrates: Their black legs are blurs of motion as they run.  And their stout beaks jab repeatedly at invertebrates in the sand as they quickly follow wavelets sliding down the beaches and out to sea, leaving many invertebrates behind in the sand.  If sanderlings are approached too closely, their little groups spring up into the wind and swirl with the wind down the beach to a more private spot to chase receding wavelets for invertebrates.
     Purple sandpipers winter along the Atlantic seacoast where it is strewn with boulders at the water line and where human-made jetties of boulders project into the ocean at right angles from beaches to protect bathing beaches along the Atlantic Ocean.  This type of sandpiper is dark, which makes individuals of this species difficult to see on dark, wave-battered rocks and boulders.  This species, generally, winters on those rock formations as individuals or in small gatherings.  Each sandpiper clings tightly to the wet, plant-covered boulders as it forages for invertebrates among those rocks regularly splashed with ocean water.  Obviously, sanderlings and purple sandpipers compete very little for food, which allows both those species to live along ocean shorelines, in different niches.    
     Ruddy turnstones winter in small gatherings on pebbly beaches and among jetties where they hunt invertebrates.  This species sometimes overlaps with sanderlings and purple sandpipers in each of their niches.  Turnstones are brown on top and white below with white markings in the brown that are visible when the birds fly away from us.  And this species has the habit of turning pebbles over with its stout bill to look for invertebrates under them.
     Dunlin winter in the largest flocks of these seacoast sandpipers.  Their niche, mostly, is mud flats when the tide is out in tidal salt marshes along ocean inlets and estuaries.  They are brown above, which camouflages them on mud flats while they probe their beaks rapidly into the mud to pull out invertebrates.
     As the mud of mud flats becomes exposed, big flocks of dunlin sweep onto those flats like grain tossed across them, disappearing to the naked eye when landing on the mud.  Right away they poke their bills into the mud to snare invertebrates.  But if disturbed, their large gatherings swirl rapidly up into the wind and zip away over the flats to watch for a more peaceful place to land and feed.  
     These species of sandpipers add much beauty, joy and inspiration to the Atlantic Ocean shore in the Middle Atlantic States in winter.  Watch for them when visiting the seacoast during that harshest of seasons.