Wintering Coastal Sandpipers

     Many of us see sandpipers along the Atlantic Coast in spring and late summer, which are their times of migrations north and south respectively.  But some of us don't know that while most sandpiper species continue father south for the winter, at least a few kinds, including sanderlings, dunlin and purple sandpipers,  winter along the Atlantic Coast in the Middle Atlantic States, including in New Jersey, Delaware and Maryland.  And each type has enough numbers in winter here to be noticeable to even casual observers along the ocean, if those people know where to look.
     Sanderlings are the kind of sandpiper one sees in little groups running up and down sandy beaches along the Atlantic Ocean itself.  When waves slide up the beaches, gatherings of sanderlings run up  the beaches ahead of the incoming water.  But when each wave rolls down the beach to the ocean again because of gravity, the sanderlings quickly follow it to pick up and consume any tiny invertebrates that were stranded on the sand.  Sanderlings are entertaining to watch.  And this is the only sandpiper species that behaves in that way, on a sandy beach habitat in winter.     
     Sanderlings have pale-gray, winter plumages that allow them to blend into the color of the sand and be hard to see when they are still, which protects them from predation.  And when they run up and down the beaches, their black legs move rapidly, almost as if they were on wind-up toys.
     Dunlin flocks by the hundreds, or in the thousands, feed on invertebrates in the mud of mud flats that are exposed and unfrozen because of receding water when the tide is out.  Dunlin are gray-brown on top and lighter underneath for camouflage on the mud.  They are most likely to winter in salt marshes back from the ocean and beaches.  There they are protected from cold, winter wind by the tall grass of salt marshes as they ingest invertebrates.
     Purple sandpipers have dark feathering which camouflages them on the boulders of rugged seacoasts and human-made rock jetties.  Jetties jut into the ocean at right angles to the beaches to protect those sandy beaches, where sanderlings roam, from wave erosion.  And purple sandpipers found those jetties to be good substitutes to the rocky shorelines they traditionally winter on.
     Purple sandpipers walk about on the boulders of jetties in their search for invertebrates to ingest.  But these sandpipers are often overlooked until they move along the rocks or fly from boulder to boulder to new feeding spots because of their camouflaging plumages.
     Notice how each kind of wintering sandpiper is in a particular niche- beaches, mud flats or boulders.  By spreading into different habitats, these related birds reduce competition for food among themselves through winter.  And notice, too, how each species takes on the color of its environment.  
    When along the Mid-Atlantic seacoast in winter, it might be interesting, and fun, to look for these kinds of sandpipers, and other species of that family, in the coastal habitats mentioned here.  These sandpipers, gulls and other kinds of water birds certainly liven the seacoast in winter.