SKIMMERS AND OYSTERCATCHERS

     When I was a boy, for a few years my family rented a house for a week each year in Margate City, New Jersey to experience the ocean and beach.  During the long, summer evenings, however, I walked to Egg Harbor to see the beauty of it.  While there, I saw one or two gull-sized birds, silhouetted black before the sunset, flying back and forth just above the water's surface, each one with its lower mandible an inch in the sky-reflecting water and cutting it as they strongly, and gracefully, beat their wings in flight.  I later learned those fascinating, beautiful birds, that I enjoyed seeing, were black skimmers that were catching small fish that bumped their lower mandibles poked in the water.

     Black skimmers and American oystercatchers are unrelated birds that have similar characteristics, including living and nesting along the Atlantic Coast.  Both species rest on beaches and mud flats.  Both hatch young in shallow scrapes in sand on sandy islands, beach dunes, and piles of dredged-up soil islands.  Some individuals of each species fly north a short distance to their nesting areas.  And late in summer some of both kinds drift south a bit for the winter.  Adults of both kinds are black on top and white below with long, vertically flat beaks that have unique roles.  Both species hatch a few fluffy, camouflaged young that leave their nurseries at an early age.  The chicks of both kinds are fed by both their parents until able to fly and hunt for food for themselves.  Unfortunately, both species are subject to their nests being flooded some years, gulls and other predators eating their eggs or small young, human and dog intrusions, and habitat loss.

     The most interesting feature of each species is its unique beak.  The lower, red and black mandibles of skimmers' bills are an inch longer than the upper mandibles, a unique adaptation for snaring small fish at the water's surface.  When skimmers feel a fish bump their lower mandibles, they snap their beaks shut on it and swallow it whole and head first.  No other kind of bird fishes in that way.

     The handsome oystercatchers have totally-red, vertically-flattened, knife-like beaks they use to slip between the protective shells of molluscs to snip the muscle that holds the shells together.  When the shells are open, oystercatchers ingest the meat inside.  Again, this is a unique way of getting food that no other bird species duplicates.  Obviously, there is no competition for food between the attractive skimmers and oystercatchers.    

     Skimmers are tern-like and related to terns and gulls.  And like many of their relatives, skimmers attempt to raise young in colonies along sea coasts.  Skimmers also fly in small groups, often turning this way and that in unison, which is a joy to see.

     Because of limited nesting habitats, and losses some years, skimmers and oystercatchers are limited in numbers.  There are about 65,000 skimmers in North America and about 43,000 oystercatchers in North America.  But these striking birds are a pleasure to experience, wherever they may be noticed.    

             

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