Monday, March 16, 2020

Inland Shorebirds in Spring

     About sunset one March evening when I was about twelve, I was walking through a plowed field in Lancaster County, Pennsylvania farmland and suddenly flushed up a robin-sized, brown and white bird that had an orange tail.  It flew up right in front of me and called loudly, startling me.  I later learned that the bird was a killdeer plover that was either migrating north or preparing to nest in that bare-ground field.
     I like February, March and April here in southeastern Pennsylvania because of the excitement of longer periods of daylight each succeeding day, warmer weather, on average, the blooming of early flowers, the migration of certain kinds of birds and the courting and nesting of other bird species.  Killdeer plovers, Wilson's snipe and American woodcocks are inland shorebirds that winter here in limited numbers.  But many other individuals of each kind migrate into this area and beyond during March, bolstering the numbers of each of these beautiful, interesting species here, and in the northeastern United States. 
     The related killdeer, snipe and woodcocks all live in moist, bottomland habitats, but in different niches, which makes them distinct species.  However, being cousins to each other, they all have certain traits in common.  They all consume invertebrates off the ground.  Each female of all species lays her four eggs in a shallow cradle on the ground.  The young of all species hatch fully fuzzed, open-eyed, and ready to run and feed themselves within 24 hours of hatching.  And the eggs, young and adults of each kind are camouflaged, blending them into their surroundings, which hides them from predators.  I must confess, I can not see any of them standing still in the open in their natural habitats.  I can only spot them when they move across the ground, or fly.
     Killdeer summer and raise young on gravel bars along streams, creeks and impoundments, gravel parking lots and railroad beds, bare-ground fields, short-grass lawns and meadows, and similar, open habitats.  Camouflage is necessary in such shelter-less niches these birds evolved in.
     But killdeer also have another defensive strategy- the broken-wing act.  If a predator gets near a killdeer nest or foraging young, the adults flop about like they are crippled, which lures predators to those parents and not the eggs or chicks.  When the predator is led far enough away from the young, the adults suddenly take flight, leaving the predator in confusion, while the youngsters are safe, for the moment at least.
     Snipe nest farther north than southeastern Pennsylvania.  But some winter here and migrate through this area.  Snipe frequent the edges of brooks and streams in cow pastures, where they probe their long beaks into mud under shallow water to pull out and ingest worms and other kinds of invertebrates.
     Snipe are beautifully feathered in brown and darker streaking which camouflages them.  It takes me a bit of looking through binoculars to finally spot some of these inland sandpipers.
     But the most intriguing inland sandpiper in this grouping is that crepuscular recluse with a long "nose", the American woodcock of bottomland woods and thickets.  Through the last several years, I have seen many courtship displays of male woodcocks performed before the soft-pink of spring sunsets and bare, deciduous trees.
     Soon after sunset, most every evening through March and April, each male woodcock flies out from his ground retreat in a bottomland woods or thicket and lands on a bare-ground spot in a field or other open habitat.  There he stands with his long beak on his chest and vocally "peents" for up to a minute or more.  Then he takes off in spiral flight into the darkening sky, higher and higher, while a special feather on each wing twitters rythmically.  At the height of his climb, he vocally sings several bubbling notes, then dives to the ground, levels off and lands on his bare spot of soil to repeat his performance again, and again.  Only hunger or female woodcocks willing to mate stop his interesting courtship displays for the evening.  But each male woodcock will be back displaying the next
evening, weather permitting.   
     These inland shorebirds help make southeastern Pennsylvania more interesting each spring.  The challenge, of course, is finding them.              

No comments:

Post a Comment