Tuesday, June 2, 2020

SPRING ON THE MISSISSIPPI FLYWAY

     I've seen several kinds of water-loving birds along the Mississippi River and one of its backwaters in Wisconsin during the spring of 2020.  I saw most of those birds on extensive mud flats and shallow, sky-reflecting channels amid marsh-and-tree-covered islands, all of which are bordered on both sides by tree-covered hills.  All this I saw through a live camera mounted along the river and our home computer screen. 
     Spring is born from the chilly womb of winter.  Several each of bald eagles, ring-billed gulls, Canada geese and mallard, common goldeneye, bufflehead and common merganser ducks winter along the Mississippi, as long as some water remains ice-free.  The eagles and gulls catch and scavenge fish.  The magnificent eagles roost overnight on trees on the islands, while flocks of gulls spend winter nights on the flats. 
     The geese and ducks spend winter nights bobbing on the water, or sitting on ice.  The majestic geese, and mallards, "tip-up" to feed on vegetation in the shallows and nearby marshes.  And the related, similar-looking goldeneyes and buffleheads dive under water from the surface to eat small mollusks and crustaceans, while mergansers catch small fish.  Obviously, these water birds can live together in harmony because they have different foods.
     By early March, certain kinds of migrating birds stop for a few weeks on this part of the Mississippi to rest and gain nourishment.  Hundreds of similar-looking lesser scaups and greater scaups, which are related bay ducks, dive underwater from the surface to ingest aquatic vegetation, mollusks and crustaceans.  But soon they migrate farther north and west to their breeding territories around the "potholes" in the mid-western prairies of Canada and the United States to raise young.
     Scores of stately, north-bound tundra swans rest among the mud flats and shallow channels where they dine on underwater plants by reaching their long necks down to them.  Everywhere the swans go and everything they do is highlighted by their reedy, whistling calls that identify them.  And by late March they are on their way north to the Arctic tundra where they will raise cygnets. 
     Flocks of tall, stately sandhill cranes roost at night on some of the mud flats and shallows in the Mississippi in April. There they rest between feeding forays on the flats and in nearby marshes.  And all the while their gutterel, rolling trills precede the seeing of them.  And, like the swans, the cranes soon push farther north to the tundra of Canada, Alaska and eastern Siberia to raise one or two young per pair.     
     Scores of handsome American white pelicans, and double-crested cormorants, both fish-eaters, are on the Mississippi in Wisconsin in April.  These species co-exist because they have different ways to catch fish.  Cormorants dive under water from the surface and search deeper waters for their finny prey.  White pelicans, however, work together by dipping their large beaks, like nets, at the same time in shallow water to scoop up fish.  These pelicans raise young by fish-filled, Canadian lakes. 
     By April, too, gadwalls, green-winged teals, blue-winged teals and northern shovelers, all species of small ducks, are in the shallows among the marshes and mud flats of this part of the Mississippi.  There these kinds of pretty ducks tip-up to consume aquatic plants from the bottoms of the marshes and shallows.  All these species, too, hatch ducklings in the pot-holes of American and Canadian mid-west prairies.  
     Many striking red-winged blackbirds are in the island marshes along the Mississippi to raise young among the tall grasses.  Male red-wings are black all over, with red shoulder patches they raise when singing from swaying grasses to attract mates and reject rival male red-wings.  Each female red-wing attaches her grassy nursery to grass stems a few feet above the water or soil of a marsh.
     A few each of great blue herons and great egrets stop along the shallows of the Mississippi in Wisconsin to catch fish.  They are entertaining to watch stalking their prey in the shallows. 
     Early in April, loose flocks of stream-lined, north-bound Bonaparte's gulls and tree swallows sweep swiftly over the Mississippi, often at the same time, but not together.  Both these lovely species of migrating birds are entertaining to watch swooping gracefully over the river after flying insects, and small fish and other tidbits off the water in the case of the gulls.  Those gulls are small and dainty for their role in life.
     Tree swallows nest in tree cavities and bird boxes.  Bonaparte's hatch young in twig cradles they make on spruce trees near lakes in Canada's boreal forests, something other kinds of gulls don't do.
     In May, flocks of migrating shorebirds of several kinds trot over the mud flats and in shallows after small invertebrates to eat.  Most of them are so small and well camouflaged that they are often tough to spot on the mud. 
     Some of the more commonly seen migrant shorebirds on Mississippi flats and shallows include least, semi-palmated and pectoral sandpipers, dunlin, greater and lesser yellowlegs, ruddy turnstones, semi-palmated plovers and avocets.  But by the end of May, most of these beautiful shorebirds are on their way to the Arctic tundra to hatch offspring.       
     The flats and shallows of parts of the Mississippi River in Wisconsin are entertaining with migrating birds from early March to the end of May.  And the most convenient way to experience these birds is through the live camera and a computer screen right at home.
      
              

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