Saturday, February 9, 2013

Mark Twain Mergansers

The Salt River and its numerous tributaries drain a large part of northeastern Missouri, flowing eastward to join the Mississippi just north of Louisiana, Missouri.  In 1962, Congress authorized construction of the Clarence Cannon Dam on the Salt River, producing Mark Twain Lake just south of that famous author's birthplace (in Florida, Missouri).

Yesterday, my wife and I headed northeastward from Columbia to visit the Lake and its scenic basin.  Our journey was beneath a low, gray overcast through which multiple flocks of snow geese wandered in various directions, seemingly disoriented by the opaque sky.  Across the Glaciated Plain, red-tailed hawks lounged in barren trees, American kestrels hunted from powerlines and massive flocks of starlings swirled above the rolling farmlands.  A cold, north breeze swept across Mark Twain Lake where a mix of waterfowl fed in the shallows and a dozen or more bald eagles perched along the shoreline or fished on the open waters.  But the highlight of our visit was the large number of common mergansers, which were especially abundant on some of the north shore coves.

These large diving ducks, equipped with long, thin, serrated bills, are native to woodland lakes and rivers across southern Alaska, Canada, the northern tier of the U.S. and the Cascade, Sierra Nevada and Rocky Mountain corridors.  In winter, they migrate to large lakes, reservoirs and rivers throughout most of the United States where they gather in sizable flocks to feast on freshwater fish and crustaceans.  Unlike their red-breasted cousins, common mergansers are seldom found on brackish bays or estuaries.