Thursday, December 1, 2016

Winter Flock Birds

     Every winter day in the farmland of Lancaster County, Pennsylvania, we see large, exciting flocks of noisy American crows in fields and gathering at their overnight roosting place at Park City Mall outside Lancaster City.  These crows raised young in the forests of Canada and are here in winter because of more abundant food, including corn kernels in harvested fields, acorns on lawns, road-killed animals, dead livestock in fields and tidbits on parking lots and in dumpsters, all of which are unwittingly provided by human activities.
     Several other kinds of adaptable, abundant birds also form big, interesting flocks in human-made habitats where they roost and/or feed, and in the air, in winter.  These birds include ring-billed gulls, mallard ducks, Canada geese, starlings, rock pigeons, house sparrows, mourning doves, American robins, horned larks and two species of vultures.  All these species shelter at night in different places.  All are permanent residents as species here, except the crows and gulls.  And all are entertaining, particularly in the air.
     Having nested along the Great Lakes, St. Lawrence River and ponds in western prairies, ring-billed gulls winter along the Great Lakes, the Atlantic, Pacific and Gulf coasts, and along Chesapeake and Delaware Bays, Delaware, Hudson, Potomac and Susquehanna Rivers and many inland, human-made lakes in the eastern United States, including in Lancaster County.  Wintering ring-bills also hunt fish, scavenge edibles and roost at night in those watery habitats.  And they scavenge from landfills, dumpsters and parking lots. 
     But flocks of ring-bills are most majestic when flying to or from their feeding areas in winter mornings and mid-afternoons.  They fly swiftly in V's, long lines or loose congregations, gang after gang, one after another, along aerial highways, steadily and silently, until they reach a feeding place or their watery refuge for the night.  Upon reaching their destination, the various flocks swarm round and round and intermingle by the hundreds, before landing on land or water.
     Mallards and Canada geese nest near water in Lancaster County, as elsewhere across most of North America and winter mostly on human-made impoundments, large and small.  Through winter, they rest on the still water, but feed in harvested corn fields and winter rye fields.  Flocks of these related water birds are most stately when in flight and silhouetted black against red sunsets of winter evenings.  Both species take off into the wind from the water, group after group along an invisible road through the sky.  The mallards take flight with whistling wings while the Canadas honk noisily and with a slapping of webbed feet on the water before becoming airborne.  Upon arriving at a feeding field, flying gangs of both species circle the field to watch for danger.  When seeing none, they come down to the ground, angling into the wind, one group after another, until all are on the ground and feeding.  Sometimes in winter I've watched these birds dropping to fields into drifting snow at sunset.  One second they were visible, the next they were not, then they suddenly reappeared.  And, meanwhile, that blowing snow was pink, from the sunset, and looking like the farmland was on fire.
     Gatherings of starlings, rock pigeons and house sparrows, all originally from Europe, and native mourning doves, the pigeons' little cousins, all feed on grain and weed and grass seeds in fields the year around, including winter.  The brown sparrows and doves are camouflaged on the ground and hard to see.
     Starlings move about in great flocks that draw pictures in the sky as they swirl and turn this way and that in unison, without collision.  These birds spend winter nights perched on buildings and in planted patches of evergreen trees that block winter wind.
     Doves also spend winter nights in coniferous trees, but pigeons perch overnight in barns, under bridges and on ledges of city buildings.  House sparrows nestle into dense shrubbery and crevices in buildings during winter nights.
     Not all American robins migrate south for the winter.  Some groups of robins stay north and feed on crab apples and berries during winter days.  And these relatives of thrushes spend winter nights in the protective embrace of coniferous trees in suburban lawns.   
     Gatherings of horned larks fly low across fields harvested to the ground.  Their flight is bouncy as if bobbing over invisible wavelets, then suddenly disappears as the birds land on the ground where they are camouflaged. 
     Horned larks nest on those fields, and winter on them, when they feed on weed and grass seeds and hunker down overnight among clods of soil or whatever vegetation they find in fields.  And larks, and all other birds in this essay, except robins and vultures, feed on bits of chewed, but undigested, corn in livestock manure spread on top of snow in the fields.
     Gangs of turkey vultures and black vultures, sometimes in mixed gatherings, scavenge dead chickens and other deceased livestock dumped into the fields, including in manure strips.  Turkey vultures are usually the first to notice dead animals because of their good sense of smell, a sense that is not so well developed in black vultures.  Vultures roost overnight in tall conifers, mostly in wooded valleys that block cold winter wind.
     These winter flock birds generally are noticeable in Lancaster County cropland, if one looks for them a little.  And these species of birds are entertaining to see going about their daily business during those cold, bleak days of winter.  Those birds can be inspiring. 
         
    
          

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