Certain species of farmland birds noticeably change their habits to get food when there are several inches of snow on the ground here in agricultural Lancaster County, Pennsylvania. Three cropland niches in particular demonstrate where and how those birds get food when snow covers the birds' normal feeding niches.
Snow plows remove snow from country roads, and some of the roadsides down to the soil. That plowing bares seeds and tiny stones that flocks of sparrow-sized horned larks, mourning doves, rock pigeons, savannah sparrows, house sparrows, American crows and other seed-eating bird species consume along the edges of rural roads when seeds and grit in the fields are buried by snow. Normally all these birds feed on seeds and grain in the larger fields of this area, and, being camouflaged except the crows, are not obvious to us. But these same birds flock to rural roadsides after a snowfall to eat seeds, and teeny stones that help grind those seeds in their stomachs until the snow melts and their normal food sources are again available to them. Then we readily see them right along those roadsides.
Horned larks are, by far, the most abundant of these species in winter farmland. Flocks of a few score to over a hundred larks each are easily seen along the roadsides after a snowfall. The larks, and the other bird species, rise up ahead of passing vehicles, but soon settle along the roadsides again to feed on seeds and grit. These birds are desperate for food and have no time to waste flying about.
Horned larks are striking birds in a plain, camouflaged way. They are light-brown on top to blend into bare-ground habitats. And they have handsome black and yellow face patterns.
Some groups of horned larks have Lapland longspurs and snow buntings among them. Both those species nest on the Arctic tundra, and come south some winters to find seeds to eat.
Some winters snow buntings are here in large numbers and form beautiful, intriguing flocks of their own on large, snowy fields where they are invisible until they fly low over those snow-covered fields or are along country roads ingesting seeds and grit. The beautiful snow buntings are white and brown in winter, which blends them into the fields.
Chewed, but undigested corn kernels in animal manure spread in rows by manure spreaders on top of snow in fields is a handy source of abundant food for seed and grain-eating birds, including the ones discussed above, and mallard ducks, Canada geese and tundra swans. Those birds scratch, shovel and peck through that animal waste to get the corn, which sustains them until the snow melts away and their more normal sources of food are again available to them.
Shallow brooks and small streams running through cow pastures in this county are life savers to a few kinds of wintering birds when snow is on the ground. The running water keeps the muddy edges from freezing or being covered by snow. Wilson's snipe normally winter along those meadow waterways where they rapidly probe their long beaks like sewing machine needles in mud under shallow water to capture aquatic invertebrates. These inland sandpipers are well camouflaged in their exposed niche and are not usually seen until they fly.
Meanwhile, killdeer plovers, wintering American pipits from the tundra, and local song sparrows feed in the fields, until their foods of invertebrates and seeds are buried under snow. Then those three species of brownish birds join the snipe at brooks and streams to capture and ingest invertebrates from the mud and running water.
The sparrow-sized pipits constantly bob up and down as they walk along the shores of those small waterways to get invertebrate food. That bobbing is a mimicry of objects bouncing in the current so the pipits are undetected by predators, particularly small hawks.
These are a few ways wintering birds in this area cope with snow on the ground that blocks their getting their normal foods. Those birds adapt to other food sources until the snow melts away and their usual foods are available to them again.
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