The extensive cropland of eastern Lancaster County, Pennsylvania in winter is usually silent, except for the whining of the bitter wind in one's ears and the occasional raucous cawing of crows. And racing along with the wind, writhing sheets of snow hiss dryly over the fields and drift into ever-changing sculptures. Here and there green shoots of living winter rye and beige, dead corn stubble poke above the snow. But few trees and even less hedgerows break the continuity of the featureless shelterless fields.
The agricultural practices that scour Lancaster County farmland clean of tall vegetation, or any plants, must remind a few species of small, Arctic tundra birds, this far south in search of food sources for the winter, of the tundra they left behind. With a snow cover on it, that cropland must look particularly like the tundra to those migrant birds. And because these small, feathered ambassadors from the far north, including horned larks, Lapland longspurs and snow buntings are adapted to extensive, wide-open spaces, many of them winter on Lancaster County's human-made croplands, bringing a bit of the tundra with them.
These species of birds are camouflaged on wind-swept fields of bare ground or low vegetation, which make them virtually invisible to predatory hawks, and us, until those birds take flight. If we watch and wait in farmland that was harvested to the ground in autumn, we'll see groups of these little birds sweep up in quick, erratic flight, the larks lisping quietly and the snow buntings buzzing harshly and flashing large, white wing patches that make them resemble big snow flakes tossed about in the wind. Soon their wild, swift circling flight ends when the birds slide down into the wind and bound low to the ground on alternately beating and gliding wings. Abruptly they drop to the ground and immediately disappear among the snowdrifts and clods of soil exposed by the wind.
Each of these tundra species wintering here are either in pure flocks of their own or in mixed groups. Sometimes all four of the kinds of birds mentioned above are in the same flock, flying and feeding together. And all these species, except pipits, feed on weed and grass seeds and bits of corn lying in the fields. And all these species, except pipits, scratch through manure cast on top of the snow to get bits of chewed, but undigested, corn when seeds and corn kernels are buried in snow.
Horned larks are, by far, the most common of these small birds wintering on Lancaster County's extensive farmland. Many pairs of this kind nest on Lancaster County fields, which is risky for them because of the plowing and discing that can ruin clutches of eggs in their teacup-sized, soil nurseries dug by the birds themselves into the ground. The lark pairs keep trying from early spring into summer, until they get a brood fledged.
By autumn, many more horned larks come south, seeking food for the winter, thousands of which settle in Lancaster County. These migrants greatly bolster the numbers of their permanent resident relatives here.
Attractive birds in a plain way, horned larks are brown on top, which blends them into their surroundings. They have two black feather tufts on top of their heads, hence their name, and black bibs. But the rest of their face is yellow.
A few sparrow-like Lapland longspurs winter in flocks of horned larks, but not in groups of their own. This species is brown with streaking, has white outer tail feathers, and males each have a faded black bib.
Snow buntings are brown and white, which blends them into snowy fields. They sometimes mix with horned larks, but generally are in flocks of their own. However, buntings are not this far south every winter, but are here erratically.
These seemingly insignificant bird species add much interest and beauty to extensive, wind-swept fields in winter, a habitat they are well adapted to. But they are most easily seen after a snowfall when they are drawn to rural roads to eat tiny bits of stone that grind the seeds in their stomachs.
No comments:
Post a Comment