SPRINGHOUSE FARM JOURNAL
By Heather Lovett
Walking up the hill near my house one cold winter morning I came upon a curious scene by the side of the road. A group of small birds had gathered at the edge of a snow-covered field, and they seemed to be performing a strange ritual or dance, flying a few feet straight up in the air and dropping down againup and down, up and down, as if bouncing on a tiny trampoline.
As I watched through my binoculars from a short distance away, it soon became clear what the birds were up to. They were flying to the top of tall grasses sticking out of the snow and landing near the seed heads, letting their weight bend the stems to the ground where they could easily pluck out the seeds.
I marveled at this clever, energy-efficient foraging technique, a system that must be especially useful on snowy days when seeds are harder to come by. From their size and color I later determined the birds were probably field sparrows, a species known for harvesting seed in this manner.
Field sparrows are small, sociable birds, slim and long-tailed, with a grayish, buff-washed breast, a rusty crown, and a brown back patterned with light and dark markings. The most striking feature is an orangey-pink bill (less colorful in winter), almost unique among sparrows, followed by a white eye ring, which gives the bird an appealing, wide-eyed expression.
Although their name implies an affinity for farmland, field sparrows prefer a messier habitat than a typical, well-groomed hayfield. They like to nest in abandoned pastures filled with weeds, brambles and low-growing shrubs, where they blend in so well with their surroundings that for many years I knew them only by their songa sweet, plaintive trill that speeds up as it goes along, sometimes on the same pitch, sometimes rising or falling.
Lang Elliot, author of "Music of the Birds," claims the field sparrow’s song is among "the finest examples in the bird world of musical accelerando." He elaborates with a quote from the ornithologist Edward Forbush (1858-1929), who described it as "a pensive strain, often varied; (that) usually begins with a few slow, high, clear, prolonged slurred notes, then accelerates, and finally trails off diminuendo in rapid repetitions, fading as it ends."
The song has been likened to a young canary’s trill, a bouncing ping-pong ball, and the tinkling of a spoon on a saucer, but my favorite metaphor comes from Henry David Thoreau, who on July 16, 1851, wrote in his "Journal" "The rush sparrow jingles her small change, pure silver, on the counter of the pasture." (Rush sparrow is an old name for the bird; others are field bunting and huckleberry-bird.)
Early in the spring I hear field sparrows on my morning walks, the males singing their claims from hidden perches as they divvy up the old abandoned pasture near the top of the hill. Their music continues sporadically throughout the summer, often extending into the evening when most other birds are silent.
Thoreau noted this habit of singing at dusk, calling the field sparrow "Nature’s minstrel of serene hours" (April 25, 1841). Almost 20 years later he wrote of being serenaded as he planted pine trees in a field at Walden: "as the walls of cities are fabled to have been built by music, so my pines were established by the song of the field sparrow" (April 22, 1859).
Field sparrow nests are frequently disturbed by predators or parasitized by cowbirds, prompting the females to start overand over and overup to seven or more times a season. (One female in Illinois reportedly built a record 10 nests in a single summer.) Each pair usually succeeds in raising two or three broods a year, the first in a nest built on or near the ground and the later ones higher up in a tree or shrub.
In spite of such determination the population of field sparrows appears to be declining. This is most likely due to loss of habitat, as overgrown brushy fields are either cleared and developed or in some cases allowed to revert back to forest. The birds seem to prefer the in-between stage, which makes their situation more precarious, since abandoned fields (at least in the Northeast) rarely stay that way for long.
Over 90 percent of a field sparrow’s winter diet is seeds, yet it rarely visits feeders, depending instead on a certain amount of untidiness in the landscape. I’m grateful that Hopewell Township still has a fair amount of ragged and weedy places where birds can nest and feed, for if every lawn were neatly mowed right up to the road, and all vegetation carefully pruned and mulched to perfection, feeder-shy birds would be hard-pressed to find anything to eat in winter.
I don’t know how much longer the old pasture on the hill will be attractive to field sparrows, since the young trees and shrubs are getting taller every year. Unless something changes it will grow back into a forestnot a bad thing, of coursebut if this happens I hope the sparrows find another untidy field nearby to suit their needs, for I would sorely miss their musical accelerandos and diminuendos in the spring.
References:
Elliot, Lang. "Music of the Birds." Boston: Houghton Mifflin Company, 1999.
Kaufman, Kenn. "Lives of North American Birds." Boston: Houghton Mifflin Company, 1996.
Thoreau, Henry David. "Thoreau on Birds: Notes on New England Birds from the Journals of Henry David Thoreau." Edited by Francis H. Allen. Boston: Beacon Press, 1993.
Heather Lovett is a a resident of Hopewell Township.