Birds of Leelanau: The Field Sparrow
The Field Sparrow's most distinctive feature may be its song, which always starts with clear, somewhat plaintive notes that gradually become compressed into a trill. An apt analogy often given is that of a bouncing ping-pong ball. Its second distinctive feature is its bright orange bill. The literature reveals its size as varying from 5 to 5 3/4 inches.
Sexes are similarly adorned with a white eye ring; a rusty crown, ear patch, and eyeline; dark eyes; a face that is buff in the winter and gray in the summer; a buffy breast; a somewhat white belly and undertail coverts; brownish wings with two, white wing bars; pink legs; a slim, forked tail; and a rusty, darkly streaked back.
It is not found in freshly tilled or mown fields but rather in old fields overgrown with weeds and brush, open, bushy woodlands, young evergreen tree plantations, deciduous forest edges, and recently cut forest lands. It is not found in the immediate vicinity of human homes.
It breeds in habitat also sought by Song Sparrows, Brown Thrashers, and/or Eastern Towhees. It is described by Graf as a confirmed breeder but an uncommon summer resident and very uncommon transient of Leelanau County.
Males of this species tend to return to the same breeding territory each year. The male sings until it finds a mate, after which it sings just occasionally,
The female selects the nesting site, often locating the first nest on or very close to the ground. The 2nd nest is usually built higher. Over a period of 4-5 days, she carefully fashions a cup shaped nest of grass and forbes which is then lined with fine materials. She lays 3-5 eggs.
Incubation takes 10-17 days. The female does most of the brooding with the male occasionally feeding the incubating female. Once hatched, the young fledge in 7-8 days. Both parents feed the young although the male may do most of the feeding while the female builds the second nest. Usually there are 2 broods but occasionally three.
This species is frequently a cowbird host. If a cowbird is a observed by the nest-building female, work on the nest ceases until the cowbird leaves. Nests parasitized by cowbirds are often abandoned.
The diet of this species is made up of seeds and invertebrates gleaned from the ground and near the ground foliage. Nestlings are fed almost 100 % macro-invertebrates.
Young from the first broods gather in small flocks of 10-12 individuals tolerated by the territorial males. Larger postbreeding flocks roost in small trees and shrubs prior to migration.
In Michigan, Field Sparrow presence decreases the more northerly the location. There seems to be a gradual increase in numbers in the northern lower peninsula counties and in the UP as population density and concurrent deforestation in those areas increases. In recent years, though its summer range in the state is growing, its overall numbers seem to be in decline. The appearance of this species on Christmas Bird Counts in Michigan is rare.
The literature indicates that Field Sparrows breed from eastern Montana eastward to southern Quebec and southern Maine, and southward to central Texas and northwestern Florida. They winter from Kansas, Illinois, Pennsylvania, and Massachusetts southward to very northeastern Mexico and northern Florida.
~bob c.