Adult vesper sparrow upperparts are streaked with black, tan, and gray. The head is finely streaked with black, with a white eye ring. The brown cheek patch is bordered in front by a white moustache line that continues below and around the back lower side of the patch, forming a shallow whitish U. Underparts are finely streaked with black on the breast and sides, rarely with a central spot. Outer tail feathers are white and easily seen as the bird flies away. The beautiful song begins with two slurred whistles, then two higher notes, and ends in a jumble of descending trills: come-come, here-here, all-together-down-the-hill. The song resembles that of the song sparrow but has two instead of three introductory notes.
Similar species: Song sparrows lack a distinct white eye ring; they also lack the white outer tail feathers. The Savannah sparrow’s pale eyebrow helps to distinguish it; it also does not have a white eye ring, nor does it have white outer tail feathers. Lark sparrows are found in similar habitats in northern Missouri, and they also flash white in their tails as they fly; they have a brown and black, rounded-tipped tail with white corners, while vesper sparrows have a slightly notched, all-dark tail, with the two outer tail feathers mostly white, edging the sides of the tail. The horned lark is also common in the same areas; it is about an inch longer, appears slimmer in profile, and has a black tail with white outer tail feathers.
Length: 6¼ inches.
Statewide. The southern third of Missouri is in its wintering range, and our northern counties are in its breeding range. In between, it is most likely to be seen during migration.
Habitat and Conservation
In summer and during migration, vesper sparrows usually inhabit wide-open agricultural land, far from trees. In northern Missouri, look for them in crop ground and large fields in forest openings.
Forages on the ground for grass, weed, and grain seeds and insects. They typically scratch the ground with both feet at once. As with many other birds, during nesting season insects form a greater percentage of the diet, as the growing young require additional protein. This comes in the form of grasshoppers, beetles, cutworms, armyworms, and so on.
As a migrant, uncommon statewide, usually seen foraging in open fields and plowed ground away from shrubs and trees. As summer breeding resident, rare in northern Missouri, in crop ground and large fields in forest openings, and casual in southern Missouri; as winter resident, casual in the south, accidental in the north. The vesper sparrow is the only member of its genus; its closest relative may be the lark sparrow, which is also the only member of its genus.
Present in Missouri from mid-March through the end of November, with numbers peaking in late March and early April, and from early October through early November. Nests are loosely woven of grasses, fine weeds, and other materials, and are positioned on the ground. A clutch comprises 2–6 eggs. The male’s song is especially noticeable in late afternoons and evenings (hence the name “vesper sparrow), but during courtship and breeding season, the males sing at any time of day.
A writer once described the song as a “simple little expression of quiet thankfulness and very beautiful contentment. . . . [with] an especial sincerity and spontaneity. . . . It blends perfectly . . . with the spirit of the evening and the advancing shadows.” In the early 20th century, many naturalists “imbued” birds with human sentiments. Though rarely technically accurate, this approach can inspire people, especially children, when they are first starting to learn about birds.
As with many other birds, vesper sparrow populations are declining; over the last 50 years, they have decreased nearly 40 percent. They require open, grassy habitats, and agricultural practices such as large-scale tilling, liberal use of chemicals, and early or too-frequent haying, contribute to the decline. It is state-endangered in several states in the east, where farmland is being displaced by residential and commercial development.