Vesper Sparrow

Pooecetes gramineus

Vesper Sparrow
Vesper Sparrow. Tim Lenz

Though the vesper sparrow has somewhat plain plumage, its beautiful song makes it more distinctive. These little brown jobs are more common in the western part of their range, but birders who know which field marks to note and what to listen for can easily add these sparrows to their life lists.

Common Name: Vesper Sparrow, Bay-Winged Bunting

Scientific Name: Pooecetes gramineus

Scientific Family:

Appearance:

  • Bill: Slender conical shape, pale with a darker gray-black culmen
  • Size: 5.5-6.5 inches long with 10-11-inch wingspan, long notched tail, deep belly
  • Colors: Brown, white, buff, cream, black, rufous
  • Markings: Genders are similar though males are slightly larger than females. The striped face shows a full white eye ring, plain white throat and a small pale auricular patch framed with a dark border with white below the border. The mantle is uniformly streaked brown and black, and the brown wings show two faint wing white or buff wing bars. The tail is dark with white outer feathers, and the underparts are creamy white or buff with thin dark streaking on the flanks and upper breast. The undertail coverts are plain white. In flight, a small rufous scapular patch is visible, but it is rarely noticeable on perched birds unless the wings are drooped and the plumage is relatively worn. The eyes are dark and the legs and feet are pale.

    Juveniles look similar to adults but show more extensive streaking on the underparts and less refined markings on the face.

    Foods: Seeds, insects, grain (See: Granivorous)

    Habitat and Migration:

    These sparrows have an extensive range that stretches across North America. They prefer drier grasslands, meadows and prairies, including weedy fields and scrub areas. They are also often found in recently burned areas as well as agricultural grain fields.

    During the summer, vesper sparrows can be found as far north as the southwestern corner of the Northwest Territories with their breeding range stretching to eastern British Columbia and east to southern Ontario, throughout Quebec and into Newfoundland and Labrador. Their range extends as far south as northern Nevada, Utah, northern Arizona, northwestern New Mexico, western Colorado and east through South Dakota and Iowa and into the northern regions of Illinois, Indiana and Ohio. Breeding vesper sparrows can also be found further east into New England, though the eastern populations are much sparser.

    During the winter, these sparrows migrate to southern California and throughout the southern United States as far south northern Florida, and their winter range reaches north to eastern North Carolina and Virginia. In the west, vesper sparrows winter as far south as central and southern Mexico.

    Vocalizations:

    These birds have a clear musical song that begins with 2-4 long, slow whistled notes followed by several buzzy trills and warbles. The typical call is a sharp chirp.

    Behavior:

    The vesper sparrow sings prolifically at twilight, at roughly the same time as Catholic vespers services, which earned the bird its name.

    This is not the only time these birds will sing, however, and when they are in a musical mood, they often perch on high, exposed branches so their song carries well, particularly during the breeding season.

    These are relatively solitary sparrows, though they will stay in small, loose flocks in fall and winter. While foraging, they occasionally join mixed flocks with other sparrow species. They often forage on the ground scratching for seeds and insects, and are apt to run or walk away from danger rather than take flight immediately.

    Reproduction:

    These are monogamous birds. After mating, the female builds a bulky cup nest on the ground underneath vegetation for concealment, using grass, weeds and small roots to build the nest and lining it with finer grasses and fur. The oval-shaped eggs are creamy white or pale green and marked with brown, gray or purple spots, streaks and splotches.

    There are 2-6 eggs in each brood.

    Both parents share incubation duties for 11-13 days, but the female generally does more incubation. If a predator approaches the nest, the female parent may use a broken wing distraction display to divert attention away from her vulnerable eggs. After the altricial chicks hatch, both parents feed the youngsters for 7-14 days, though toward the end of the nestling period the male may take over most of the tending while the female starts another brood. A mated pair of vesper sparrows may raise 1-3 broods each year.

    These sparrows are common hosts to brown-headed cowbird brood parasites. On rare occasions, vesper sparrows may hybridize with field sparrows, though such crossbreeding is not always confirmed.

    Attracting Vesper Sparrows:

    Leaving suitable singing perches available can help attract these birds so backyard birders can enjoy their melodies. A ground bird feeder with mixed birdseed, cracked corn or other grains is an ideal food source, and bird-friendly landscaping that includes seed-bearing flowers will also tempt vesper sparrows. They are particularly fond of dust baths, and will use a suitable dusting area frequently. If birders cannot attract these sparrows, they may still be able to see them in appropriate habitats, particularly along rural roadsides and weedy agricultural fields.

    Conservation:

    These sparrows are not considered threatened or endangered in any way, but their population is slowly declining due to habitat loss. General development, agricultural mowing and overgrazing all take away the habitat vesper sparrows rely on.

    Similar Birds:

    • Savannah Sparrow (Passerculus sandwichensis)
    • Henslow's Sparrow (Ammodramus henslowii)
    • Song Sparrow (Melospiza melodia)
    • Brewer's Sparrow (Spizella breweri)
    • American Pipit (Anthus rubescens)
    • Sky Lark (Alauda arvensis)

    Photo – Vesper Sparrow © Tim Lenz