Though the vesper sparrow has somewhat plain plumage, its beautiful song makes it one of the more distinctive members of the Passerellidae bird family. 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. This fact sheet can help you discover all you need to know to quickly and confidently recognize the vesper sparrow.
- Scientific name: Pooecetes gramineus
- Common name: Vesper Sparrow, Bay-Winged Bunting
- Lifespan: Up to 7 years
- Size: 5.5-6.5 inches
- Weight: .75-1 ounce
- Wingspan: about 10 inches
- Conservation status: Least Concern
These sparrows may seem plain and unremarkable at first, but birders who learn to look for subtle field marks can soon recognize what makes them distinct. The slender, conical-shaped bill, long notched tail, and deep belly shape are the first clues to note. 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 cheek 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 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 shoulder patch is visible, but it is not always 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.
These sparrows have a clear musical song that begins with two to four long, slow whistled notes followed by several buzzy trills and warbles. The song can seem almost lyrical in nature and is how the bird earned its name, as these birds sing at twilight, at the same time vespers music may be played. The typical call note is a sharp chirp.
Habitat and Distribution
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 and are quick to reclaim areas that may be abandoned, such as mining facilities or livestock pastures.
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 into South Dakota, Iowa, and 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.
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 are apt to run or walk away from danger rather than take flight immediately.
Diet and Feeding
Like most sparrows, vesper sparrows are generally granivorous, eating a wide range of seeds and grain. They will include small insects in their diet as well, particularly while nesting when young birds need more protein in their diet for proper growth. These birds typically forage on the ground, scratching to loosen choice morsels.
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.
Eggs and Young
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 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 up to three 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.
Vesper Sparrow 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, and protecting that habitat is the key to ensuring the birds' survival and population growth.
Tips for Backyard Birders
Leaving suitable singing perches available can help attract these birds so birders can enjoy their melodies. A ground bird feeder with mixed bird seed, 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.
How to Find This Bird
If birders cannot attract these sparrows to their own yards, they may still be able to see vesper sparrows in appropriate habitats, particularly along rural roadsides and weedy agricultural fields. Check areas where flowers have gone to seed and where dusty areas are abundant, as those two features will attract vesper sparrows easily.
Explore More Species in This Family
The vesper sparrow is only one of the interesting types of sparrows to be found in North America. Birders interesting in learning about similar species should take note of these birds:
BirdLife International. Pooecetes gramineus. The IUCN Red List of Threatened Species 2016: e.T22721188A94703310. doi:10.2305/IUCN.UK.2016-3.RLTS.T22721188A94703310.en