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Vesper Sparrow

A small bird found in grasslands and prairies across North America. It has brownish-gray upperparts with black and rusty-brown streaks, and buffy underparts with a central breast spot. It has a distinctive white eye ring and a white stripe above the eye. It is known for its evening song and feeds mainly on seeds and insects.

An open country sparrow breeding across much of the U.S. and southern Canada, the Vesper Sparrow migrates nocturnally, and often in small groups. Vesper Sparrows are territorial during the breeding season, and territory size is variable. Areas with more food typically result in smaller territory sizes.

Nest parasitism by Brown-headed Cowbirds is common, and has ranged from about 4 percent to over 60 percent in various studies. Vesper Sparrows accept cowbird eggs, and parasitized nests have been shown to have smaller sparrow clutches and reduced production of sparrow young.

 

Description of the Vesper Sparrow

Vesper sparrow

BREEDING MALE

Vesper Sparrow has a grayish back with dark streaks, a white eye ring, and white to creamy underparts with a streaked breast and flanks.  In flight, it shows white outer tail feathers.

Female

Sexes similar.

Seasonal change in appearance

Fall birds are buffier below.

Vesper Sparrow

Juvenile

Juveniles are similar to adults.

Habitat

Vesper Sparrows inhabit meadows, weedy fields, and roadsides.

Diet

Vesper Sparrows eat insects and seeds.

Vesper sparrow

Vesper Sparrow (Pooecetes gramineus) perched on a rock in Alberta, Canada.

Behavior

Vesper Sparrows forage on the ground, often on bare soil.

Range

Vesper Sparrows breed across southern Canada and the northern half of the U.S. They winter across the southern U.S. and Mexico. The population has declined in recent decades.

Fun Facts

Vesper Sparrows can often be identified by their white outer tail feathers when they flush from the roadside ahead of an approaching vehicle.

Vesper Sparrows often associate with other open country sparrows during the winter months.

Vocalizations

The song consists of a series of whistles followed by trills. A  sharp “chip” call is given as well.

Similar Species

Nesting

The Vesper Sparrow’s nest is a cup of grasses and weeds and is lined with finer materials. It is placed on the ground, often near a grass clump.

Number: Usually lay 3-4 eggs.
Color: Whitish or pale greenish with darker markings.

Incubation and fledging:
The young hatch at about 11-13 days, and fledge at about 9-10 days, though remaining dependent on the adults for some time.

Bent Life History of the Vesper Sparrow

Published by the Smithsonian Institution between the 1920s and the 1950s, the Bent life history series of monographs provide an often colorful description of the birds of North America. Arthur Cleveland Bent was the lead author for the series. The Bent series is a great resource and often includes quotes from early American Ornithologists, including Audubon, Townsend, Wilson, Sutton and many others.

Bent Life History for the Vesper Sparrow – the common name and sub-species reflect the nomenclature in use at the time the description was written.

EASTERN VESPER SPARROW
POOECETES GRAMINEUS GRAMINEUS (Gmelin)

Contributed by ANDREW J. BERGERHABITS

Early American ornithologists called this species the bay-winged bunting or the grass finch. According to T. S. Roberts (1932): “It was John Burroughs who gave to this bird the inappropriate name of Vesper Sparrow because he felt that its singing was sweeter and more impressive toward evening, but its simple lay is by no means a vesper song as it may be heard at all hours of the day.” It is true that the clear, far-carrying song of the vesper sparrow is perhaps more conspicuous in the still of warm summer evenings after most of the song sparrows and field sparrows have stopped singing and when the Henslow’s sparrows begin in earnest to give forth With their short and improbable song. But the vesper sparrow sometimes sings just as persistently shortly after dawn on cold April days.

George M. Sutton (MS.) writes: “Singing continues virtually all day long during midsummer, though it is less fervent during the middle of the day in very hot weather; it is especially brilliant on calm evenings or just after a rain. On June 24, 1946, I heard the first song of the morning at 4:05 a.m. (e.s.t.). Thereafter singing was almost continuous until about 11:00 o’clock, at which time it subsided for about two hours. Singing after sunset, even in the gathering dusk, is a common midsummer phenomenon.” The vesper sparrow is, however, better known to many for its white outer tail feathers, which provide an excellent field mark when the bird flies away from the observer, rather than for its song (which some confuse with that of the song sparrow).

Spring: The first vesper sparrows usually arrive in the northern states (Massachusetts, New York, Michigan, Minnesota) during the last week or 10 days of lvlarch, and the spring migration is well under. way by the first week of April. In Ohio, M. B. Trautman (1940) reports that “throughout spring the species principally inhabited the better-drained and more upland fields and pastures. It was found in greatest numbers in sparsely vegetated fields, and in close-cropped pastures and meadows. It never flocked in large numbers in spring, and seldom more than 15 birds were seen in a well-organized flock, and then only early in the season. During the last half of the migration it was always well scattered over fields and pastures. When several birds were flushed they did not group together, but flew a short distance by themselves and dropped independently to earth.” In his report on the birds of Lucas County, Ohio, L. W. Campbell (1940) states that spring flocks of 25 or 30 birds were sometimes seen and that the greatest number seen in one day was 100 (on Mar. 31, 1932). Cordelia J. Stanwood (MS.) writes that at Ellsworth, Maine, the first vesper sparrows were seen in mid-April, or a few days earlier.” Her earliest record was Apr. 6,1909; on Apr. 13, 1916, she saw about 30 birds, the first seen that year.

Territory: Although much remains to be learned about the territorial behavior of the vesper sparrow, we know that this species uses a much larger home range than do certain other sparrows. On a 10-acre field near Ypsilanti, Mich., cultivated in part the previous year and surrounded by woods on three sides, I found 15 pairs of song sparrows, 8 pairs of field sparrows, and only 3 pairs of vesper sparrows, all of which had established nesting territories. At the Edwin S. George Reserve, also in southern Michigan, Francis C. Evans (MS.) studied a 14-acre uncultivated field for 8 years (1949: 56). He found that the number of breeding territories vesper sparrows established during this period “has ranged from a minimum of 8 to a maximum of 12. The entire field seems to be utilized by the birds, and this would give an average territory size ranging from 1.2 acres at the highest population density to 1.8 acres at the lowest density. However, the birds have frequent recourse to the adjacent woods, penetrating at least 50 or 60 yards, and if territory boundaries are extended into the woods, the average territory may be somewhat larger than the estimate just given. We have frequently seen the vesper sparrow in territorial combats essentially similar to those described by M. ~vl. Nice (1937: 57: 58; 1943: 153: 156) for the Song Sparrow.” John L. George (MS.) found 9.9, 8.7, and 9.5 pairs of vesper sparrows per 100 acres of cultivated farm land during a 3-year study in southern Michigan.

It seems likely that the number of pairs inhabiting extensive cultivated tracts planted to hay, wheat, or corn is limited by the number of available song perches rather than by actual territorial conflict. The vesper sparrow rarely sings on the ground, and it seems to prefer the highest singing perches available. Favorite song perches in nesting areas bordered by woods are branches 25 or more feet above ground along the woods’ edge. Where there are no trees, the song perch may be a fence, a dead weed, a thistle, shrub, or any vegetation or structure higher than the nesting substrate.

G. ~V1. Sutton (MS.) notes: “In areas inhabited by both vesper and grasshopper sparrows I have never witnessed interspecific territorial disputes of any sort. I think it quite possible that nest-territories of these two species may occasionally overlap. As for the vesper and lark sparrows, I have never scen one species chasing, or fighting with, the other.”

Rarely I have observed a vesper sparrow chase a song sparrow or a field sparrow, but usually these species nest and feed together without conflict. On May 10, 1946 I found a vesper sparrow nest 14 yards from a killdeer (Oharadrius vocijerus) nest and 21 yards from a field sparrow nest. Ralph A. O’Reilly, Jr., found a nest July 3, 1950 only 10 feet from a killdeer nest.

Courtship: According to E. II. Forbush (1929), “courtship is carried on mostly on the ground. The male walks or runs before or after the female, with wings raised, and both wings and tail widely spread, occasionally rising into the air to give his flight-song.” However, the vesper sparrow rarely gives a true flight song.

Nesting: As far as is known the vesper sparrow invariably places its nest on the ground, frequently near small patches of bare ground or where the vegetation is sparse and low. First nests: those built in April or early May: may be built in an excavation in the ground under cover of prostrate dead weed stems; these nests may be very well concealed by a complete matted covering of such weeds. Nests along dirt roads or country lanes, or those placed in last year’s alfalfa or corn fields, usually are built at the base of a grass tussock, a thistle, a dandelion, some other plant, or even a clod of dirt. Some nests are nearly completely exposed from above during the egg-laying period, but with the rapid growth of spring vegetation, these nests may be well hidden by the time the eggs hatch. John L. George (MS.) found the preferred habitat on farmland to be a “hay field giving a yield of one ton per acre,” hut that “each year several pairs established territories in corn stubble of the previous year, which already had a heavy growth of foxtail, Setaria.”

The vesper sparrow is one of the nesting associates of the Kirtland’s warbler (Dendroii~a kirtlandii), both in plantations of jack pine (Pinu.s bankaiana) and in areas in which natural growths of jack pines are repopulating burned territory. In Minnesota, T. S. Roberts (1932) writes, “Its favorite haunts are the open, dry uplands, wild or cultivated. In the forests of the north every clearing, old burnedover area, wind-fall, or cut-over region, has its considerable quota of vesper sparrows.”

At Buckeye Lake, Ohio, M. B. Trautman (1940) writes: “The species mostly nested in short-grass pastures and meadows, and in better-drained fields of short sparse vegetation that were cultivated or fallow. It appeared to avoid heavy viscous clays and concentrated in lighter soils ~vhich contained considerable sand and gravel. Because of its preference it was found in greatest nesting abundance on the gravelly and well-drained slopes and tops of glacial moraines south and east of the lake.” Trautman adds that “all nests were built in small depressions made in the earth by the bird previous to actual nest building,” and that “the nests of rootlets and fine grasses were in some instances lined sparingly with cattle or horse hair.” E. H. Eaton (1914) also mentions that the nest is “rather loosely constructed of coarse grass and weed stalks, lined with finer grasses, rootlets, and long hair.” T. S. Roberts (1932) says that the nest is in some areas “a depression in the ground lined with grasses, and in the north with pine needles.”

Writing of this species at Ellsworth, Maine, Cordelia J. Stanwood (MS.) says that “in my immediate vicinity, the vesper sparrow nests in a meadow that has been under cultivation or used for pasturage for more than a century, and it breeds in old fields where hay is sparse, fine, and weedy and the ground in many places is covered with sphagnum moss, birdwheat moss, and reindeer lichen; such fields often are grown over in spots with highland cranberries and blueberries.”

Francis H. Allen (MS.) observes that “one who is familiar with the open fields and pastures with short grass ~vhich always seem to be the normal habitat of this species may be surprised to find that it is a common breeding bird in the wide stretches of beachgrass on the seashore, where the Savannah sparrow also breeds.”

The nesting season of the vesper sparrow is a long one, extending from about the third week of April to about the middle of August in Michigan, New York, and Ohio, and probably also in Minnesota.

In southern Michigan, I have found nests with eggs as early as Apr. 21, 1946; Mrs. Alice D. Miller found an adult building a nest on July 14, 1952; George M. Sutton found a nest with three eggs on July 31, 1935: the nest and eggs were destroyed August 6 or 7. Young out of the nest have been found as early as May 11, in 1946 and 1949, and young have been observed to leave nests as late as Aug. 3, 1942 and Aug. 5, 1948. In Ohio, M. B. Trautman reports that “the first young out of the nest were observed May 17 (1930, at least 2 young), and the last August 13 (1925, 1 young).” Cordelia J. Stanwood (MS.) mentions a nest in Maine in which the first egg hatched on Aug. 13, 1909.

T. S. Roberts (1932) gives a good description of the behavior of the vesper sparrow when flushed from its nest: “When it slips from the nest, almost at one’s feet, it frequently feigns injury * * * fluttering along the ground with wide-spread tail and dragging a wing or leg, as though badly crippled. More commonly it flies directly away, low over the ground * * “.” Some female vesper sparrows consistently leave a nest with eggs without feigning injury or giving alarm notes and fly 50 or 60 yards to a tree, but their behavior may change completely after the eggs hatch. Then the bird may run along the ground with tail widely spread, so that the white feathers are conspicuous, and with both wings held over the back and fluttering slightly, much as some song sparrows are prone to do.

Eggs: T he vesper sparrow usually lays from three to five eggs, and sometimes six. They are ovate and have a slight gloss. The ground color is creamy white or pale greenish white, with spots, blotches, scrawls, and cloudings of “sorghum brown,” “Verona brown,” “russet,” or “Mars brown,” and black, with undermarkings of “pale mouse gray.” The eggs of this species show considerable variation in both type and amount of markings. Some have spots, blotches, and scrawls about equally distributed over the entire surface; others may have a few very dark brown or even black scrawls at the large end with only a few fine spots over the rest of the egg. The markings may be all in one shade of brown, or in two or three shades of brown mixed with the “pale mouse gray.” The measurements of 50 eggs of the nominate race average 20.7 by 15.2 millimeters; the eggs showing the four extremes measure p2.9 by 16.3, 21.8 by 16.8, 18.3 by 14.7, and 18.8 by 13.1 millimeters.

While four eggs seem to constitute the usual clutch for spring nests, a few five-egg clutches have been reported (Baillie and Ilarrington, 1937). M. B. Trautman (1940) found five nests with five eggs or young and one nest that held one cowbird egg and six sparrow eggs. Francis C. Evans (MS.) found the number of eggs in 96 complete clutches to be: 2 eggs, 4 sets; 3 eggs, 25 sets; 4 eggs, 67 sets; the mean clutch size was 3.7 eggs. He adds that there is “a distinct seasonal decline in clutch size: most of the clutches produced in May contain 4 eggs, most of those produced in late June and July contain 3.” There are exceptions, however, and I have found July nests with four eggs, both in southern Michigan and in Oscoda County; Douglas S. Middleton found a nest with four eggs on July 12, 1947 (Oakland County, Mich.); G. M. Sutton found a nest at the Edwin S. George Reserve in which three of the four eggs hatched on July 24, 1942; and Lawrence H. Walkinshaw found a nest with five eggs on July 15, 1945. Mr. Bent (MS.) mentioned two nests, each with four eggs, found in Massachusetts on July 1,1886 and July 9,1887.

Young: The incubation period is reported by John L. George (MS.), Francis C. Evans (MS.), and L. H. Walkinshaw (MS.) to vary between 12 and 13 days; some authors have given the period as 11 to 13 days. Incubation is performed chiefly by the female, but E. H. Forbush (1929) comments that both sexes “have been seen on the nest,” and Evans has recorded four instances in which the male was flushed from a nest containing eggs. Both adults have been observed to eat the egg shells. E. M. and W. A. Perry (1918) watched one parent “take a shell some few feet away from the nest before eating it.”

The female usually and the male occasionally brood the young. The amount of time the young are brooded depends in part on the time of the year, that is, they are brooded more in early May than in June and July. During hot summer days the young also are shielded from the sun, usually by the female. Both adults feed the nestlings and both eat or carry away the fecal sacs.

As with many ground nesting passerines, the nestling period varies considerably from nest to nest. John L. George (MS.) found that in two vesper sparrow nests “the young fledged 9 days after hatching; in a third, 10 days; in a fourth, 13 days; and in a fifth, 14 days.” If they are disturbed: by banding, weighing, or by a predator: the young will leave the nest at 7 or 8 days of age. Francis C. Evans found the nestling period to vary from 7 to 12 days, and found the mean period to be 9.1 days. The young are unable to maintain flight when they leave the nest, but they are very quick and agile in moving through the vegetation. Once the young have left the nest, they remain quietly hidden, except when being fed, and they are extremely difficult to find.

The male apparently takes over most of the feeding of the first brood while the female begins a second nest. The fledglings appear to be semi-dependent on the adults until about 30 to 35 days of age. Evans found adults feeding banded young “which had left the nest 18 to 22 days previously.”

Although the long nesting season has led many ornithologists t.o assume that the vesper sparrow is double-brooded (“probably even three sometimes,” Forbush, 1929), two recent investigators, working with color-banded birds, have proved that the vesper sparrow is indeed double-brooded, at least in southern Michigan. John L. George (MS.) reports that “a banded pair that raised two broods successfully hatched the second brood 29 days after the hatching of the first.” Francis C. Evans found one female that successfully raised three broods in one season and states: “Of the remaining 28 records, 13 raised two broods and 15 raised only one brood. I cannot definitely say of any pair that it failed to raise even a single brood, and I believe that almost every pair succeeds in raising at least one brood.”

On May 17, 1946 I observed copulation by a pair of vesper sparrows on the ground in whose nest the first egg (cowbird) had hatched that day; the male then flew to a tree some 50 yards away and the female returned to the nest. That this species undoubtedly is doublebrooded in New York is suggested by E. H. Eaton’s (1914) statement that fresh eggs may be found “from the 28th of April to the 20th of May,” and that “later sets are frequently observed from the 20th of June to the 25th of July.” Theoretically there is time in the period mentioned above for a pair of vesper sparrows to raise four broods during a single season. In view of the frequent destruction of nests, however, such a possibility is unlikely. Evans found 52 percent of 137 nests to be successful in fledging at least one young sparrow.

Plumages: G. M. Sutton (1935) made a careful study of the juvenal plumage of the eastern vesper sparrow, which he describes as follows:

The natal down of this species is grayish brown. With the molting of this down a heavily streaked, strongly black-and-white nestling-stage of the juvenal plumage appears. Individuals from eight to twelve or fifteen days old are in this dark plumage-stage, which appears to be as nearly a complete juvenal plumage as the species ever wears. The scapulars are very dark, the dark areas in the middle of each feather being broad and the margins comparatively narrow. Feathers of the back, neck, and crown also have broad black medial streaks and narrow margins; and the underparts, except for the middle of the belly, are more heavily and more definitely streaked with black than in any subsequent plumage or plumage-stage. The fact that many feathers of the loral, superciliary, mental, and malar regions are still partly sheathed gives the face a strongly black-andwhite appearance that it does not have a few days later.

In a later paper, G. M. Sutton (1941) adds: “Each of my three captive birds began its postjuvenal molt when approximately eighteen days old. * * * As for the time at which the postjuvenal molt begins in the young of first broods, until we have more facts it is unwise to make further assertions. * * * It is quite possible, therefore, that the young of first broods molt more slowly than do the young of second (and third) broods or that, quite independently of age, all young birds of a given summer begin their postjuvenal molt more or less simultaneously.” He found that the postjuvenal molt usually involves “on1y the body plumage,” but that it “occasionally involves the outermost primary, but not the other remiges or the rectrices.”

J. Dwight (1900) comments that the “Sexes are practically alike in all plumages, although the colors will average duller in the female, and the moults are the same.” He adds that the first nuptial plumage is “acquired by wear which is marked and produces a brown-streaked plumage. The bulls and browns are largely lost. A few new feathers may be assumed about the chin in spring, but there is no evidence of a moult.” The adult winter plumage is acquired by a complete postnuptial moult beginning in mid-August. Practically indistinguishable from first winter dress, sometimes paler below, the tertiary edgings rather darker.”

Food: E. H. Forbush (1929) writes that the food of the vesper sparrow “consists of nearly one-third animal matter, chiefly insects, * * * including many first-class pests such as weevils, click beetles, grasshoppers, locusts, cut-worms, army-worms and moths of destructive species.” T. S. Roberts (t932) states that “Among the seeds taken (about one-third the entire food) are ragweed, purslane, wild sunflower, lamb’s quarters, pigeon- and crab-grass, knotweeds, and grain (mostly waste).”

Behavior: Field ornithologists often observe the vesper sparrow’s propensity for taking dust baths. This behavior is well described by G. M. Sutton (MS.) who writes:

“The most distinctive attribute of the vesper sparrow is, perhaps, its liking for dust baths. Young vesper sparrows which I reared in captivity in 1935 and 1940 bathed in dust almost daily (Sutton, 1943: 4), whereas young field sparrows, Henslow’s sparrows, indigo buntings, and cardinals never did. Noncaptive vesper sparrows, both young and adult, take dust baths frequently. A common phenomenon of the Edwin S. George Reserve in midsummer is dust puffing out from the plumage of vesper sparrows surprised into sudden flight along a road; another is vesper sparrow tracks leading up and down the ruts to and from little basins of dust in which the birds have bathed.

“A favorite haunt of the vesper sparrow in midsummer is a flat stretch of road in the very middle of the Reserve. The birds do not flock here: they fly up singly or in twos or threes: but the place is obviously attractive to them. Food is abundant in the form of seeds and insects. The habitat is open, the only trees being widely scattered elms, oaks, and small cedars. Mullein is fairly common. Under the broad leaves of this plant the birds find shade when the sun is very hot. Best of all is the road itself, with its clear-cut, dust-filled ruts, some ofwhich are deep enough to furnish shade. I have never walked along this road in summer without flushing several vesper sparrows. I make this statement advisedly, for I have found the birds there at all hours. Early in the morning I have found them feeding. Later in the morning I have seen young birds at play, chasing each other up and down the ruts or squatting on the bare ground, nibbling at grassblades. At noon on hot days, I have watched both young and old birds seek shady spots. At night I have flushed them between the ruts and returned the following morning to discover little piles of droppings marking the roosting places, as well as the footprints of a fox in the dusty ruts only a few inches away.”

G. M. Sutton comments further that the vesper sparrow “does not, apparently, depend upon a regular water supply either for drinking or for bathing. During the very dry summer of 1936 many species came daily to the spring just south of Colonel George’s house: but neither the vesper sparrow nor the grasshopper sparrow was among them.”

Voice: Aretas A. Saunders sent the following information to Mr. Bent: “The song of the vesper sparrow is sweet and musical. It suggests that of the song sparrow, but has a more definite form. The song in the east rises in pitch and then falls, the notes when the song rises being rather long and slow, but when the pitch falls the notes are shorter and more rapid. The rising notes are commonly in two pairs, the second pair being higher in pitch than the first. The short notes usually begin on the highest pitch of the song and are commonly in groups of three to five notes, each group lower in pitch than the preceding. The paired notes at the beginning are often downward slurs. My records seem to show that birds of central and western New York begin songs with slurs more frequently than those of Connecticut.

“The length of songs varies from 2.4 to 4.2 seconds, the average being 3.25. Pitch varies from B” to D””. The pitch interval varies from two to six tones, the latter being exactly an octave.

“Two records from North Dakota and two from South Dakota seem to indicate a difference in the song. The long notes at the beginning are the highest piteh of the song, and the whole song trend is downward in pitch, not up and then down. This may be the song of the western subspecies (confinis), but the Check-List range is rather indefinite about this.”

Enemies: One is rarely fortunate enough to observe the destruction of a bird’s nest or to account for the disappearance of eggs or young. However, E. M. and W. A. Perry (1918) describe finding a garter snake that had caught a fledgling vesper sparrow. Nicholas L. Cuthbert sent the following eye-witness account of the destruction of a nest:

“At about 4:20 p.m. on July 13, 1956, in a field one mile west of Mount Pleasant, Mich., Frank Gardner and I flushed a vesper sparrow from its nest at the base of a small mullein plant. The bird feigned injury, fluttered along the ground, and disappeared in the vegetation about 20 feet from the nest. After checking the nest, which contained two eggs, we left the area, but returned at 4:50 p.m., again flushing the bird from the nest. Again it fluttered away. We then withdrew to a small weed-covered mound 60 feet from the nest and, while hiding somewhat in the weeds, watched the nest with 8-power binoculars. At 4:52 p.m. we realized that a 13-lined ground squirrel (Citellus tridecemlineatus) had quickly approached the nest and had taken one of the eggs. The ground squirrel sat on its haunches about 4 inches from the nest, holding the egg in its forepaws, and rolled the egg over and over as it ate the contents. After a few minutes, the squirrel dropped the apparently empty shell and took up a crouched position over the nest, as if eating the other egg. At 4:57 p.m. a vesper sparrow appeared and instantly pounced upon the ground squlrrel and pecked it from above as it dashed away into some grass. The sparrow immediately returned to the nest, hesitated a moment to eat the shell, which the ground squirrel had discarded, and then settled on the nest. At 5:03 p.m. the ground squirrel again approached within a foot of the nest and the sparrow left the nest, attacked the squirrel, and drove it into the grass. The sparrow returned, stood by the nest for a moment, then departed. We went to the nest and found it empty; only a small fragment of an egg shell lay on the ground beside the nest.”

F. N. Hamerstrom, Jr., and F. Hamerstrom (1951) report finding the remains of vesper sparrows at nests of the Cooper’s hawk.

Reports in the literature on cowbird parasitism of vesper sparrow nests are conflicting. H. Friedmann (1929) considered the species “a common victim,” but added that there was just one record from Ithaca, N.Y. E. H. Eaton (1914) considered the vesper sparrow among the “commonest” of hosts in New York State. Francis C. Evans found only one out of 85 nests parasitized at the Edwin S. George Reserve in southern Michigan, and G. M. Sutton found no parasitism of 11 June and July nests at the Reserve, although he saw a vesper sparrow feeding a fledgling cowbird, July 25, 1936. In southwestern Michigan, James F. Ponshair found four nests parasitized out of a total of 25 nests; in Ohio, M. B. Trautman found 3 of 14 nests parasitized.

The available evidence suggests that the degree of parasitism of vesper sparrow nests varies both with the nesting habitat and with the time of the breeding season. Because relatively few species are nesting at the start of the cowbird’s laying season, April and early May vesper sparrow nests are more apt to be parasitized than later nests. H. W. Llann (1937), M. M. Nice (1937a), J. Van Tyne (in Bent, 1953), and others have described the cowbird’s habit of watching host species in the process of building nests. A. J. Berger (1951a) states: “I believe that there is a correlation between parasitism and proximity to higher vegetation. In general, parasitized nests in fields were near bordering woodlots or thickets, whereas non-parasitized nests were not near such vegetation. Thickets and trees apparently provide perches and cover for female cowbirds on the alert for nest building activity.”

Banding: John L. George (MS.), writing of his study of the vesper sparrow in southern Michigan, reports that “of eight adults banded in 1948, six (75 percent) returned * * * the following year; and of 16 banded adults present in 1949, 5 (31 percent) returned in 1950.’, One pair remained mated for two years, but none of 45 banded nestlings was seen in subsequent breeding seasons. L. H. Walkinshaw (MS.) studied a male vesper sparrow that returned to the same nesting territory for 4 consecutive years; for the first 2 years this male had the same banded mate.

DISTRIBUTION
Range: Northern Minnesota, central Ontario, southern Quebec and Nova Scotia south to northern Tamaulipas and the Gull coast.

Breeding Range: The eastern vesper sparrow breeds from northern Minnesota (eastern Marshall County), central and northeastern Ontario (Rossport, Moose Factory, Lowbush), southern Quebec (Blue Sea Lake), Prince Edward Island, and northern Nova Scotia south to central Missouri (Appleton City, St. Louis), southern Illinois (Murphysboro, Mount Carmel), central Kentucky (Lexington), northeastern Tennessee (Tate Spring, Johnson City), western and central North Carolina (Weaverville, Greensboro), and south central Virginia (western Amelia County, Richmond).

Winter Range: Winters from central Texas (Ingram, Waco), Arkansas (Rogers), southern Illinois (Murphysboro), central southern Kentucky (Mammoth Cave), West Virginia (French Creek), southeastern Pennsylvania (Edge Hill), central New Jersey (Princeton), and Connecticut (Guilford) south to northeastern Tamaulipas (Matamores), the Gulf coast, and central Florida (Seven Oaks, Micco); occasionally north to Ontario (Point Pelee, Toronto) and Nova Scotia (Wolfville); in migration west to eastern Nebraska, eastern Kansas, and eastern Oklahoma.

Casual records: Casual in Yucatan (Chich~n Itz~i), southern Florida (Key West), and Bermuda.

Migration: The data deal with the species as a whole. Early dates of spring arrival are: Virginia: Richmond, March 10. West Virginia: Licking County, March 4. Maryland: Caroline County, March 1; Laurel, March 5 (median of 7 years, March 22). Pennsylvania: Wilkinsburg, February 26; Somerset County, March 16. New Jersey: Moorestown, March 5. New York: Cayuga and Oneida lake basins, March 11 (median of 21 years, April 2). Connecticut: Hartford, March 12; Bridgeport, March 14. Rhode Island: Pawtucket, March 12. Massachusetts: Martha’s Vineyard, March 18 (median of 5 years, April 11); Concord, March 22. Vermont: Bennington, March 25 (median of 23 years, April 10). New Hampshire: New Hampton, March 27 (median of 21 years, April 13). Maine: Orono and Farmington, April 2. Quebec: Montreal, March 27. New Brunswick: Fredericton, April 8; Scotch Lake, April 9. Nova Scotia: Bridgetown, April 12 (average of 28 years for Nova Scotia, April 22). Prince Edward Island: North River, April 17. Arkansas: Fayetteville, March 14. Tennessee: Nashville, March 1 (median of 15 years, March 22); Knox County, March 6. Kentucky: Eubank, February 23. Missouri: St. Louis, March 8 (median of 13 years, March 21). Illinois: Urbana, March 5 (median of 19 years, March 28); Chicago, April 1 (average of 14 years, April 7). Indiana: Wayne County, March 15 (median of 18 years, March 27). Ohio: Canton and Hilsboro, March 5; Buckeye Lake, March 8 (median of 40 years for central Ohio, March 25). Michigan: Detroit area, March 16; Battle Creek, March 22 (median of 40 years, April 1). Ontario: London, March 22; Ottawa, April 1 (average of 17 years, April 13). Iowa: Sioux City, April 8 (median of 38 years, April 25). Wisconsin: Dane County, March 19. Minnesota: McLeod County, March 23; St. Paul, March 31 (average of 18 years for southern Minnesota, April 5). Texas: Valley, March 30. Oklahoma: Cleveland County, March 14. Kansas: northeastern Kansas, March 21 (median of 17 years, March 31). Nebraska: Red Cloud, March 14. South Dakota: Rapid City, March 9. North Dakota: Jamestown, April 19. Manitoba: Margaret, March 30; Treesbank, April 12 (average of 25 years, April 18). Saskatchewan: Conquest, April 2. Mackenzie-Fort Simpson, April 24. New Mexico-Mesilla Park, March 2. Arizona: Flagstaff, February 28; Camp Grant, March 1. Colorado-Boulder, April 2. Utah: Kanab, March 5; Washington County, March 8. Wyoming: Yellowstone Park, March 31. Idaho: Lewiston, March 24 (median of 11 years, April 10). Montana: Billings, April 4; Moiese, April 14. Alberta: Buffalo Lake, April 12. California: Inyo County, April 4. Nevada: Mercury, March 13; Carson City, April 2. Oregon: Kiamath County, March 23. Washington: Yakima, March 14; Grant County, April 10. British Columbia: Okanagan Landing, April 4.

Late dates of spring departure are: Florida: Tallahassee, April 22; Old Town, April 15. Alabama: Birmingham, April 20; Jackson, April 15. Georgia: Atlanta, May 5. South Carolina: Charleston, May 11; Clemson College, April 23. North Carolina: Raleigh, May 11. Virginia: Richmond, April 24. District of Columbia: April 15. Maryland: Baltimore County, May 23; Worcester County, May 16. Louisiana: Baton Rouge, March 26. Mississippi: Gullport, March 31. Arkansas: Fayetteville, April 10. Tennessee : Knox County, May 7. Kentucky: Eubank and Bowling Green, May 6. Missouri: St. Louis, April 15 (median of 13 years, April 2). Illinois: Chicago, May 3 (average of 14 years, April 28). Texas: Sinton, May 7 (median of 5 years, April 30). Oklahoma: Cleveland County, April 28. California: Parker Dam, May 20.

Early dates of fall arrival are: California: Fresno, September 12. Oklahoma: Payne County, September 27. Texas: Sinton, September 17. Illinois: Chicago, September 18 (average of 13 years, September 30). Missouri: St. Louis, September 11 (median of 13 years, October 2). Kentucky: Bardstown, September 12. Tennessee: Nashville, October 5; Knox County, October 9. Mississippi-Saucier, October 27. Louisiana: Baton Rouge, November 18. New Jersey: Island Beach, October 7; Cape May, October 12. Maryland: Talbot County, September 2; Prince Georges County, September 9. District of Columbia-September 1. Virginia: Richmond, October 10. North Carolina: Raleigh, October 11. South Carolina: Charleston, September 22 (median of 6 years, October 12); Sunimerton, September 24. Georgia: Fitzgerald, October 1. .Aiabama: Camden, October 13; Booth, October 17. Florida: DeFuniak Springs, October 5; Tallahassee, October 13.

Late dates of fall departure are: British Columbia: Okanagan Landing, October 16. Washington: Grant County, November 10; Yakiina, November 8. Oregon: Yamhill County, October 9. Alberta: Calgary, October 11. Montana: Big Sandy, October 30. Idaho: Moscow, September 27 (median of 11 years, September 13). Wyoming: Yellowstone Park, October 23. Utah: Spectacle Lake, October 25. Colorado: Fort Morgan, November 25. Arizona: Springerville, November 12. New Mexico: Las Cruces, November 28. Saskatchewan: Eastend, October 29. Manitoba: Killarney, November 9; Treesbank, October 15 (average of 23 years, October 10). North Dakota: Jamestown, November 2. South Dakota: Mettette, November 20. Nebraska: Lincoln County, November 14. Kansas: northeastern Kansas, November 22 (median of 14 years, October 15). Oklahoma: Oklahoma City, November 12. Minnesota: Minneapolis: St. Paul, October 14 (average of 9 years, October 4). Wisconsin: Rock County, November 11. Iowa: Sioux City, November S (median of 38 years, October 15). Ontario: Reaboro and Toronto, October 21; Ottawa, October 17 (average of 17 years, October 7). Michigan: Battle Creek, November 8 (median of 21 years, October 4). Ohio: Buckeye Lake, November 30 (median, October 29). Indiana: Wayne County, October 27 (median of 7 years, October 16). Illinois: Chicago, November 21 (average of 13 years, October 28). Missouri: St. Louis, November 30 (median of 13 years, November 10). Kentucky: : Bardstown, November 18. Tennessee: Nashville and Knox County, November 11. Arkansas: Saline County, November 10. Prince Edward Island: North River, October 7. Nova Scotia: Yarmouth, October 25. New Brunswick: Scotch Lake, November 27. Quebec: Montreal, October 17. Maine: South Portland, November 15. New Hampshire: Concord, October 24; New Hampton, November 19 (median of 21 years, October 20). Vermont: Clarendon, November 2. Massachusetts: Martha’s Vineyard, December 6; Concord, November 28. Rhode Island: Block Island, October 27. Connecticut: New Britain, November 14. New York: Cayuga and Oneida lake basins, December 10 (median of 19 years, November 5); New York City, November 20. Pennsylvania: Pittsburgh, November 21; State College and Renovo, November 17. Maryland: Prince Georges County, November 16. District of Columbia: November 21. West Virginia: Bluefleld, November 16. Virginia: Richmond, November 9. Egg dates: Alberta: 9 records, May 20 to June 7. British Columbia: 22 records, May 20 to July 11; 11 records, June 2 to June 21. California: 15 records, April 28 to July 8; 9 records, May 22 to June 9. Illinois: 35 records, May 7 to July 14; 20 records, May 13 to May 28. Maryland: 31 records, May 5 to August 1; 16 records, May 26 to July 5. Michigan: 51 records, April 21 to July 31; 16+ records, June 15 to June 27. New Brunswick: June 3 to August 15 (number of records not stated). New York: 16 records, April 30 to July 9; 10 records, May 2 to May 26. Nova Scotia: 4 records, May 19 to July 6. Ontario: 63 records, April 23 to July 30; 32 records, May 16 to June 11.

Oregon: 34 records, May 6 to July 18; 18 records, May 24 to June 14.

Quebec: 9 records, May 2 to July 11.

Wyoming: 14 records, May 30 to July 4.

WESTERN VESPER SPARROW
POOECETES GRAMINEUS CONFINIS Baird
Contributed by JAMES R. KING

HABITS

The adults of this race of the vesper sparrow are characterized as slightly larger than those of the nominate race, with a more slender bill, and paler, grayer coloration. The streaks on the breast are not so distinct or dark as in P. graminens. The comparative coloration of the juvenal plumages in P. gramineus sp. is analyzed in detail by R. H. Graber (1955). The principal differences are encountered in the back and crown: confinis: feathers of the back black, broadly edged with buffy white, crown and back streaked with light brown or buff and black, tertials edged rusty and tipped white; gramineus: sirnilar to confinis but dorsum much darker (no white), crown and back streaked with brown (not buff or light brown) and black, tertials edged with brown, not buff.

The ecology and life history of the vesper sparrows of the West have been studied very infrequently, and the published reports yield only a fragmentary picture. During the breeding season P. g. confinis is found in open habitats east of the Sierra Nevada: Cascade mountains system from southern Mackenzie south to eastern California, northern Arizona, and northern New Mexico. The breeding range extends eastward to central western Ontario, western Nebraska, and presumably the Dakotas. The western vesper sparrow occupies an extensive altitudinal range within this area, and is typically absent only from the lower dry areas corresponding to the traditional descriptions of the Lower Sonoran Zone and arid Upper Sonoran Zone. This is demonstrated especially well in eastern Washington, where the race is distributed throughout suitable open grassland and sagebrush areas except for the arid (annual rainfall less than 10 inches) artemisia: agropyron association of the south central Columbia Basin (Daubenmire, 1942; Dumas, 1950; Jewett et al., 1953).

In eastern California J. Grinnell and A. H. Miller (1944) describe the preferred habitat as “artemisia association in which the sagebrush is well spaced * * * or of no more than moderate height. Much open or sparsely grass-covered ground is required, and this usually is level or gently sloping.” In Utah, W. H. Behle (1958) and W. H. Behie, J. B. Bushman, and C. M. Greenhalgh (1958) also emphasize the artemisia association as a major habitat of the western vesper sparrow, but note also that the race occuis in the pinon-juniper association and in the low grass of alpine and subalpine meadows. For the southern Rocky Mountains, F. Lvi. Bailey (1904, 1928) reports breeding populations commonly in meadows as high as 9,000 feet, and occasionally as high as 12,000 feet. S. G. Jewett et al. (1953) mention breeding populations at 5,000 feet in the Blue Mountains of eastern Washington.

The wintering grounds of the western vesper sparrow extend from southeastern California, southern Arizona, New Mexico, and Texas, south through Baja California and west central Mexico to Oaxaca (casually east to Vera Cruz, Louisiana, and Mississippi). The migration between wintering and breeding grounds is very sparsely documented. N. Criddle (1921) reports the mean date of arriv~il of vesper sparrows at Aweme, Manitoba (lat. 49042’N.) as April 18, based on 25 years’ observation; the earliest recorded arrival date is April 12. Records for migrants and summer residents in eastern Washington (Jewett et al., 1953; Hudson and Yocom, 1954) extend from March 10 to September 19. W. B. Davis (1935) reports autumn migrants on November 4 at Rupert, Idaho, but this is exceptionally late. Migrating western vesper sparrows may be observed as far east as western Kansas.

Nests with fresh eggs have been found from April 5 to June 3 in eastern Washington (J. H. Bowles, 1921) and from May 24 to June 20 m eastern Oregon (Gabrielson and Jewett, 1940). In New Mexico (Santa Fe County; Jensen, 1923) fresh eggs have been reported from May 15 to July 15. W. Weydemeyer (1936) mentions two “unusually late” clutches hatched in Montana on July 19 and 25. Other fresh egg dates from Idaho (Davis, 1935) and Utah (Behle, 1958) fall within the above spans. In certain parts of the breeding range, at least, two annual broods are reared. R. B. Rockwell and A. Wetmore (1914) mention a first brood in May and a second one in July near Golden, Colorado.

The nest of P. g. confinis (and P. g. affinis) is described by B. R. Headstrom (1951) as “rather bulky, thick-rimmed, well-cupped but not tightly woven; of dried grass, rootlets, and hair.” Mean dimensions: outer diameter, 4.5 inches; outer height, 1.8 inches; inner diameter, 2.2 inches; inner depth, 1.4 inches. F. M. Bailey (1928) describes the eggs as greenish or brownish white, and often blotched and streaked with reddish brown and lavender. She mentions clutches of four to six eggs in New Mexico. J. K. Jensen (1923), also reporting from New Mexico, cites only clutches of three to four eggs. R. Hoffmann (1927) and E. Stevenson (1942), probably referring also toP. g. affinis, describe the eggs as white, speckled and clouded with reddish brown, and report clutches of four to five eggs.

The measurements of 40 eggs average 20.9 by 15.2 millimeters; the eggs showing the four extremes measure 22.4 by 15.8, 21.8 by 16.8, 18.8 by 14.7, and 19.3 by 14.2 millimeters.

The food habits of the western vesper sparrow in relation to agriculture were studied by G. F. Knowlton (1937a,b) and by G. F. Kno~vlton and W. P. Nye (1948). The insects recognized in stomach analyses were principally injurious forms; the vesper sparrow is cited particularly as a significant predator on the beet leafhopper, E’u,tettiz tenellus (Baker).

DISTRIBUTION
Range: British Columbia, the prairie provinces, and western Ontario south, east of the Casc.ades and Sierra Nevada to southern Mexico.

Breeding Range: The western vesper sparrow breeds from central and northeastern British Columbia (Fran~ois Lake, Pouce Coupe), southwestern Mackenzie (below Norman, Fort Smith), central Saskatchewan (Dorintosh, Prince Albert), central Manitoba (The Pas, Lake St. Martin, Hillside Beach), and central western Ontario (Wabigoon, Rainy River) south, east of the Cascade Range and the Sierra Nevada, to central eastern California (eastern Tulare County, lnyo Mountains), central Nevada (Toiyabe Mountains), southwestern Utah, central northern and central eastern Arizona (Williams, White Mountains), central western and central northern New Mexico (Zuni Mountains, Santa Fe), eastern Colorado, and western Nebraska; casually north in summer to northwestern Ontario (Favourable Lake).

Winter range: Winters from central California (Fresno, Owens Valley), southern Nevada (St. Thomas), central and southeastern Arizona (Camp Verde, San Carlos), southern New Mexico (Fort Webster, Carlsbad), and southern Texas south to southern Baja California (La Paz), Guerrero (Chilpancingo), and Oaxaca (Tamazulapam), casually east to Veracruz (Zacualpilla), Louisiana (Natchitoches), and Mississippi (Saucier); in migration to western Kansas.

OREGON VESPER SPARROW
POOECETES GRAMINEUS AFFINIS Miller
Contributed by JAMES R. KING

HABITS

G. S. Miller, Jr. (1888). describes the adults of this Pacific coastal form of the vesper sparrow as “similar to P. g. confinis with respect to slender bill and narrow dark dorsal streakings, but dillering in being smaller and having the ground color above buffy brown rather than grayish brown. All the lighter areas of the plumage * * * suffused with pinkish buff.” In the juvenal plumage, according to R. R. Graber (1955), P. g. affinis closely resembles P.g. gramineus, but with the black back feathers “only narrowly margined with whitish.” The superciliary line is more distinct and complete than in P. g. conjlnis.

The breeding range of P. g. aftinis is restricted to the lower valleys and plains west of the Cascade Range in Washington and Oregon. I. N. Gabrielson and S. G. Jewett (1940) report it to be an abundant summer resident in the Willamette Valley of Oregon, but less common in other coastal valleys. It is an inhabitant of “open meadow and farm lands where it frequents the fence rows and pasture lands” (Gabrielson and Jewett, 1940), and of “cultivated land and open pastures” (Jewett et al., 1953). in western Washington, summer residents and migrants have been reported from April 4 to September 8 (Jewett et aL, 1953). J. H. Bowles (1921) reports nests with fresh eggs in Washington from May 9 to June 2. Plural broods are not reported for P. g. ajJini8.

The measurements of 40 eggs average 20.7 by 15.2 millimeters; the eggs showing the four extremes measure ~2.9 by 16.3, 21.8 by 16.8, 19.3 by 14.7, and 20.3 by 14.93 millimeters.

The wintering range of the Oregon vesper sparrow lies west of the Sierra Nevada from central California south to northwestern Baj a California, where it overlaps the winter range of P. g. confinis. Migrants are found occasionally as far east as western Utah (Beble and Selander, 1952). The winter habitat in California is described by J. Grinnell and A. H. Miller (1944) as “Open ground with little vegetation or else areas grown to short grass and low annuals. Bushes and taller grass may be used as retreats or for shelter. Often seen in stubble fields and meadows and along road edges where they forage m a skulking manner.” These authors report that the winter residency extends from October to early April; migrants are seen in April and in late August and early October.

DISTRIBUTION
Range: Western Washington to northwestern Baj a California.

Breeding Range: The Oregon vesper sparrow breeds in western Washington (Dungeness, San Juan Islands) and western Oregon (Willamette Valley, Coos Bay).

Winter range: Winters from central California west of the Sierra Nevada (Fulton, Lagrange) south to northwestern Baja California (Santo Domingo).

Casual records: Casual east to southern Utah (St. George, Henry Mountains).

About the Author

Sam Crowe

Sam is the founder of Birdzilla.com. He has been birding for over 30 years and has a world list of over 2000 species. He has served as treasurer of the Texas Ornithological Society, Sanctuary Chair of Dallas Audubon, Editor of the Cornell Lab of Ornithology's "All About Birds" web site and as a contributing editor for Birding Business magazine. Many of his photographs and videos can be found on the site.

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