Contributed by William DeMott Stull
[Published in 1968: Smithsonian Institution United States National Museum Bulletin 237 (Part 2): 1166-1184]
The specific name Alexander Wilson gave this little sparrow, socialis, aptly describes the close relationship many later authors have noted between its habitations and those of man. None has expressed it better than Forbush (1929), who wrote "The Chipping Sparrow is the little brown-capped pensioner of the dooryard and lawn, that comes about farmhouse doors to glean crumbs shaken from the tablecloth by thrifty housewives. It is the most domestic of all the sparrows. It approaches the dwellings of man with quiet confidence and frequently builds its nest and rears its young in the clustering vines of porch or veranda under the noses of the human tenants."
The early writers spoke of it as the most common bird in their areas. Audubon (1841) wrote "Few birds are more common throughout the United States than this gentle and harmless little bunting." But soon after the turn of the century a sharp decline in numbers was noted in formerly populous areas (R. F. Miller, 1933; H. F. Price, 1935; L. Griscom, 1949). The explanations given usually include cowbird predation or competition from English sparrows. Yet in 1954 - 58 the chipping sparrow was the most abundant nesting bird on the campus of the Lake Itasca Forestry and Biological Station in Hubbard County, Minn., in an area where there were many cowbirds and no English sparrows.
While we continue to think of this bird as preferring man's dooryards, lawns, and orchards, we wonder where it existed under primeval conditions. In Itasca State Park, Minn., it occurs in small numbers in stands of jack pine, in virgin black spruce bogs, and in stands of virgin red pine. In the more favored developed areas it lives in abundance. Forbush (1929) says that, "Here and there in the wilder parts of New England Chipping Sparrows may be found in forest openings or along the shores of lakes and streams." On Lake Mistassini, Quebec, Godfrey (1949a) found it confined to a narrow clearing which was "densely populated in summer by noisy Indians and their dogs and enclosing the trading posts of the Hudson's Bay Company and the free trader." The same writer (Godfrey, 1950) found it a "common summer resident in aspen and coniferous forest edges and tall shrubbery on the margins of roads, streams and lakes" throughout the Flotten Lake Region of Saskatchewan, and Rand (1946) found it fairly common along Canol Road in the dwarf-birch and spruce flats bordering a river as well as in muskeg type forest and in open mixed forest. In western Montana Saunders (1914a) records it as a common summer resident in the cottonwood groves in the prairies.
Burleigh (1958) suggests that in Georgia the open pine woods were probably its original habitat, for it is still plentiful in this type of woodland that once covered much of the state and is somewhat similar to the aforementioned stands of jack pine and mature red pine in Itasca Park, Minn.
The evidence indicates that, from one end of its range to the other, the chipping sparrow probably originally inhabited open woodlands or the borders of forest openings produced by rivers and lakes. When man appeared on the scene and began to make clearings for his villages, he created additional open areas which the birds quickly occupied. The axes of the European settlers made a hundred clearings where the aborigines had one, and undoubtedly the chipping sparrow population of today is many times that in pre-Columbian North America. ***
Spring.--The wintering population begins to migrate from the southern costal plain in late winter, and the last stragglers have usually left the coastal regions of Georgia by the middle of April. Farther inland in the uplands of the middle coastal plain, they are usually gone by May 1. In the south the males are singing on their territories by late March. Trautman (1940) has the following to say of their arrival in central Ohio:
It was sometime between March 17 and April 2, usually the last week of March, that the first Eastern Chipping Sparrows arrived. A few days after April 1 a small wave appeared, and by April 10 the species had become numerous. The peak of migration began about April 12 and continued until April 30. Usually, all transients had disappeared by May 5. During the largest flights 5 to 35 could be daily encountered. The earlier arrivals were in groups of 3 to 6 individuals of their own kind, or in flocks of Eastern Field and Allegheny Song sparrows. They could be found about weed patches, weedy and vine-entangled fence rows, and brushy thickets near woodlands. After mid-April individuals and pairs were most frequently observed on lawns, in trees, in shrubbery, and in fields, and about farmhouses, cottages, and villages. In the spring the species preferred uplands and well-drained situations.
The average date Walkinshaw (1944b) reports for first arrivals in southern Michigan is April 13. Roberts (1936) gives April 5 as an average arrival date in southern Minnesota. In central Saskatchewan, over a 4-year period, the average for first arrivals fell in the 2nd week in May (Houston 1953, 1954, 1955, 1956). Usually within 2 weeks after the first arrivals the males are on their territories.
When first observed each spring male Chipping Sparrows have been already attached to certain territories, which they proclaim by singing from some perch during most of the daylight hours. In Battle Creek they were not always completely surrounded by other Chipping Sparrows, so that their territories, although limited on one or more sides, were quite flexible on the others. Territorial defense consisted chiefly in chasing intruders, which then usually left at once. I have often observed a trespasser depart on the mere approach of the resident male with wings slightly lowered and feathers slightly raised. . . . On one occasion a resident male drove away a trespassing female.
Louise de Kiriline Lawrence has submitted the following notes on an encounter she observed between an invading male and a pair that had just fledged its first nestlings: "A chase, then halt on twigs with the strange male singing loudly and vigorously several songs. Chase again, then halt on twigs followed by impudent singing by the strange male and the home male silent. This has gone on for several hours (it went on from 1 p.m. until night-fall) with only short intervals for feedings. Both birds were panting from the heat and exertion. . . . Sometimes the female takes part in the chasing." Mrs. Lawrence adds that the next day the strange male had retired from the scene and the pair was busy building the second nest.
My own observations made in Itasca State Park, Minn., indicate that the female defends at least the area of the nest tree. Two instances occurred while I was trying to trap the parent birds for banding, using the nestlings to lure the parents into the trap. In the first instance I had placed the male in a cage to keep him out of the trap and thrown a jacket over the cage. A neighboring unmated male soon entered the territory and sang. As it approached the nest tree, it stopped and sang at intervals. The female was at the nest and paid no attention until he entered the tree adjacent to the nest tree. She then attacked and he retreated to his own territory. On the second occasion, with a different pair, I released the male from the trap. He flew directly to the nest where again the female was at the empty nest. She immediately drove him out. He soon returned, giving the twitter the male usually uses when approaching the incubating female, and she showed no aggressiveness toward him.
Territories are about an acre in extent. Walkinshaw found them to be between 1 and 1 1/2 acres at Battle Creek, Mich. In 1953 at the Lake Itasca Forestry and Biological Station, 21 pairs nested on 52 acres, but much of this area was unoccupied and some territories were about one-half acre. At the Edwin S. George Reserve in southeastern Michigan, Sutton (1960) concluded that one territory was 70 yards by 45 yards, or approximately two-thirds acre.
Courtship and Mating.--Bradley (1940) reports that in the pair she observed at Douglas Lake, Mich., courtship took place while the female was nest building. "It consisted of outbursts of song by the male from the top of a cabin, interspersed with quick flights to the ground where the female was pulling up weed stalks for the nest. Copulation took place on the ground soon after this display." Walkinshaw (1944b) observes that copulation "which usually took place on the ground, but sometimes on a horizontal branch, wire, or roof, is frequent during the days preceding egg laying and often occurs several times in succession. The female assumes a crouching posture with head and tail slightly raised and wings rapidly vibrating; the male approaches and hovers over her for a few seconds. During copulation the female (and perhaps the male) utters a rapid call, see-see-see-see-see."
Nesting.--The female does all the gathering of nesting material. All observers agree that the female does all the nest building and while the male often accompanies her on her trips to gather nesting material, he usually does not return to the nest tree with her. Nest building goes on throughout the day with greatest activity before noon. Walkinshaw (1944b) states that "most of the nest building was done in the early morning hours," In the single case I observed, nest building was greater during mid-morning than during the first 1/2 hour of the day. The greatest frequency of trips was 11 in 30 minutes. Walkinshaw (1944b) found that nests in May were completed in 3 to 4 days, while the one July nest observed was completed in 2 days. A single observation of what was probably a second nesting in Minnesota in the 2nd week of June indicated that the nest was built in 2 days.
The nest is almost invariably constructed of dead grass, weed stalks, and rootlets and lined with fine grasses and hair. Horsehair seems by all odds the favorite nest lining material and when available is always the principal component of the lining. When horsehair is not available, the birds will use human hair or that of cattle, deer, raccoon, or other animals. In one case, a nest adjacent to a pen of bison was lined with bison hair. Itasca State Park, Minn., is so remote from horses that no nests found in 1954 contained horsehair. In the summer of 1955 a friend generously gave me some black hair from the mane of his horse to take to Minnesota to use as a lure to trap the females for banding. It worked very well. At nest lining time the females readily entered traps containing a few strands of horsehair. Even after I stopped trapping most newly built nests continued to contain the horsehair, for these sparrows commonly remove the lining from old nests when rebuilding.
The size of eight nests Walkinshaw (1952) studied varied between 80 and 150 millimeters (average 112 millimeters) in outside diameter at the top, between 40 and 60 millimeters (average 48.3 millimeters) interior diameter at the top, between 45 and 75 millimeters (average 56.8 millimeters) exterior depth, between 30 and 50 millimeters (average 37.3 millimeters) interior depth, and between 3 and 5.8 grams (average 4.7 grams) weight.
Chipping sparrows nest in a variety of situations and of trees and shrubs. The favored nesting site seems to be in conifers--pines in the Southeast, junipers where they are common, and spruces in the North. Orchard trees and vines are also high on the list of preferences. Of 115 active and inactive nests located in 1954 and 1955 in and around Itasca State Park, 85 were in spruce, 11 in jack pine, 6 in fir, 6 in juniper, 4 in white pine, 1 in red pine, 1 in low willow, and 1 in an Ampelopsis vine. Walkinshaw (1944b) lists 51 nests found near dwellings at Battle Creek, Mich.; of these 14 were in spruce, 8 in arborvitae, 5 in juniper, 8 in grape vines, 7 in the horizontal branches of horse chestnut, pear, or apple trees, 5 in rose or spirea bushes, 2 in the side of old straw stacks, 1 on a mowing machine in a semi-open tool shed, and 1 on the ground in dead grass. Burleigh (1958) states that "Pairs frequenting the open pine woods almost invariably build their nests at the outer end of a limb of one of the larger pines, the height varying from ten to, not infrequently, thirty or forty feet from the ground."
A number of observers in addition to Walkinshaw have reported nests built on the ground. Other unusual nesting sites reported were at the bottom of a hairy woodpecker's winter roost hole 6 inches deep (R. F. Miller, 1923), in a hanging basket filled with moss on a stoop within a foot of the door (F. O. H., 1884) and for 3 years in a row a chipping sparrow nested in pepper plants hung to dry in late summer not far inside a shed on a Philadelphia County, Pa., farm (R. F. Miller, 1911).
Most nests are built at low to moderate heights. At Lake Itasca, of 83 nests measured from May 17 to July 23, 1955, 51 (61.5 percent) were lower than 6 feet and 11 (13.3 percent) were higher than 11 feet. Eighteen of these nests were found between May 17 and June 8 by following individual birds until they flew to their nests instead of searching in what might be considered the most likely places. Of the 18, eight were higher than 10 feet, three were between 19 3/4 feet and 25 1/2 feet and five were between 30 and 36 feet. Of these last five, three were within 8 feet of the top of 35' and 40-foot spruces and firs. In the summer of 1956 Robert Galati found two chipping sparrow nests near the tops of black spruce trees in a mature black spruce bog in Itasca State Park--one was 56.5 feet from the ground in a 58.5-foot tree, the other at 54.5 feet in a 56-foot spruce. They were 70 feet apart and were both being built on July 2 when Galati first observed them. He later witnessed a territorial dispute that began 30 feet up in a dead black spruce and ended with the combatants rolling on the ground. Maurice Broun reports two high nests at Hawk Mountain Sanctuary, Pa., one 30 feet up in the top of a maple overgrown with grape vines, and a second 50 feet from the ground in the top of an oak.
Walkinshaw (1944b) found that the average nesting height became progressively higher during the summer; 15 May nests averaged 3.6 feet from the ground, five June nests averaged 5.0 feet, and seven July nests averaged 7.5 feet.
Eggs.--The chipping sparrow usually lays four eggs, but sometimes only three or as many as five. They are slightly glossy, and ovate with some tending to short ovate. The ground is "bluish glaucous" or "Etain blue," with speckles, spots, blotches, and a few scrawls of dark brown such as "auburn," "Brussels brown," "Argus brown," "mummy brown," or "snuff brown," and black, with undermarkings of "pale neutral gray." They are rather sparingly marked, and most of the spots are confined to the large end where they frequently form a loose wreath. This wreath may be of very small spots or quite long interlacing scrawls. In most instances the spots are rather sharply defined and in many cases the undermarkings are absent. Occasionally an egg will be unmarked. A set of three eggs in the American Museum of Natural History is pure white and unspotted. The measurements of 90 eggs average 17.6 by 12.9 millimeters; the eggs showing the four extremes measure 20.3 by 12.7, 16.8 by 15.2, 15.2 by 12.5, and 16.8 by 11.2 millimeters.
The first egg is laid on the morning following completion of
the nest. One egg is laid each morning usually before 7:00 a.m.,
through sometimes later (Walkinshaw, 1952) until the clutch is
complete. In most cases four eggs complete the set; three-egg sets
are common, and clutches of two and five are rare. Street (1954)
reports on 63 clutches in the vicinity of La Anna in the Pocono
Mountains of northeastern Pennsylvania and Walkinshaw (1944b)
reports on 45 complete clutches in southern Michigan as:
Clutch Size 2 3 4 5 Average
No. of sets (Street) - 17 42 4 3.79
No. of sets (Walkinshaw) 1 15 29 - 3.63
Walkinshaw found that the average clutch size decreased from 3.81 in May to 3.00 in July.
Sets containing five eggs have been reported from Newton, Mass. (G. M. Allen, 1892), Buckeye Lake, Ohio (Trautman, 1940), St. Louis County, Minn. (Roberts, 1936), and Flotten Lake, Saskatchewan (Robert P. Allen, fide Godfrey, 1950). Some variation in egg color and marking has been found. Over a 5-year period Walkinshaw (1952) examined 35 eggs from the same female and found them all darker blue than the usual chipping sparrow eggs, and the markings, usually sparse scrawls, were heavy black. A clutch of unspotted eggs has been reported (Oologist, 1884:70).
Walkinshaw (1952) determined the incubation period for nine nests and found a relationship between the air temperature and the length of the incubation period. The four nests that were incubated during the period of highest average mean temperature (60.2>o to 76.0o F.) had 11-day incubation periods, while when the average mean temperature was lowest (48.7o) the incubation period was 14 days.
As with many song birds, the male feeds the female while she incubates. As he approaches the nest tree he utters a series of low chips, sometimes rapidly. At the sound the female becomes alert and restless, and sometimes leaves the nest to feed near by. At other times she remains on the nest. In one case the male came to the nest and fed the female only 3 minutes after she returned to the nest from being with him. She often chips rapidly, flutters her wings, and begs as he arrives.
The incubating female often can be approached quite closely, which I found most convenient. I marked a number of females on the nest for identification by applying model airplane dope to them with the tip of a stalk of timothy grass.
Young.--When the eggs hatch the female eats the shell (Walkinshaw, 1944b). The young, which are capable of only one activity, feeble gaping, are fed almost immediately. Walkinshaw (1944b) watched the female feed one young 20 minutes and another 28 minutes after hatching. I have observed two first feedings. In one case the male brought food to the nest, the female flew off, and he fed the hatchlings. In the second instance the male brought food and gave it to the female on the nest; she then hopped up on the rim and, while the male stood by, fed the newly hatched young. In nests that I have observed the male did most of the feeding for the first few days, and the female brooded the young. Toward the end of the 3rd day she brooded less and fed the young more often, until, by the last days before the young fledged, she brought food as often as the male. The rate of feeding ranged from 2 trips per hour the first day to 17 per hour toward the end of the nesting period. Some individual differences occur in the roles of male and female in the early feeding. In a nest observed by Bradley (1940) the pattern was the same as in those I watched, but Walkinshaw (1944b) reports a nest where the female did nearly all the early feeding. This was an August nest when the pattern may be somewhat different, especially when the male is still tending young from a previous nesting.
The female does most of the brooding. Walkinshaw (1944b) found that "on a cool morning the male occasionally brooded for a very few minutes." On the first day the young are brooded about 90 percent of the time. This declines until after the 4th day there is little brooding, except when the sun is directly on the nest, at which time the female often stands over the young.
Weed (1898) recorded the activity at a nest containing three young that fledged 2 days later. The observations were made on June 22 and extended from 4:06 a.m., when the brooding parent first left the nest, until 7:50 p.m., when a parent settled down for the next night of brooding. During this period of nearly 15 3/4 hours the parents fed the young 189 times. During the first hour they were fed 13 times. The lowest number of feedings was between 6:00 and 7:00 a.m. when there were 7 trips; the highest was 21 trips between 1:00 and 2:00 p.m. During the last hour of the day the rate was the same as for the first, 13 times.
William R. Dawson and Francis C. Evans (1957) conducted a study on the growth and development of nestling field and chipping sparrows. At hatching the muscular system is poorly developed and the nestlings remain inactive except for gaping for food. The muscular system develops rapidly and by the 4th day they can hold up their heads and are attempting to stand. The capacity for temperature regulation begins to appear on the 5th day and it is quite effective by the 6th. On the 7th the birds are "essentially homeothermic." Dawson and Evans report that on the 6th day they were so active they had to be confined to boxes to prevent escape. I found that in northern Minnesota the 6th day is the best time to band nestlings, for at that age they are large enough to band and may still be easily returned to the nest; 7-day-old nestlings often abandoned the nest after being handled. Dawson and Evans (1957) report that "touching or jarring the nest generally produced a gaping response in 5-day-old or younger individuals whereas such a stimulus caused older birds to crouch low and huddle in the nest." In nests they studied 2 individual nestlings fledged at 8 days, 18 at 9 days, 20 at 10 days, 10 at 11 days, and 2 at 12 days for an average age at fledging of 9.85 days. The nestlings increased from a mean weight of 1.7 grams at hatching to about 10 grams at fledging. Walkinshaw (1944b) found several nestlings still wet from hatching to weigh 1.1 grams.
Walkinshaw (1944b) reports that "when only two or three days old, the young uttered a low zeee-zee-zee-zee call when they were fed. On leaving the nest they immediately began to use a zip-ip- zip-ip-zip-ip or chip-chip-chip call."
He describes the nest-leaving as follows: "They hopped to the edge of the nest and remained there for some time. Then they moved gradually out into the branches of the nest tree. Sometimes one fell to the ground, and it was then led by one of the adults, usually the male, into a brushy area. By 10 days of age they could hop into the lower branches of bushes, where they sometimes remained for long periods on one perch. By 12 days of age they could fly a few feet, and at 14 days of age they were capable of sustained flight."
Plumages.--Dwight (1900) describes the juvenal plumage, which is acquired by a complete juvenal molt, as follows: "Above, wood-brown, grayish on nape and rump, heavily streaked with dull black, faintly tinged on scapularies and crown with chestnut. Wings and tail dull black, rectrices and primaries ashy edged, the secondaries and tertiaries chestnut edged, wing coverts and tertiaries terminally edged with buff. Ill-defined superciliary stripe, dull grayish white spotted with black. Auriculars wood-brown. Dusky loral postocular streak. Below, white, streaked except on abdomen and crissum, with dull black. Bill and feet pinkish buff, the former growing dusky and the latter wood-brown with age."
In juvenal plumage the chipping sparrow is most like the field sparrow, but can be distinguished by the fact that it is "much more heavily streaked, both above and below, than in the young field sparrow, the dark markings being much sharper and more distinctly blackish (Sutton, 1935)."
Sutton (1937) observed the plumage development and molts of a young chipping sparrow, of precisely known age, from the time it left the nest at 8 days of age until it was 8 weeks old. He summarizes the changes as follows:
The postjuvenal molt begins when the bird is about thirty days old. The postjuvenal molt thus must begin in late June and early July in young of normal first broods. . . .
The plumage worn by the eight-day-old Chipping Sparrow is not, strictly speaking, a complete plumage of any sort. Not until the bird is about three weeks old does it don its first set of lesser wing coverts. As the total skin area of the growing bird increases new rows or sets of feathers appear, particularly in the region of the lower breast and belly.
The juvenal middle and greater coverts drop out almost simultaneously when the bird is about six weeks old. Molting of the body plumage takes place much more gradually, but the streaked feathers of the under parts are all gone by the time the bird is forty-five days old.
The postjuvenal molt does not involve the remiges and rectrices, but it does involve the tertials, the dropping out of which is subsequent to that of the middle and greater coverts.
The plumage acquired by this partial molt is the first winter plumage which Dwight (1900) describes as similar to the juvenal plumage "but with the chestnut crown veiled with buff edgings and narrowly streaked with black. Below, uniform grayish white, unstreaked, washed with buff on throat and sides. Superciliary line dull white buff tinged. Loral, postocular and indistinct submalar streaks black."
The first nuptial plumage is acquired by a molt in March and April confined largely to the head, chin, and throat. This results in the chestnut crown, the white superciliary lines and the white chin with the adjacent cinerous gray characteristic of the adults (Dwight, 1900). Other changes involve increased streaking of the back brought about by abrasion and a general paling of the buff and chestnut caused by gradual fading.
Adult winter plumage is acquired by a complete postnuptial molt, and the adult nuptial plumage by a partial prenuptial molt (Dwight, 1900).
Food.--Judd (1900) examined the contents of 250 stomachs taken from March through November from New England to California. He found that for the whole sample the food was 62 percent vegetable and 38 percent animal. The vegetable component was made up largely of grass seed (48 percent of total food) which included 26 percent (of total) crab and pigeon grass seed; the rest was grain (4 percent) and a miscellany (10 percent of total) of the seeds of clover, ragweed, amaranth, wood sorrel, lambsquarters, purslane, chickweed, knotweed, and black bindweed. The animal component contained weevils (6 percent), leaf beetles (2 percent), other Coleoptera (3 percent), caterpillars (9 percent), grasshoppers (10 percent), and 8 percent made up of such organisms as leafhoppers, true bugs, ants, spiders, and parasitic wasps. He found that in June the food was 93 percent insects--63 percent grasshoppers, 25 percent caterpillars, and 6 percent leaf beetles.
At Lake Itasca in summer the chipping sparrows often fed by the doorsteps where the table cloths had been shaken, and it was supposed that it would be simple to trap them with bread crumbs or oatmeal as bait. When neither of these proved effective, we tried fine chick feed with equal lack of success. These chipping sparrows were apparently nearly exclusively insectivorous in the breeding season, for they readily enter grain-baited traps at other times. Burleigh (1958) writes, "Stoddard, in his manuscript on the bird life of Grady County, tells us that, during the late winter and early spring months from 1924 to 1930, many Chipping Sparrows were caught and banded that had entered the quail traps operated by the Co-operative Quail Investigation." Stoddard (1931) baited the traps "with a half-and-half mixture of 'baby chick' feed and 'hen chow,' or in wet weather with a combination of wheat, sorghum, millet, popcorn, and similar whole small grains that do not sour so badly."
Mrs. Louis de Kiriline Lawrence writes that she watched a pair, feeding young 9 or 10 days old, pecking at a salt block. Notes submitted by A. D. DuBois record "The chipping sparrows are frequent and welcome visitors in the vegetable garden. In the nesting season, when they have nestlings to be fed, they patrol the row or two of cabbage plants looking for and picking off the cabbage worms, the troublesome green larvae of the cabbage butterfly. A chipping sparrow that I saw eating dandelion seeds seemed to swallow the downy tufts and all."
Behavior.--On two occasions I have seen an incubating bird tumble from the nest and flutter along the ground. One nest was in the lowest limb of a white spruce at Itasca Park, 6 feet from the ground and 10 feet from the trunk. Each time I approached this nest the occupant dropped out and fluttered hesitatingly along the ground in a direction away from my approach. The second nest was about 6 feet from the ground near the top of an ornamental juniper along the west wall of a building in Delaware, Ohio. This individual behaved in the same manner as the Minnesota bird.
Cases of "flycatching" have been reported from at least two widely separated points. Laurence B. Potter writes from Eastend, Saskatchewan, "This spring I remarked for the first time chipping and clay-colored sparrows springing out from a fence in approved flycatcher style." F. H. Allen (in litt.) reports from Massachusetts: "Like so many passerine birds the chipping sparrow occasionally catches insects on the wing. On a September day I saw one associated with cedar waxwings and a phoebe that was flycatching from some telegraph wires. The chippy followed suit but always landed on the ground instead of returning to the wires."
The chipping sparrow is numbered among those birds that have been observed sparring with their reflection in a pane of glass (Forbush, 1929).
Robert A. Norris submits the following interesting note on their behavior in winter flocks: "One characteristic that I have noticed repeatedly among winter flocks of chipping sparrows is the proneness of individuals--usually but two at a time--to engage in brief, almost momentary, aerial disputes or 'clashes' involving excited call notes and agile maneuvers--sometimes upward, sometimes in other directions. While still in the air the birds separate so that their dogfight, if it may be so called, seems to end as suddenly as it begins. The reason for flight combats in chippies are not at all clear; they do not seem to be directly associated with food supply or with temporary territorial holdings. I have not observed field sparrows giving these aerial performances at any time. Indeed, these actions, if seen among members of a distant flock of small sparrows, enable one to predict with confidence that the sparrows will turn out to be chippies."
Voice.--Donald J. Borror analyzed 461 chipping sparrow songs by means of an audiospectrograph from recordings of individuals in Maine, Pennsylvania, West Virginia, Ohio, and Michigan. The following account is taken from his work (Borror, 1959):
Songs of the Chipping Sparrow. . .have been described. . .as a simple trill or rapid series of notes, all on one pitch, and of a dull and unmusical quality. The only variations mentioned are in speed ("fast" or "slow") and in the number of notes in the song. . . . Chipping Sparrow songs are generally simple trills. . . .
The individual phrases of the song contain from one to three slurred notes. The slurring is usually quite rapid, in some cases over an octave or more in 0.01 second; it is this rapid slurring of the notes that gives the song its dull and unmusical quality. The notes are usually clear, but in a few songs each phrase contains a buzzy note. The notes may be up-slurred or down- slurred (or both); the phrases in most songs contain both up-slurred and down-slurred elements.
. . .Very little variation, never more than a few thousandths of a second, was found in the length of different phrases in the same song.
. . .The number of phrases in the songs studied varied from 9 to 72, and averaged 33.31. A few songs whose phrases were two- and three-noted had the last phrase incomplete.
. . .The phrase length, measured from the beginning of one phrase to the beginning of the next, varied from 0.044 to 0.145 (average, 0.087) second; this corresponds to a variation in rate of from 22.5 to 6.9 (average, 11.5) phrases per second. . . . In general, the shorter the phrases the more phrases there were in the song. . . . The songs varied in length from 0.94 to 6.86 (average, 2.61) seconds. . . . There was no evidence in the recordings studied of any significant geographic variation in song pattern in this species.
It is interesting to note that the songs of eight individuals recorded in Mexico and analyzed by Marler and Isaac (1960) fall within the range of variation Borror found in his recordings from the northeastern United States.
Borror describes the songs of one individual which began with a short series of long phrases and then abruptly went into a series of short, more rapid phrases. For two seasons I observed a male at Lake Itasca that had the opposite pattern. He began with a series of rapid short phrases and abruptly changed to a series of longer slow phrases. The change was so marked that one observer concluded that two individuals were singing in the same tree. Forbush (1929) remarks that "rarely a bird will interpolate or add some unusual improvised musical notes."
Beginning with Audubon (1841) observers have noted that the chipping sparrow occasionally sings at night. Mr. Bent recorded the following in his notes: "May 13, Dudley St., 10 p.m. Pitchy dark--heard a chipping sparrow sing one strain." At Itasca State Park a bird not infrequently sang a single song from the ridge of our cabin roof at night.
In a letter, A. A. Saunders writes, "On a number of occasions, in the very early morning, I have heard birds singing a series of short songs, each one of eight notes, and each one beginning with a strongly accented note. This may be a sort of twilight song, but if so it is not common." This may be the same song that F. H. Allen describes when he writes, "The early morning singing of the chipping sparrow consists of a rapid repetition of much shorter songs than the songs we hear at other times. I have on at least one occasion heard this manner of singing late in the afternoon."
Field marks.--The two sexes are marked and colored alike. The species may be readily distinguished from other Spizellas by the reddish brown cap, the darker lower edge of which sharply delimits it from the whitish superciliary line, which is bordered below by the black eye line. The plain underparts are gray to grayish white. The bill is black.
The song is most apt to be confused with that of the pine warbler. Competent ornithologists have been misled by a chipping sparrow singing in a pine warbler habitat.
Enemies.--Statements on the importance of the cowbird as a factor in limiting chipping sparrow population seem to vary considerably. Friedmann (1929) lists it as one of the five species most commonly parasitized in New York State. He reports "It is an extremely common sight to see one of these familiar little birds feeding a big, clumsy Cowbird." In a study of nests in southeastern Michigan, Berger (1951a), in a small sample of eight nests, had five parasitized, while of 66 Walkinshaw (1944b) found in southwestern Michigan only three were parasitized. Sutton (1960) reports that on the George Reserve in southern Michigan he found only 1 of 38 nests with a cowbird egg in it, and although he saw one young cowbird out of the nest being fed by a chipping sparrow, he did not find a nest containing a young cowbird. He attributes the low parasitism to the fact that in the red cedars of the George Reserve the nests are very well concealed. The success of the cowbirds in chipping sparrow nests seems to be low.
About 60 percent of chipping sparrow nests are successful (Walkinshaw, 1944b, 1952) and the failures may be attributed to many different factors of which predation is only one. Snakes (Sutton, 1960), birds (Dixon, 1930), and cats (Walkinshaw, 1944b) have been observed preying on eggs or young. Maurice Broun writes me from Hawk Mountain, Pa., that "Our chipping sparrows are often victims of predation by the black and milk snakes. We have noted that when first nestings fail, the birds usually build their second nest at higher elevations."
Chipping sparrows are subject to a number of external parasites. H. S. Peters (1933) lists the following parasites collected from birds during banding : two species of lice (Philopterus subflavescues Geof., Ricinus sp.); two species of flies (Ornithoica couftueus Say, Ornithomyia avicularia Linn); one species of tick (Ixodes brunneus Koch); and two species of mites (Analgopsis sp., Liponipsus sylvarium).
A foot disease, often called "foot-pox," is common in chipping sparrows in the southeast in late winter and early spring. At Summerville, S.C., 13.6 percent of the 323 William P. Warton banded in 1929 (Warton, 1931) were afflicted, while another 9.3 percent showed evidence that they had recovered from the disease. In 1930 the disease was less prevalent, active in only 5.09 percent of the 255 birds Warton banded that year. Robert A. Norris, while banding a smaller sample, found a much higher incidence in 34 adults and first-winter birds trapped near Tifton, Ga., from Feb. 29 through Mar. 24, 1952. He reports (Norris, 1952) "Twenty seven birds or about 82%, including both age groups, were afflicted with foot-pox (epithelioma contagiosum), having discolored tumors on one or more toes and occasionally at the end of the tarsus. Some had lost a claw or two, and some parts of toes. . . . 1952 appears to be a peak year for this disease. . . . The overall average weight of 12.5 grams is very close to that of April trapped, non-diseased birds from Cleveland, Ohio (Baldwin and Kendeigh, Auk, 55:436, 1938). Both this fact and the data from Tifton suggest that, in general, diseased Chipping Sparrows weigh about the same as non-diseased ones."
Fall.--After nesting the family groups wander about feeding, usually in weedy fields, along fence rows and forest edges where they often join company with other family groups of their own species and also song sparrows and field sparrows until they form flocks of considerable size. They wander about until they are ready to migrate in late September or early October. In the North, migration usually begins in early October and the last individuals are seen in late October or the first weeks of November.
Audubon (1841) was of the opinion that this species migrated by day and he wrote: "These gentle birds migrate by day; and no sooner has October returned and mellowed the tints of the sylvan foliage than flitting before you on the road, you see family after family moving southward, chasing each other as if in play, sweeping across the path, or flocking suddenly to a tree if surprised, but almost instantly returning to the ground and resuming their line of march. At the approach of night they throw themselves into thickets of brambles, where, in company with several other species, they keep up a murmuring conversation until long after dark."
While the feeding flocks may work their way south in the manner Audubon described, Clarence Cottam (1953) describes large flocks of night migrants at the Capitol in Washington, D.C. He says: "windy night of October 23d. . .fully a thousand Chipping Sparrows were swarming in the lighted areas from the statue of Freedom on the apex of the dome, outward over the Senate and House wings and on to the lighted terrace and walks surrounding the building. . .the floodlights. . .were turned off shortly after midnight. . . . By 1:00 a.m. there was very little activity and the birds seemed to be settled for the night. Consequently the observer left, but when he returned about sunrise not a Chipping Sparrow could be found. . . . on the night of October 29th. . .another huge flock was reported at the Capitol."
A. A. Saunders writes that "birds rarely sing in the fall, in late September or early October." Forbush (1929) says that the young males begin to sing in August.
Winter.--Most chipping sparrows winter in the southern states. A few stragglers often linger along the coast as far north as New Hampshire and inland as far north as southern Ohio, Indiana, and Oklahoma. They do not remain as far north as the field sparrow, and they do not ordinarily winter in large numbers north of the North Carolina coast. From this point on south, along the east coast, they outnumber the field sparrow on the coastal plain, but are not so common on the piedmont and are generally absent from the western North Carolina and South Carolina highlands. They become less common down the Florida peninsula. They seem to avoid the southern tip of Florida and the coast line of the gulf states, although they winter in some numbers on the coastal plain just inland from the coast and as far north as northern Alabama and southern Arkansas.
The first winter visitors arrive on the coastal plain of
Georgia in late October or the first days of November or at about
the time that the last ones are leaving the North (Burleigh,
Chipping Sparrow* Spizella passerina [Eastern and Canadian Chipping Sparrows]
*Original Source: Bent, Arthur Cleveland. 1968. Smithsonian Institution United States National Museum Bulletin 237 (Part 2): 1166-1184. United States Government Printing Office