Chapter D: B. Burrows, in some notes sent to Major Bendire (1895) says (2)

On the second day the young frequently appeared in the open and at such times often pecked at the mother’s beak as if recognizing it to be the door of a well-filled cupboard. The young had not yet been fed, as they were still dependent on the yolk provided by the egg and stored in their bodies at the time of hatching. The female remained with the young throughout the day, whereas the male did not make his appearance until 8:50 in the evening. He announced his arrival with a sharp call as he landed on the roof. His call was immediately answered by the female, whereupon he made his way to the nest and without ceremony or delay delivered the first food received by the young.

I was not prepared to see the male feed the young because the male of the preceding summer (another individual) never assisted in the care of the young. This striking difference in individual behavior emphasizes the point that it is not safe to generalize on observations of a single individual.

The next morning the female was brooding her young, and being accustomed to my daily presence she allowed me to reach under her breast to remove the young without exhibiting the least bit of fear. A female nesting on another roof when visited for the first time scooted away hurriedly, fluttered helplessly on the roof, enacting a perfect imitation of a crippled bird, a ruse to attract my attention away from her young. When I followed her she quickly flew away. On subsequent visits this bird stood her ground, elevated her wings in an upright position, and hissed at me in defiance of my approach.

The following notes are from observations made of the young that were hatched on the high-school roof the preceding year (1921). The female of that year was the same bird that nested there in 1922. The identity of the female was established by banding and also by a slight deformity of the maxilla, the tip of which was broken off. The males of the two broods were different individuals.

The young were fed during the early morning before sunrise and again in the evening after sunset. During the heat of the day, when the temperature frequently went soaring above 110° F., the young kept well concealed under the breast of the brooding bird in close contact to her abdominal air sacs. When the temperature was less torrid the young peeked their heads through the feathers and often came out entirely. At such times they sometimes amused themselves by picking at the mother’s beak and rectal bristles. If the annoyance became too great the female would thrust her head beneath her breast. The young then proceeded to pick at the feathers of her crown and nape.

The female left the nest regularly about 8:30 p. m. (daylight saving time) to obtain food for herself and young. In the case of this brood the female delivered all the food required by the young. The food was delivered by the process of regurgitation. The beak of the female was thrust well into the large and widely distended mouth of the young when the transfer of food was made. After feeding, the adult brooded her young in the earlier stages of their development.

For the first three days the young remained near the spot where they had been hatched, but on the fourth day after a heavy rain they had moved to a slightly raised portion of the roof, which was free from excessive dampness. The female never left the young during a rain at this stage of their growth, even if it meant depriving them of food. The male regularly visited the roof early in the morning and again in the evening throughout the breeding season, but he was never seen to deliver food to the young. The male was usually stationed on the roof when the female was away and thus served as a watchdog in her absence. More than once he was called upon to chase away a strange nighthawk that had inadvertently alighted in his territory on the high-school roof.

On the fifth day (June 29) the young had wandered to the southern end of the building where the shadow of the roof wall protected them from the direct rays of the burning sun. The heat during the middle of the day was frequently excessive. On July 7, when the young were 13 days old, a thermometer placed on the gravel of the roof registered 140° F. The heat was too much for one of the young, which succumbed and was found dead near the middle of the roof. Its fellow nestling, hidden in the shadow of the roof wall and behind a clay ventilating pipe, escaped death but was in a serious condition. A sponge soaked with cold water was placed near the youngster, whereupon it ignored its parent to enjoy the comfort provided by the cool sponge. This act probably aided the survival of the young nighthawk through the remainder of the record-breaking hot day.

As the nighthawk grew older he became very aggressive and pugnacious and never hesitated to pester his mother whenever he was hungry. At times he seemed mischievous. It was not a rare experience to see him crouch under his mother’s breast and then by standing up quickly and rigidly topple his mother so that she was forced to extend her wings to keep from falling over. During the period of the rapid growth of the wing feathers the youngster was continually extending and stretching his wings as if to relieve the uncomfortable feeling caused by growing pains.

When the young nighthawk was three weeks old he was able to make short flights from one place to another on the gravel roof. At this stage of his growth he had become so large that it was difficult for the female to cover him adequately while brooding. This was strikingly demonstrated on the evening of July 17, when he was 23 days old. The mother had left him alone on the roof while she was away on her regular evening search for food. It was so cool and damp that the young bird uttered notes that clearly indicated discomfort. I placed him in a woolen bag, and this, combined with the warmth of my hands, was very satisfying, as indicated by his change to notes of contentment. He remained there in comfort until his mother alighted on the roof and gave the characteristic call note, announcing supper. The little nighthawk struggled out of my bag and ran directly to his mother to be fed. After he was gorged with insects, the female attempted to brood him, but to her apparent dismay he rushed back to the woolen bag, clearly recognizing that I could do a much better job at brooding.

On July 19, when the nighthawk was 25 days old, I discovered that he was no longer solely dependent on his parent for food. I found him busily engaged catching some white moths that had collected about a drain pipe of the roof. He was flying this way and that, catching the moths with great delight. As I sat there watching I chanced to pull a small handkerchief from my pocket, whereupon he dashed at the white object with the ferociousness of a tiger. Evidently to the nighthawk this was some giant moth large enough to provide for an entire meal.

The female now made frequent attempts to entice the young bird away from the roof by first offering food but flying away before it was delivered. The youngster would follow her in extended flights but invariably returned to the roof.

On July 24, when the bird was 30 days old, the female was photographed with the young for the last time. Thereafter she forsook her offspring for a roost in the nearby elm tree. She then visited the roof only for short intervals at feeding times. On each successive day the young bird took longer and longer flights, and each day I anticipated it would be my last opportunity to photograph and to observe him. Much to my delight he continued to return, seeming to enjoy my companionship.

On August 15 he left with the other nighthawks of the vicinity on their migration to the south. This unusual experience of having the bird return to the roof gave me an unprecedented opportunity to make a continuous set of daily observations and measurements of a nighthawk living under normal natural conditions up to the time it was 52 days of age. By this time the growth of the juvenal plumage was completed and exchanged in part for the first winter plumage.

_Plumages._--On the first day the young are able to stand upright and are very active from the time of hatching. The eyes are open, iris bluish black; skin darkly pigmented darker above than below; bill “pale mouse gray”; tarsus and toes brownish drab. Down present on both dorsal and ventral parts of the body. Down of the ventral tracts pale gray shading to “pallid neutral gray” on the belly; chin gray, malar stripes and patch on the throat “dark mouse gray,” approaching black. Upper parts mottled and marbled, made up of patches of pale gray and “dark mouse gray.” In the region of the nape and scapulars the down has a distinct “pale olive-buff” tint. At the base of the beak the down has a tinge of buff. A circular area about the anus, the outer part of the shanks, and fore arm have patches of darker colored down. Patterns of dark and white vary considerably in different young. The average length of the down on the various parts of the body varies as follows: Crown 9, base of bill 4, region over eye 6, throat 12, belly 15, wing 11, and region of anus 8 millimeters.

On the third day the color of the bill has changed to a “deep neutral gray,” and the tarsus and toes become a dusky drab. Down at the base of the beak, scapular region, and irregular patches of the back has faded from the colors present in the day-old chick to a “tilleul buff.” Iris is now a clear brown instead of the bluish black of the freshly hatched chick.

At the age of 10 days the tarsus and toes are “deep Quaker drab,” bill “dark neutral gray,” eyelids “light neutral gray.” Exposed portions of the eyes are noticeably greater. Down of the back much worn and matted down, the feather papillae in the region of the crown, wing coverts, scapulars, and rump now more conspicuous than the down. The tips of the feathers of the back are unsheathed and exhibit a black and cinnamon color. The color pattern of the back is completely lost since the appearance of the feather papillae and their unsheathed tips. The papillae of the tail feathers are only 8 millimeters long and as yet do not show through the down. The feather papillae of the head and tail are the last to unsheath.

In chicks 13 days old the “pinkish cinnamon” of the tips of the feathers of the dorsal tracts has faded to a “pinkish buff,” and some of the feathers approach a “tilleul buff.” Freshly unsheathed feathers of the crown are “pinkish cinnamon.” Black markings have faded to a “fuscous-black” or “dusky neutral gray”; yellowish color of the breast feathers of the younger stages now faded to gray tinged with yellow. The juvenal plumage is rapidly replacing the natal down in all parts of the body. The yellowish-gray breast feathers are barred with “dusky neutral gray.” As previously noted, one of the two birds died from exposure to great heat at this time and the remaining descriptions are based on one bird.

At the age of 15 days the down is ragged in appearance but is still prominent on the breast, sides of the head, wing coverts, and region of the tail. The down is worn off the feathers in the region of the crown and scapulars. Feathers of all tracts of the juvenal plumage are partially unsheathed. When the young are handled there are numerous particles of the feather sheaths that scale off. The wings exhibit a marked development. The tips of the under tail coverts recently unsheathed are ivory colored. The down persisting at the tips of the feathers comes off with the slightest pull. The pupil of the eye appears bluish black and the iris has changed to a “Van Dyke brown.”

When 17 days old the sixth primary has now proceeded with unsheathing so that the white patch is 13 millimeters in extent. Tarsus and toes are “blackish plumbeous,” bill is a “dusky purplish gray,” eyelids are “dark olive-gray”; otherwise the markings are similar to those of the 15-day-old bird.

When 20 days old a relatively small amount of down remains, but a few filaments can be seen on the tips of some of the crown feathers, sides of neck, and breast. Feathers of the wings are growing fast and are so heavy from the large amount of blood and large sheaths that the wings rest on the surface of the roof, the bird being unable to support them. The wings are frequently outstretched, apparently to relieve the uncomfortable sensation produced by rapid growth of the feathers. Bristlelike feathers now appear around the base of the beak. The fifth primary is grown so that the white patch is beginning to unsheath, and the base of the fourth primary shows white area on sheath, which is destined to form part of the white patch on the wing of the fully grown young. The white on the sixth primary made its first appearance in the 17-day-old chick.

At this age the crown is “dusky neutral gray” or black, the feathers tipped, barred, and spotted with “vinaceous-buff”; some of the tips approach “avellaneous.” The feathers of the upper parts are dark, or dusky, neutral gray variously mottled with shades of gray and “avellaneous” many of the feathers tipped with “pinkish buff.” Auriculars “light cinnamon-buff” and black, tipped with lighter shades. Primaries and secondaries blackish warm gray, some of the feathers having an olivaceous-black appearance. All the remiges are tipped with “tilleul buff” or “vinaceous-buff.” Some of the secondaries and inner primaries spotted with “vinaceous-buff.” Coverts of primaries unspotted “blackish mouse gray” or black. Coverts of secondaries spotted with “tilleul buff” and “vinaceous-buff.” Lesser wing coverts variously mottled with colors mentioned above. Feathers of the breast barred with “dark mouse gray” and shades of gray and white. Throat and chin with a crescentic band of feathers, which are barred with dark gray and white, the white predominating. Band of feathers along the edge of mandible extending below the eyes to the auriculars “neutral gray” and marked with “vinaceous-buff.” Under tail coverts “cartridge buff,” narrowly barred with black. Middle of the belly a heavy mat of down. Eyelids “light olive-gray,” tarsus deep metal gray.

At 25 days the down has been lost, except that of the middle of the belly and small patches on the legs above the heels.

At 28 days the colorings are about as described for the 20-day-old chick, but the colors are subdued and faded because of exposure to the intense sunlight. The down is now entirely replaced by the feathers of the juvenal plumage. Although the outer primaries are only partially unsheathed, the young bird is capable of long flights and frequently leaves the roof, but invariably returns.

At 30 days the secondaries and the primaries, except the outer ones, are now unsheathed. The barred feathers lining the wings are now in process of unsheathing.

At 35 days the prevailing color of the upper parts is olivaceous-black, glossed with greenish, but this base color is very much broken by irregular markings, spotting, and marbling of buffy gray and whitish; many of the larger spots approach a light vinaceous-buff, which is especially evident on the crown. Spots of the crown are larger than those of the back. The throat patch now is clear white, an indication of its sex.

At 40 days, all the primaries except the outer two are completely unsheathed. The white patch of the second to fifth unsheathed, that of the first is 11 millimeters.

The bird, although able to fly as well as an adult, returned to the roof each day and allowed me to make daily measurements and weighings without the least resistance. It never attempted to run or fly away when I approached to pick it up. When I arrived on the roof wall it gave a series of calls, which seems to be a sign of recognition. The bird placed before me in a natural sitting pose measured 187 millimeters from the tip of the bill to the tip of the wings. Distance from level of the crown to the board on which it is seated is 90 millimeters. Tip of tail to front of toe in natural position 150, and tip of folded wing to toe 165 millimeters.

The bird at this age is very active and vivacious and captures all its own food. It offers no difficulty for me to capture it for measurements and poses perfectly for photographs.

On Monday, August 15, there was a great flight and departure of nighthawks, and after that date the nighthawk was seen no more. Presumably it went southward on its migration. The bird was 52 days old, and I had an unexcelled opportunity to observe the bird up to the time of the completion of its growth.

The completed juvenal plumages of both sexes is similar to that of the adult female except that the throat patch is not so well defined; in some it is replaced by blackish and buffy bars. The barring of the underparts is more extensive and the coloration in general is paler than that of the adults. There are whitish tips on all the primaries.

The postnatal molt has already been described in detail under the account of the young. There is a partial molt that does not include the wings and tail in September. There is a partial or complete prenuptial molt in spring when the young attain the plumage of the adult. The adults have a complete postnuptial molt before they return for their nesting activities the following year. I have not been able to ascertain the time of the postnuptial molt.

Albinistic phases of plumage, in which there is an absence of dark pigment, may appear in any species of birds. W. A. Strother (1886) reports a perfect albino taken at Lynchburg, Va.

_Food._--The nighthawk is insectivorous in its eating habits. Since the major part of the insects it destroys are destructive to useful vegetation or are otherwise adverse to human welfare, the nighthawk ranks high in the list of birds beneficial to man.

The nighthawk captures the insects chiefly during its flight. The birds sweep up in their capacious mouths all types of insects from the large moths and beetles to the tiniest of flies and mosquitoes. Some of the stomachs examined have contained no less than 50 different species of insects, and some of the smaller insects are at times represented by thousands of individuals.

One of the most conspicuous elements of the food is flying ants. In the examination of 87 nighthawk stomachs, the United States Biological Survey reports that ants comprised nearly one-fourth of the total food eaten by the birds. In 24 of the stomachs the number of ants ranged from 200 to 1,800, and in all the stomachs examined there were not less than 20,000 ants (Beal, 1897). In the stomach of a nighthawk that met with accidental death at Brunswick, Maine, on August 20, 1925, there were 2,175 ants. The mass and weight of these insects were so great that they constituted a serious handicap and probably a factor in the bird’s untimely ending. Charles Drury (1887) obtained a specimen in August that contained 320 insects, chiefly winged ants. W. L. McAtee (1926) found more than one hundred carpenter ants (_Camponotus herculeanus_) in one nighthawk stomach. In most all instances the ants captured are the mating winged individuals, which fly in immense swarms during the late summer. These ants are killed at a time when they are preparing to propagate their kind, and hence the death of every female means the destruction of thousands of the next generation.

According to examinations of the United States Biological Survey (Beal, McAtee, and Kalmbach, 1916) beetles comprised one-fifth of the food eaten by 87 nighthawks examined. May beetles, dung beetles, and others of the leaf-chafer family were in greatest numbers. Beal (1897) reported finding the remains of 34 May beetles (_Phyllophaga_) in a single nighthawk stomach, in another 23, and in a third 17. In the stomach contents of one specimen no less than 17 species of beetles were identified. Chester Lamb (1912) reports that all nighthawks collected by him had eaten enormous quantities of beetles. Thomas G. Gentry (1877) reports eight species of beetles in food examined by him. McAtee (1926) reports various leaf chafers, sawyers, wood borers, bark beetles, weevils, and plant lice in the food eaten by nighthawks in the course of his study of the relation of birds to woodlots in New York State. In the examination of hundreds of droppings of nighthawks obtained from various nesting sites chiefly at Brunswick, Maine, a large percentage of the identifiable remains consisted of parts of various species of beetles.

Nighthawks, especially in the Middle West, have been known to eat a considerable number of grasshoppers and locusts. According to Ernest Harold Baynes (1915) seven Nebraska specimens were found to have eaten 348 Rocky Mountain locusts; five specimens collected in Indiana reported by A. W. Butler (1898) had eaten 9 grasshoppers, 19 beetles, 23 Heteroptera, and 4 Neuroptera. B. H. Warren (1890) reported that grasshoppers were an important element of the food eaten by nighthawks collected in Pennsylvania. F. E. L. Beal (1897) states that one nighthawk contained the remains of 60 grasshoppers. A male killed on July 7, 1882, was reported by Everett Smith (1883) to have “an ichneumon fly, a black cricket, about twenty small grasshoppers, and many small, hard insects” in its crop.

Flies, plant lice, and mosquitoes frequently form an important element of the food of the nighthawk. A nighthawk examined by the Biological Survey had eaten more than 300 mosquitoes, and E. H. Forbush (1907) reports finding 500 mosquitoes in the stomach of one bird. McAtee (1926) reports that he found 650 plant lice in the stomach of a single nighthawk. Phoebe Knappen (1934) found stone flies in 21 nighthawks. The insects were chiefly adults but also a few larvae, nymphs, and eggs were present.

In the South various observers have noted that the nighthawk is an important factor in the control of the cotton-boll weevil. F. H. Herrick (1901) writes of a nighthawk that had been feeding on fireflies; the wide open mouth of an adult observed feeding its young was brilliantly illuminated like a spacious apartment all aglow with electricity. F. H. Carpenter (1886) relates a unique experience with nighthawks that darted at the artificial flies on his line when he was casting for trout. It is not an unusual experience to see nighthawks after dusk flying about electric lights of city streets (Knowlton, 1896) or about campfires of remote districts where they capture myriads of insects attracted by the lights.

During the migration nighthawks frequently fly near the ground and at such times may take advantage of any insects that appear in their path. During an afternoon late in August I observed a flight of several hundred nighthawks near Urbana, Ill. As I sat in a car alongside a large meadow I noticed that the birds were ravenously feasting on grasshoppers. Some of the birds lingered long enough to capture half a dozen of the insects before passing on to make place for other nighthawks in the migrating procession. A. Dawes DuBois, of Excelsior, Minn., relates a similar experience he had in the vicinity of Salt Creek, Logan County, Ill., as follows: “At dusk on the evening of May 22, 1913, as I walked along a cloverfield, we witnessed an assemblage of nighthawks in pursuit of low-flying insects. They skimmed over the clover like swallows; and their dusky forms were so numerous that they seemed to be weaving an intricate pattern in the gray twilight. They were so intent on their bountiful repast that they paid no heed to our presence, but sometimes darted past us only a few feet away.”

Nighthawks not only capture food on the wing, but they also have been observed to drink, in the manner of swallows, as they skim near the surface of the water of lakes and streams. F. Stephens (1913) observed a nighthawk drinking from a watering trough. This bird dropped its lower mandible into the water, rippling the surface of the water as it passed along. A. Dawes DuBois writes of the following experience he had at Springfield, Ill., on July 29, 1923: “Mr. R. B. Horsfall and I were walking along the margin of a small pond when a nighthawk swooped down, touched the surface of the water and rose again; but we could not tell whether it was scooping up a floating insect or a drink of water.”

_Voice._--The nighthawk has no claim as a singer, but nevertheless its notes are of great interest and attract fully as much attention as the voices of our more gifted songsters.

The loud piercing calls uttered by the nighthawk during flight are simple yet, like all bird notes, extremely difficult to represent in written words so as to enable a reader unfamiliar with them to gain a clear conception of their character and quality. This fact is at once emphasized if we compare the interpretations of a few of the many authors who have attempted a written version of its calls. For example to C. G. Abbott (1914) it sounds like a “grating ‘beedz, beedz,’” and to Charles Bendire (1895) it is a querulous and a squeaky note resembling “aek-aek, aek-aek” or “speek-speek, speek-speek.” W. E. Grover describes this note as a sharp “mueike”; and E. H. Forbush (1907) states that “the note is s-k-i-r-k or s-c-a-i-p-e, a little like the call of Wilson’s snipe,--rather a startling squeak when heard close at hand.” W. L. Dawson (1903) interprets the note as “mizard, mizard,” and E. H. Eaton (1914) describes it as a “loud nasal ‘peent, peent.’” N. S. Goss (1891) writes that its voice is a “squeak” or a “pe-up” note, and Arkansas Hoosier (1890) states that “the note is best produced by speaking the word ‘beard’ in a whisper.” To G. R. Mayfield (1921) the call is a shrill “B-e-e-r-b” and to H. Nehrling it is “Brirrr-brirrr.” H. Tullsen (1911) interprets it as a sharp penetrating “Spe-eak,” and H. H. Bailey (1913) thinks it sounds like “Queek-queek.”

There was probably only the slightest variation in the notes of the different nighthawks as heard by the authors mentioned above, yet how strikingly different are the interpretations as represented in the written or printed words. The note described above is the one most frequently heard, and it is uttered independently of the seasons. It is the note that announces the arrival of the nighthawk in spring, and it is the call uttered at the time the nighthawks are congregating in fall in preparation for their departure to the south. I have been unable to ascertain whether this call is heard at their winter home in South America.

Frequently, during the courtship season, the males in their competition for a mate vigorously pursue each other. At such times both birds utter a series of sharply accented calls recorded in my field notes as resembling _Dick-a-dick-a-dick-dick-dick-dick-dick_, given in rapid succession.

There is another note of the nighthawk very different in character, an aeolian sound, produced by the rush of air through the primaries of the wings at the termination of the extraordinary downward plunge executed during the courtship season. In order to see this performance and to hear this peculiar and unique note to the best advantage it is necessary to visit the vicinity of the nesting site. Alexander Wilson (1828) described this note as a “loud booming sound very much resembling that produced by blowing strongly into the bunghole of an empty hogshead.” E. H. Eaton (1914) offers a modification of Wilson’s description in stating that the note is like that produced “by blowing across an empty bottle.” T. G. Gentry (1877) describes it as a sound resembling that “produced by a tense cord set in vibration by a sudden gust of wind.” T. Jasper (1878) states that it is a hollow whir like the rapid turning of a spinning wheel, and F. A. Hartman (1914) describes it as a “guttural ‘woof.’” The note reminds W. A. Stearns (1883) of the sound produced by a bellowing bull. In my field notes I have described this note as a muffled _wr-r,r,r,r,r-oonk_, but sometimes more nearly approaching _sw-r,r,r,r-ooonk_, the last syllable decidedly accented and produced with great resonance. There is nothing about this note suggesting an explosive boom or bellowing.

It has long ago been well established that this peculiar note is not a vocal sound but one produced by the vibration of the primaries. As keen an observer as Alexander Wilson (1828) stated that it is “produced by the sudden expansion of his capacious mouth.” Others shared Wilson’s view or thought that it was a sound produced by the syrinx. After one has observed the performance it can be readily understood how such an erroneous interpretation was made by the earlier observers. The plunge takes place so quickly that it is only by repeated observations made under the most favorable conditions that the observer is convinced that the primaries are involved. Audubon (1840) was the first to arrive at a correct explanation. He writes that the source of the singular noise is “the concussion caused, at the time the bird passes the centre of its plunge by the new position of its wings, which are now brought almost instantly to the wind, like the sails of a ship suddenly thrown back.” This observation with variation of its details has been made by numerous subsequent observers. J. B. Canfield (1902) gives a description of the performance as follows: “He suddenly paused and came soaring toward me like an arrow. About fifty feet in front of me his wings were lowered below his body, throwing them forward with the flight feathers spread wide apart * * * His speed was so great that the flight feathers vibrated like a loosely-stretched rubber band when snapped with the fingers. This performance was repeated in front, back, and beside me twelve times in all, never more than fifty feet away, and as near as fifteen. In all cases the wings were in the same position, and his mouth never open.” F. A. Hartman (1914) writes, “It is very evident that the mouth plays no part, otherwise the sound would be produced at other times [than on the downward glide]. * * * The bird threw its wings far to the front at the end of his downward glide, so that the uppermost quill feathers were pointed exactly in the direction of his glide. Going at such headlong speed, these quill feathers when thrown edgewise to the air vibrated strongly, causing the ‘woof’.” Alden H. Miller (1925) while at Camp Lewis, Wash., during June and July succeeded in attracting nighthawks within 10 feet of himself by merely waving his hat in the air. He noticed that if the wings, during the downward plunge, were held in the upturned V-shaped position, a normal pose when soaring, no boom was heard, but when the wings were bent downward near the end of the dive the boom sound was produced. The intensity of the sound, according to Mr. Miller, is more or less proportional to the speed attained. The main explosive boom seems to be preceded by a brief, lesser vibrating sound, which bursts forth into the full bellow. Both parts seem to have a distinct element of pitch, but the latter part is lower, with greater resonance and depth of quality.

The sound produced by the wings described above is a part of the courtship performance and is usually produced near the nesting site. After the young no longer require the constant attention of both parents, the male loses the glamour of romance and performs less frequently and soon after ceases almost entirely until the courtship season of another year. However, birds migrating in August sometimes “boom.”

Another note associated with the courtship season is a guttural call uttered only when the male is at rest and in the presence of the female. It may be described as an oft repeated _auk, auk, auk_ or _awk, awk, awk_. This note is produced by the syrinx, but as it is uttered the bill is tightly closed and the gular membrane is tightly distended each time the note is produced. The distension is caused by the expulsion of air from the respiratory system. The distended membrane, although feathered, acts as a resonator and modifies the note, giving it a peculiar quality. Such a mechanism is present in other birds. It is especially highly developed in the prairie chicken, in which large lateral vocal sacs are present that give the “booming” notes of this grouse great carrying power.

The notes of the female nighthawk are simple calls uttered in response to the those of the male or of the young. She may utter a purring, pacifying note when brooding the young, but often these notes are so weak that they cannot be heard by the observer unless he is stationed very near in a blind.

_Game._--Today we do not think of the nighthawk as a game bird, yet 60 years ago large numbers of them were killed by gunners and sportsmen, especially in the Southern States. M. G. Elzey, writing on September 18, 1876, stated: “Bull-bats (nighthawks) are the best of the minor game of this country for sport or table; have been very abundant and in superb condition here (Blacksburg, Virginia) for the past two weeks. I have killed several hundred. On one occasion took out 28 cartridges and brought in 23 birds besides 2 which fell out of bounds and were recovered by boys. Killed 17 in succession. The bats are quite as fat and better game than the reed birds.” Dr. E. Sterling (1885) wrote: “Their rapid and irregular flight makes them a difficult mark for the young sportsman to practice on, as he never fails to make a target of them when the opportunity offers. I can now understand the object for which this bird was created.” Dr. F. M. Chapman (1888), writing of conditions at Gainesville, Fla., stated, “‘Bat’ shooting is here a popular pastime, great numbers being killed for food, and in August, when the birds have gathered in flocks, favorite fields may be occupied at nightfall by as many as a dozen shooters.” Stockard (1905) lamented the fact that the birds “are foolishly slaughtered by pseudo-sportsmen who shoot them merely to watch the bird’s graceful fall or to improve their skill as marksmen.”

The practice of killing nighthawks was stopped through laws and by educational methods initiated by the National Association of Audubon Societies. William Dutcher (1902), in writing of conditions in Florida, stated, “It is believed, on very satisfactory evidence that the new law has stopped to a large degree the disgraceful practice of shooting ‘bull-bats’ or Nighthawks (_Chordeiles virginianus_) for sport.” Bird-Lore for September-October 1903 published the following note: “The Night-hawk, or Bullbat, has been so long considered a legitimate target for shotgun practice, in the south, that a report of prosecution for killing these birds at Greensboro, North Carolina, marks a new era of bird protection in our southern states.”

_Enemies._--The greatest enemy of the nighthawk has been man. In the past great numbers of the birds were killed for food and often for mere sport or for satisfying a lust for killing. This was especially true in the Southern States, where the birds were slaughtered during the great flights of the annual migrations.

Nighthawks nesting on the ground are subject to the same enemies experienced by other species of ground-nesting birds. Night hawks nesting on roofs are usually free from such molestation, but Albert F. Ganier informs me that he has known of sparrow hawks invading the cities and preying upon the nighthawks, especially the young. Cats and dogs become enemies of the city dwellers in the event the young leave the nest prematurely and land on the streets below.

Nighthawks have a remarkable protective coloration and have developed methods of deception such as imitating a wounded individual when an enemy approaches the nesting site. At times they assume an attitude of aggression; i. e., raising their elongated wings in a vertical position and hissing in defiance at an intruder.

DISTRIBUTION

_Range._--The Western Hemisphere generally, from Yukon to Patagonia.

_Breeding range._--The breeding range of the nighthawk extends =north= to Yukon (Sixty-mile River and probably Lapierres House); Mackenzie probably Fort Goodhope, (probably Fort Franklin, Fort Resolution, and Hill Island Lake); northern Saskatchewan (Methye Portage, Stanley, and Reindeer River); northern Manitoba (probably Du Brochet Lake, Grand Rapids, and probably Churchill); northern Ontario (Martin Falls, probably Fort Albany, and probably Moose Factory); and Quebec (Lake Mistassini, Godbout, and Mingan Island). The =eastern= boundary of the range extends from this point southward through the coastal regions of the Maritime Provinces, the Eastern United States, the Bahama Islands (Nassau), to Puerto Rico (Mayaguez). =South= to Puerto Rico (Mayaguez); Haiti (Hinche and Jean Rubel); Jamaica (Port Henderson and Grand Cayman); Cuba (Isle of Pines); southern Texas (Brownsville, San Antonio, Kerrville, and Pecos); Chihuahua (Babicora); Sonora (Oposura and Los Nogales); and southern California (San Bernardino Mountains and Pine Knot). =West= to California (Pine Knot, Mona Lake, Grass Valley, and Eureka); western Oregon (Medford, Eugene, Corvallis, Portland, and St. Helen); western Washington (Bumping Lake, Gig Harbor, Seattle, and Blaine); British Columbia (Errington, Courtenay, Fort St. James, and Hazleton); southeastern Alaska (Wrangell); and western Yukon (Carcross, Whitehorse, and Sixty-mile River).

_Winter range._--When the numerical abundance and extensive breeding range of this species are considered, it is surprising that knowledge concerning the winter range should be extremely limited. It seems certain, however, that it is entirely in South America =north= to Colombia (Antioquia); Venezuela (Orinoco Valley); and central Brazil (Matto Grosso). =East= to southeastern Brazil (Matto Grosso, São Paulo, and Rio de Janeiro); Uruguay (Concepcion); and Argentina (Barracas and La Plata). =South= to central Argentina (La Plata and Cordova). =West= to Argentina (Cordova, Santiago, Tucuman, and the Gran Chaco); western Paraguay (Asuncion); western Brazil (Chapada); western Ecuador (Portoviejo); and western Colombia (Bogota and Antioquia).

The outline presented is for the entire species, which has, however, been separated into seven subspecies, or geographic races. The typical eastern nighthawk (_C. m. minor_) breeds in the eastern part of the continent west to the edge of the Great Plains from Oklahoma to Minnesota and in Canada to British Columbia and southern Yukon; the Florida nighthawk (_C. m. chapmani_) nests in the Gulf and South Atlantic States north to Arkansas, southern Illinois, central Alabama, and central North Carolina and west to eastern Texas; Howell’s nighthawk (_C. m. howelli_) breeds in the southern part of the Great Plains region from northeastern Utah and western Kansas south to Oklahoma, central Texas, and New Mexico; Cherrie’s nighthawk (_C. m. aserriensis_) is found in south-central Texas and the Mexican state of Tamaulipas; Sennett’s nighthawk (_C. m. sennetti_) occupies a breeding range in the northern Great Plains from northeastern Montana and North Dakota south to eastern Wyoming, Nebraska, and northwestern Iowa; the western nighthawk (_C. m. henryi_) breeds in southwestern Colorado, eastern Arizona, New Mexico, Chihuahua, and Sonora; and the Pacific nighthawk (_C. m. hesperis_) nests in the western part of the continent from southeastern British Columbia and California east to southwestern Saskatchewan, northwestern Wyoming, and central Utah. In no case is it possible to indicate subspecific winter ranges, but it appears that all forms winter together in South America.

_Spring migration._--Early dates of spring arrival in North America are: Florida--Orlando, March 20; Palma Sola, March 29; Pensacola, April 8. Georgia--Savannah, April 1; Kirkwood, April 19. South Carolina--Frogmore, April 12; Columbia, April 17. North Carolina--Hendersonville, April 13; Raleigh, April 15. Virginia--Variety Mills, April 10; New Market, April 24. District of Columbia--Washington, April 18. Maryland--Mardela Springs, April 19. Pennsylvania--Philadelphia, April 23; Beaver, April 27. New Jersey--Morristown, May 7. New York--New York City, April 20; Ballston Spa, April 29; Rochester, May 7. Connecticut--Hartford, April 24; Jewett City, May 6. Massachusetts--Harvard, April 19; Amherst, May 10. Vermont--St. Johnsbury, May 6; Rutland, May 12. New Hampshire--South Manchester, May 2; Concord, May 14. Maine--Dover-Foxcroft, April 29; South Portland, May 1. New Brunswick--St. Johns, May 13. Quebec--Quebec City, May 4; Montreal, May 9. Louisiana--New Orleans, April 8. Mississippi--Biloxi, April 8; Rodney, April 19. Arkansas--Monticello, April 11. Tennessee--Athens, April 20. Kentucky--Lexington, April 19; Eubank, April 23. Missouri--St. Louis, April 22; Kansas City, May 2. Illinois--Chicago, April 21; Odin, April 27. Indiana--La Fayette, May 1; Fort Wayne, May 6. Ohio--Cleveland, April 20; Oberlin, April 21. Michigan--Sault Ste. Marie, April 30; Detroit, May 1. Ontario--Toronto, April 30; Ottawa, May 9. Iowa--Keokuk, April 23; National, May 6. Wisconsin--Madison, May 2; Milwaukee, May 3. Minnesota--Minneapolis, April 26; Lanesboro, May 7. Kansas--Onaga, April 30; Manhattan, May 1. Nebraska--Omaha, May 8; Red Cloud, May 3. South Dakota--Vermillion, May 10; Forestburg, May 16. North Dakota--Grand Forks, May 1; Argusville, May 18. Manitoba--Margaret, May 10; Aweme, May 12. Texas--San Antonio, April 2; Kerrville, April 22. Colorado--Denver, May 4; Yuma, May 9. Wyoming--Cheyenne, May 8; Torrington, May 24. Montana--Great Falls, May 15; Columbia Falls, May 29. Saskatchewan--Indian Head, May 18; Eastend, May 26. Arizona--Oracle, April 20; Santa Rita Mountains, May 1. Utah--Kobe Valley, May 24. Idaho--Ruper, May 18; Meridian, May 20. Alberta--Flagstaff, May 27; Banff, May 28. California--Red Bluff, April 1; San Diego, April 22; Eureka, May 7. Oregon--Coos Bay, May 1; Klamath Lake, May 26. Washington--Tacoma, May 22. British Columbia--Burrard Inlet, May 26; Okanagan Landing, June 1.

_Fall migration._--Late dates of fall departure are: British Columbia--Okanagan Landing, September 15. Washington--Tacoma, September 11. Oregon--Weston, September 9. California--San Francisco, September 21. Los Angeles County, October 27. Alberta--Banff, September 17. Idaho--Meridian, September 15; Rupert, September 16. Arizona--Chin Lee, September 25. Saskatchewan--Eastend, September 15. Montana--Columbia Falls, September 28; Great Falls, October 6. Wyoming--Yellowstone Park, September 15. Colorado--Yuma, September 25; Denver, October 14. Texas--Taylor, October 2; Palo Pinto, October 21; Corpus Christi, November 6. Manitoba--Winnipeg, September 19; Aweme, September 24. North Dakota--Charlson, September 22. South Dakota--Forestburg, September 21; Sioux Falls, October 1. Nebraska--Blue Springs, October 5; Red Cloud, October 10. Kansas--Topeka, October 6; Onaga, October 22. Minnesota--Minneapolis, September 15; Lanesboro, September 30. Wisconsin--Madison, October 6. Iowa--National, September 30; Keokuk, October 8. Ontario--Ottawa, September 23; Toronto, October 11. Michigan--Detroit, September 17. Ohio--Wauseon, September 30; Cleveland, October 8. Illinois--Chicago, October 7; Odin, October 14. Missouri--Concordia, October 18. Kentucky--Eubank, October 9. Tennessee--Athens, October 5. Arkansas--Rogers, October 4; Dardanelle, October 25. Louisiana--New Orleans, November 3. Quebec--Montreal, September 17. New Brunswick--St. Johns, September 27. Maine--Portland, September 26; Livermore Falls, October 2; Vermont--Rutland, September 12; St. Johnsbury, September 13. Massachusetts--Amherst, September 27; Harvard, October 3. Connecticut--Hartford, September 26. New York--Rochester, September 28; New York City, October 1. New Jersey--Morristown, October 11. Pennsylvania--Renovo, September 23; Philadelphia, October 15. District of Columbia--Washington, October 11. North Carolina--Raleigh, October 6; Hendersonville, October 13. South Carolina--Columbia, October 22; Mount Pleasant, November 9. Alabama--Autaugaville, October 11. Florida--Orlando, October 13; Pensacola, October 20.

_Casual records._--With a range that covers most of the Western Hemisphere, it is not surprising that comparatively few nighthawks should be recorded beyond the known normal limits. A specimen was taken by an Eskimo at Allakaket, on the Koyukuk River in northern Alaska, late in September or early in October 1923. One was seen at Grand Falls, Labrador, on May 31, 1895, and a specimen was collected at Makkovik in June 1929. The species is a fairly regular visitor at Bermuda during migration, sometimes being very common.

_Egg dates._--California: 36 records, March 20 to July 26; 18 records, June 18 to July 1, indicating the height of the season.

Colorado: 11 records, May 31 to July 18.

Florida: 40 records, April 7 to July 17; 20 records, May 15 to June 3.

Georgia: 16 records, May 17 to July 13; 8 records, May 24 to June 10.

Kansas: 28 records, May 31 to July 7; 14 records, June 13 to 28.

Maine: 30 records, May 24 to July 3.

Michigan: 13 records, May 15 to July 19; 7 records, June 2 to July 3.

New York: 9 records, May 29 to July 8.

South Dakota: 9 records, June 10 to July 1.

Texas (Brownsville region): 28 records, April 5 to June 28; 14 records, May 10 to June 5.

Texas (elsewhere): 62 records, April 11 to July 29; 31 records, May 15 to June 1.

CHORDEILES MINOR HENRYI Cassin

WESTERN NIGHTHAWK

HABITS

Dr. Gross has contributed such a full life history of the eastern nighthawk that it hardly seems necessary to say much about the other subspecies, as they are all much alike in general habits.

The above name formerly covered most of the western races that are now recognized as subspecifically distinct. This race is now supposed to be confined to the southern Rocky Mountains and adjacent high plains, from Colorado southward into Mexico, Chihuahua, and Sonora. Other races are recognized in the more lowland plains.

Cassin (1862), in his original description of this bird, named it as a species in honor of Dr. T. Charlton Henry and said of it: “This bird may be distinguished from other American species by its color, which is lighter and of a different style of variegation, the prevailing tone being a dull, pale reddish and yellowish, somewhat approaching what is called buff or drab color. It is larger than _Chordeiles virginianus_.”

Dr. Harry C. Oberholser (1914), in comparing it with some more recently described races, says that it is “similar to _Chordeiles virginianus howelli_, but upper surface, both ground color and markings, much darker, the latter more tawny and also coarser; lower parts posteriorly more buffy, anteriorly more rufescent.” It is lighter and more brownish than _hesperis_, darker and more rufescent than _sennetti_, and lighter and more brownish than _virginianus_.

_Nesting._--The nesting habits of the western nighthawk are very similar to those of the eastern bird. Dr. Edgar A. Mearns (1890) says of his experience with it in the mountains of Arizona: “I have never known this species to infringe on the territory of the Texan Nighthawk during the breeding season; each keeps to its own ground, the latter being confined to the region below the pines, and the former residing in the pines and spruces, breeding in great numbers in these limited areas. * * * Two fresh eggs were taken at Flagstaff on June 18, 1887, in a level place, bestrewn with volcanic scoria, beneath the pines.”

We found only the western nighthawk in the mountains and only the Texas nighthawk in the lower valleys. After I left, Mr. Willard found a nest on July 9, 1922, at an elevation of 5,200 feet in the Huachuca Mountains, Arizona. The eggs were lying in the open on gravelly soil; just before the eggs were taken, a heavy hailstorm occurred, during which nearly 6 inches of hail fell; evidently the female had covered the eggs during the storm, or the eggs might have been broken.

_Eggs._--The two eggs of the western nighthawk are indistinguishable from those of other nighthawks, showing the same variations. In shape they are between oval and elliptical-oval, usually with little or no gloss, though some incubated eggs are quite glossy. The ground color is dull white, or grayish white, rarely “dark” or “deep olive-buff”. Usually they are quite evenly marked; some are closely sprinkled with fine dots, but oftener they are covered with small spots, streaks, or small blotches of “olive-brown,” “sepia,” or “mummy brown”; occasional eggs are marked with brighter browns, such as “russet” or “hazel”; very often there are underlying spots or blotches of “pale Quaker drab.” The measurements of 19 eggs average 30.2 by 21.6 millimeters; the eggs showing the four extremes measure =33.0= by 21.1, 30.0 by =23.1=, =27.3= by 21.5, and 27.5 by =19.7= millimeters.

_Food._--Mrs. Bailey (1928) says of the food of the western nighthawk in New Mexico: “Ants in large proportion and also beetles which are the adult forms of noted pests. Specimens taken at Fort Stanton--caddice flies and gnats, together with injurious insects, including ants, plant bugs, leaf hoppers, crane flies, click beetles, wood-boring and engraver beetles, clover root weevils, and nut weevils.”

Beal, McAtee, and Kalmbach (1916) say that these birds are “so expert in flight that no insects can escape them. They sweep up in their capacious mouths everything from the largest moths and dragon flies to the tiniest ants and gnats, and in this way sometimes gather most remarkable collections of insects. Several stomachs have contained fifty or more different kinds, and the number of individuals may run into the thousands.”

Dr. Mearns (1890) writes:

In our summer camp, near the summit of the Mogollon
Mountains, a small beetle was annoyingly abundant, flying
into our tents in great numbers during the day, and at
night swarming around our log fires. As the twilight
gathered, hundreds of these Nighthawks appeared upon the
scene, preying upon the troublesome insects. Careless of
our presence at the fires and of the noisy hilarity of
camp, they flitted through the smoke with astonishing
freedom from diffidence, capturing myriads of the hated
beetles, as they passed and repassed above, between, and
around us, until their flickering forms were as familiar as
the stirring of the pine boughs overhead, and the fanning
of their wings almost as little heeded.

_Field marks._--There are two other races of this species, _hesperis_ and _howelli_, that are likely to be seen within the range of the western nighthawk on migrations; these three races are not easy to recognize in life, though _henryi_ is lighter than _hesperis_ and darker than _howelli_.

The western nighthawk can be distinguished in flight from the Texas nighthawk by the position of the white wing band; in the western nighthawk this band is about halfway between the bend of the wing and the tip; in the Texas nighthawk the white wing band is nearer the tip than the bend of the wing.

_Fall._--Mrs. Bailey (1928) says that after the breeding season and in the fall the western nighthawks range up to higher altitudes in the mountains, even as high as 12,600 feet. “They all desert the State for the winter, beginning their southward journey soon after the middle of summer. They are most numerous in migration during August and have nearly all left [New Mexico] by the end of September. * * * On the return journey in the spring they are among the very latest migrants, seldom reaching northern New Mexico before May 10.”

CHORDEILES MINOR CHAPMANI Coues

FLORIDA NIGHTHAWK

HABITS

This small race occupies the southern Atlantic and Gulf States, from North Carolina to eastern Texas. In general appearance it differs but little from the eastern nighthawk, except in size. Dr. H. C. Oberholser (1914) characterizes it as “like _Chordeiles virginianus virginianus_, but decidedly smaller; upper parts averaging a little more mottled and spotted with whitish and buffy, particularly on back, wings, and scapulars, and the ground color averaging slightly less deeply blackish (more grayish or brownish); posterior lower parts usually more purely white.”

Nighthawks are tender birds and spend their winters in South America, from Colombia to northern Argentina. Even in Florida they usually do not arrive until some time in April. Arthur H. Howell (1932) says of the haunts of the Florida race: “The Florida Nighthawk frequents open pine forests, old fields, pastures, prairies, cultivated lands, marshes, and ocean beaches. Although most active early in the morning and late in the evening, the birds frequently may be seen flying about in search of food in bright sunshine.”

_Nesting._--Mr. Howell (1932) says on this subject: “The two eggs are deposited on the ground, with no semblance of a nest, in an open situation, often in a pasture, broomsedge field, or wood lot, or in palmetto scrub in open forest or on the prairie, or sometimes among sparse grasses on or near the ocean beaches.”

Major Bendire (1895) says that Dr. William L. Ralph took several sets of eggs in Putnam County, Fla., and that here “during the breeding season at least, the Florida Nighthawk frequents mainly low, flat pine woods, especially such as have recently been burnt over, the eggs generally lying on the bare ground. Sandy soil seems to be preferred for nesting places. One set of eggs was found by him under a small orange tree in an orange grove on the side of a sandy hill; three others were taken in flat pine woods, and in one instance the eggs laid on a few fragments of charcoal left where a fallen tree had been partly burnt, between the remaining part of the tree and the stump, about 3 feet from each.”

On Cat Island, off the coast of Mississippi, I found the Florida nighthawk very common in the extensive forest of tall, long-leaf pines, with which the island is largely covered. Here, on June 16, 1910, I saw two pairs with young, the old birds fluttering along the ground to toll us away from their little ones; and I found one nest with two eggs on the bare, sandy ground among the pines.