The night-hawk and the whippoorwill are often confounded by persons of inaccurate habits of observation. It is true, both birds are members of the goatsucker family; but they belong to entirely different genera, and are therefore of much more distant kin than many people suppose. The whippoorwill is a forest bird, while the night-hawk prefers the open country. Besides, the whippoorwill is decidedly nocturnal in his habits, making the woods ring at night, as every one knows, with his weird, flutelike melody; whereas the night-hawk is a bird of the day and evening. Then, a peculiar mark of the night-hawk is the round white spot on his wings, visible on the under surface as he performs his wonderful feats overhead,—a mark that does not distinguish his woodland relative.

As a rule, the gloaming is the favorite time for the night-hawk’s wing-exercises; then he may be seen whirling, curveting, mounting, and plunging, often at a dizzy height, gathering his supper of insects as he flies; but his petulant call is often heard at other hours of the day, perhaps at noon when the sun is shining with fierce warmth. Even during a shower he seems to be fond of haunting the cloudy canopy, toying with the wind.

His call, as he tilts overhead, is difficult to represent phonetically, both the vowels and consonants being provokingly elusive and hard to catch. To me he seems usually to say Spe-ah. Sometimes the S appears to be omitted, or is enunciated very slightly, while at other times his call seems to have a decidedly sibilant beginning. On several occasions he seemed to pronounce the syllable Scape.

I had often watched the marvellous flight of these birds, as they passed like living silhouettes across the sky; but they had always seemed so shy and unapproachable that, prior to the summer of 1891, I had despaired of ever finding a night-hawk’s nest. However, one evening in June, while stalking about in the marsh, I suddenly became aware of a large bird fluttering uneasily about me in the gathering darkness. Presently it was joined by its mate, and then the two birds circled and hovered about, often coming into uncomfortable proximity with my head, and muttering under their breath, Chuckle! chuckle! Several times one of them alighted for a few moments on the rail-fence near by, and then resumed its circular flight. Even in the darkness I recognized that my uncanny companions were night-hawks, and felt convinced that there must be a nest in the neighborhood, or they would not display so much anxiety. It was too late to discover their secret that evening, and, besides, I really felt a slight chill creeping up my back, with those dark, ghostly forms wheeling about my head, and so I went reluctantly home.

Two days later I found time to visit the marsh. On reaching the spot where the two birds had been seen, presto! a dark feathered form started up before me from the ground. It was the female night-hawk; and there on the damp earth, without the least trace of a nest or a covering of any kind, lay two eggs. At last I had found a night-hawk’s nest! The ground-color of the eggs, which were quite large, was of a dirty bluish-gray cast, mottled and clouded with darker gray and brown.

The behavior of the mother bird was curious. She had fluttered away a few rods, pretending to be hurt, and then dropped into the grass. On my driving her from her hiding-place, she rose in the air and began to hover about above my head, and then, to my utter surprise, she swooped down toward me savagely, as if she really had a mind to attack me. As I walked away, she seemed to grow angrier and bolder, making a swift dash at me every few minutes, and actually coming so near my head as to cause me involuntarily to raise my cane in self-defence. A quaver of uneasiness went through me. I really believe she would have struck me had I given her sufficient provocation. There was a brisk shower falling at the time, and so, fearing the eggs might become addled, I hurried to the remote end of the marsh. Suddenly my feathered pursuer disappeared. Wondering if she had resumed her place on the nest, I sauntered back to settle the doubt, but presently espied her sitting lengthwise on a top rail of the fence, while her eggs lay unprotected in the rain. Her dark, mottled form and sleepy, half-closed eyes made a quaint picture. I slowly withdrew, and as long as I could see her with my glass, she kept her perch on the rail without moving a pinion.

On the twenty-third of June another call was made on the night-hawk family, when I found two odd-looking bairns in the nest, if nest it could be called. They were covered with soft down, the black and white of which presented a wavy appearance. Their short, thick bills were covered with a speckled fuzz, except the tips. I stooped down and smoothed their downy backs with my hand, but there was no expression of fear in their sluggish eyes.

Both parents were present on the twenty-sixth of June. For a while the male bird pursued his mate savagely through the air, as if venting on her his anger at my intrusion, and then, mounting far up toward the sky and poising a moment, he plunged toward the earth with a velocity that made my head dizzy, checking himself, as is his wont, with a loud resounding Bo-o-m-m. The female again pursued her unwelcome visitor, swooping so near my head two or three times that I could have reached her with my cane. The cock bird, curiously enough, never displayed so much courage, but kept at a safe distance.

On the twenty-ninth the young birds had been moved about a half rod from the original site of the nest, and hopped off awkwardly into the grass when I tried to clasp them with my hand. The benedict was absent this time, and was never seen on any of my subsequent visits while the young birds were fledging. By the first of July the bantlings hopped about in a lively manner at my approach to their domicile, and wheezed in a frightened way, spreading out their mottled pinions. On the seventh of July neither of the parents was to be seen, and the youngsters sat so cosily side by side on the ground that I had not the heart to disturb their slumbers. Approaching cautiously on the tenth, I almost stepped on the mother bird before she flew up. At the same moment both young birds started from the ground, and fluttered away in different directions on their untried wings, their flight being awkward and labored. A few weeks later four night-hawks were circling about above the marsh,—no doubt the family that had been affording me such an interesting study. What was my surprise when one of them resented my presence by swooping down toward me, as the female had done a few weeks before!

Reference has already been made incidentally to the night-hawk’s curious habit of “booming,” as it is called. This sound is always produced as he plunges in an almost perpendicular course from a dizzy height,—or, more correctly, at the end of that headlong plunge, just as he sweeps around in a graceful curve. There is something almost sepulchral about the reverberating sound. How it is produced is a problem over which there has been no small amount of discussion in ornithological circles. But after considerable study of this queer performance, I am persuaded that it is a vocal outburst, produced either for its musical effect (though it is far from musical), or else to give vent to the bird’s exuberance of feeling as he makes his swift descent.

His thick, curved bill seems admirably adapted to produce this sound, as do also his arched throat and neck. It has seemed to me, too, that his mandibles fly open at the moment the boom is heard, although I cannot be sure such is the case. Besides, the peculiar chuckle, previously referred to, had about it a quality of sound suggestive of kinship with the bird’s resounding boom. The hollow, wheezy alarm-call of the young birds, heard on several of my visits to the nest in the marsh, corroborates this theory. But there is still further proof that this hypothesis is correct. The night-hawk often makes his headlong plunge without booming at all, but merely utters his ordinary rasping, aerial call, which has been translated by the syllable Spe-ah. Then he sometimes combines the two calls, and on such occasions both of the sounds are uttered with a diminished loudness, as one would expect if both are vocal performances, but as one would not expect if the booming were made by the concussion of the bird’s wings with the resisting air, as some ornithologists suppose. The female sometimes booms, but her voice obviously lacks the strong, resounding quality that characterizes the voice of her liege lord.