Description is incapable of conveying to your mind any accurate idea of the notes of this bird, much less of the feelings which they excite. Were I to tell you that they are, in fact, not strictly musical, you might be disappointed. The cry consists of three distinct notes, the first and last of which are emphatical and sonorous, the intermediate one less so. These three notes are preceded by a low cluck, which seems preparatory to the others, and which is only heard when one is near the bird. A fancied resemblance which its notes have to the syllables whip-poor-will, has given rise to the common name of the bird.
This species is easily shot, when the moon is shining, and the night clear, as you may then approach it without much caution. It is, however, difficult to hit it on wing, on account of the zig-zag lines in which it flies, as well as the late hour at which it leaves its resting-place. It is seldom killed, however, being too small to be sought as an article of food, although its flesh is savoury, and it is too harmless to excite dislike.
It deposits its eggs about the middle of May, on the bare ground, or on dry leaves, in the most retired parts of the thickets which it frequents. They are always two in number, of a short elliptical form, much rounded, and nearly equal at both ends, of a greenish-white colour, spotted and blotched with bluish-grey, and light brown. The young burst the shell in fourteen days after the commencement of incubation, and look at first like a mouldy and almost shapeless mass, of a yellowish colour. When first able to fly they are of a brown colour, interspersed with patches of buff, the brown being already beautifully sprinkled with darker dots and zig-zag lines. They attain their full plumage before they depart, with their parents, for the south. I think their southward migration, which is performed by night, must be very rapid, as I have never found any of these birds in Louisiana at that season, whereas they proceed slowly on their return in spring. Both birds sit on the eggs, and feed the young for a long time after they are able to fly, either on wing, in the manner of the Common House Swallow, or while perched on the fences, wood-piles, or houses. The food of the young at first consists of ants, and partially digested beetles and large moths, which the parents disgorge; but at the end of a fortnight the parents present the food whole to the young, which then swallow it with ease.
Much has been said respecting the difference existing between the Whip-poor-will and the Night Hawk for the purpose of shewing them to be distinct species. On this subject I shall only say, that although I have known both birds from my early youth, I have seldom seen a farmer or even a boy in the United States, who did not know the difference between them.
It is a remarkable fact that even the largest moths on which the Whip-poor-will feeds, are always swallowed tail foremost, and when swallowed, the wings and legs are found closely laid together, and as if partially glued by the saliva or gastric juice of the bird. The act of deglutition must be greatly aided by the long bristly feathers of the upper mandible, as these no doubt force the wings of the insects close together, before they enter the mouth.
I have represented a male and two females, as well as some of the insects on which they feed. The former are placed on a branch of Red Oak, that tree being abundant on the skirts of the Kentucky Barrens, where the Whip-poor-will is most plentiful.
Caprimulgus vociferus, Ch. Bonaparte, Synops. of Birds of the United States, p. 62.
Whip-poor-will, Caprimulgus vociferus, Wils. Amer. Ornith. vol. v. p. 71. Pl. 41. fig. 1. Male, fig. 2. Female, fig. 3. Young.
Adult Male. Plate LXXXII. Fig. 1.
Bill extremely short, feeble, opening to beyond the eyes, making the mouth, when open, of enormous dimensions; upper mandible arched in its dorsal outline, very broad at the base, suddenly contracted at the tip, which is compressed and rather obtuse; lower mandible decurved. Nostrils basal, oval, prominent, covered above by a membrane. Head disproportionately large. Eyes and ears very large. Neck short. Body rather slender. Feet very short; tarsus partly feathered, anteriorly scutellate below; fore toes three, connected to the second joint by membranes, scutellate above; claws depressed, arched, that of the middle toe with the inner edge expanded and pectinate.