The general habits of the Nightjar are quite as remarkable as its note. It feeds on the wing, chasing and capturing the various moths, beetles, and other insects that fly abroad by night. It may be seen wheeling round the branches of some tree, the oak being a special favourite, sometimes circling round it, and sometimes rising high in the air, and the next moment skimming along the ground. Suddenly it will disappear, and next moment its long trilling cry is heard from among the branches of the tree round which it has been flying. To see it while singing is almost impossible, for it has a habit of sitting longitudinally on the branch, and not across it, like most birds, so that the outline of its body cannot be distinguished from that of the bough on which it is seated. As suddenly as it began, the sound ceases, and simultaneously the bird may be seen wheeling again through the air with its noiseless flight.
Being a very bold bird, and not much afraid of man, it allows a careful observer to watch its movements clearly. I have often stood close to the tree round which several Nightjars were circling, and seen them chase their prey to the ground within a yard or two of the spot on which I was standing. The flight of the Nightjar is singularly graceful. Swift as the swallow itself, it presents a command of wing that is really wonderful, gliding through the air with consummate ease, wheeling and doubling in pursuit of some active moth, whose white wings glitter against the dark background, while the sober plumage of its pursuer is scarcely visible, passing often within a few feet of the spectator, and yet not a sound or a rustle will reach his ears. Sometimes the bird is said to strike its wings together over its back, so as to produce a sharp snapping sound, intended to express anger at the presence of the intruder. I never, however, heard this sound, though I have watched the bird so often.
Owing to the soft plumage with which it is clad, this bird, like the owls, looks larger than really is the case. It is between ten and eleven inches in length, with an expanse of wing of twenty inches, and yet weighs rather less than three ounces. Its large mouth, like that of the swallow tribe, opens as far as the eyes, and is furnished with a set of vibrissæ or bristles, which remind the observer of the "whale-bone" which is set on the jaw of the Greenland whale. The scientific name of the bird is Caprimulgus Europæus.
THE SWALLOW.
Identification of the smaller birds—Oriental indifference to natural history—Use of collective terms—The Swallow—Signification of the word Deror—The Bird of Liberty—Swallows and Swifts—The Sunbirds and Bee-eaters—Variety of small birds found in Palestine—The Swallows of Palestine—Swallows protected by man in various countries—Nesting of the Swallow—The Rufous Swallow and Martin—The Sis or Swift—Various species of Swift inhabiting the Holy Land—Talmudical notions of the Swift or Swallow—The leper and his offering—The cooking pot and the sacrificial vessel—Signification of the word Tzippor-deror.
Difficult as is the identification of the mammalia mentioned in the Bible, that of the birds is much more intricate.
Some of the larger birds can be identified with tolerable certainty, but when we come to the smaller and less conspicuous species, we are at once lost in uncertainty, and at the best can only offer conjectures. The fact is, the Jews of old had no idea of discriminating between the smaller birds, unless they happened to be tolerably conspicuous by plumage or by voice. We need not be much surprised at this. The Orientals of the present day do precisely the same thing, and not only fail to discriminate between the smaller birds, but absolutely have no names for them.
By them, the shrikes, the swallows, the starlings, the thrushes, the larks, the warblers, and all the smaller birds, are called by a common title, derived from the twittering sound of their voices, only one or two of them having any distinctive titles. They look upon the birds much as persons ignorant of entomology look at a collection of moths. There is not much difficulty in discriminating between the great hawk-moths, and perhaps in giving a name to one or two of them which are specially noticeable for any peculiarity of form or colour; but when they come to the "Rustics," the "Carpets," the "Wainscots," and similar groups, they are utterly lost; and, though they may be able to see the characteristic marks when the moths are placed side by side, they are incapable of distinguishing them separately, and, to their uneducated eyes, twenty or thirty species appear absolutely alike.
I believe that there is no country where a knowledge of practical natural history is so widely extended as in England, and yet how few educated persons are there who, if taken along a country lane, can name the commonest weed or insect, or distinguish between a sparrow, a linnet, a hedge-sparrow, and a chaffinch. Nay, how many are there who, if challenged even to repeat the names of twelve little birds, would be unable to do so without some consideration, much less to know them if the birds were placed before them.