They perfer the lowest branches, under the brinks, and well sheltered from the wind ; and it is remarkable, that the branches on which they commonly sit during the night wither away. In our climate it sometimes happens that, after their arrival, a long tract of north-easte ly wind prevails, which so benumbs the insect tribes, that thousands of swallows perish for want of food. Frisch informs us, that of all the swallows, this species has a cry most approaching to a song, though it consists only of three tones, terminated by a finale, which rises to a fourth, and it is little varied. Besides these inflexions of voice. however, it has its note of invitation, of pleasure, of fear, of resentment, that by which the mother warts the young of danger, &c. It rouses the house-martin, and other small birds, by announcing the approach of birds of prey ; for, as soon as a hawk or owl appears, the sw al low calls, with a shrill alarming voice, all his fellows and the martins about him, which pursue, in a body, and strike and buffet their adversary, until they have driven him from the place, darting down on his bat k, and "ising in a perpendicular line in perfect security. It will also sound the alarm, and strike at cats, when they climb on the roofs of houses, or otherwise approach the nest.
Previous to their departure, the chimney swallows con gregate in flocks of three or four hundred, on houses or trees, and usually steal off in the night to avoid the birds of prey, which seldom fail to harass them in their route. Mr. White relates, that as he was travelling very early on a morning of Michaelmas day, and arriving on a large heath, or common, he could discern, as a thick mist which had obscured the prospect began to break away, great numbers of swallows, clustering on the stunted shrubs and bushes, as if they had roosted there during the night. But, as soon as the air became clear and pleasant, they were all on the wing at once, and, by a placid and easy flight, proceeded on southwards in the direction of the sea; after which he could perceive no more flocks, but only occasional stragglers. About Oxford, they are usually seen later than elsewhere in England. owing, as has been supposed, to the number of massy buildings at that place, and to the many streams with which it is sur rounded. Frisch more than once saw these birds take their departure in broad day, and Hebert, about the time of their retreat, observed parties of forty or fifty gliding aloft in the air, and maintaining a flight, not only much more elevated than ordinary, but also more uniform and steady. On such occasions their progress is always in a southerly direction, availing themselves, as much as pos sible, of favourable winds ; and, when no obstacles in ter fete, they usually arrive in Africa in the first week of October. If checked by a south-east wind, they halt, like the other birds of passage, on the islands that lie in their track. Adanson witnessed the arrival of parties of them, on the coast of Senegal, on the sixth of October, at half past six o'clock in the evening, and found them to be real European swallows; and he subsequently ascertain; ed that they are never seen in Senegal, except in autumn and winter. He adds, that they never breed tnere; and Frisch accordingly remarks, that young swallows never arrive in Europe in the spring. Though generally mi gratory, even in Greece and Asia some will remain dur ing the winter, especially in the mild latitudes in which insects abound, as, for example, in the }hetes Islands, and on the coast of Genoa, where they pass the night in the open country on the orange trees.
Like the carrier pigeons, chimney swallows have been sometimes employed to convey important intelligence. For this purpose the mother is taken from her eggs, and carried to the place whence the news are to be sent ; and Y 2 there a thread is tied to her feet, with the number of knots and the colour previously concerted. Immediately on being liberated, she flies back to her brood, and thus bears the tidings with incredible expedition.
Did swallows fail to make their appearance for a single summer, our houses and crops would be overrun with in sects, and not merely annoyance, but famine, might ensue. Hence the impolicy, as well as the cruelty, of destroying multitudes of these harmless birds, either for the table, or for improving the practical skill of the sportsman.
H. urbica,Lin. &c. Martin, Common Martin, Martlet, Martinet, House Martin, it Swallow. Black-blue above, under parts and rump white ; tail feathers without spots. The black of the female is less decided, and the white less pure. The tail is blue-black, and forked ; the legs are covered with a white down ; and the claws are white. It is about five inches and a half in length, and rather inferior in size to the chimney swallow. It would he superfluous to describe more particularly a bird which is so familiar to our observation. The young have all the upper parts of a blackish-brown. Accidental varieties also occur ; but some writers have confounded with these different species which are natives of North America.
The martin, which seems to be intermediate between the chimney swallow and the swift, is allied to the former by its note, the familiarity of its manners, and the mode of constructing its nest, and to the latter, by the con formation of its feet, its capability of turning the hind toe forwards, for its clinging to walls, by its crawling rather than walking, and by its flying in greater flocks than usual during heavy showers of rain. Martins are more
chilly than chimney swallows, courting, even in the mid dle of summer, the first rays of the sun, when assem bled on the projections of towers or elevated houses, where they also occasionally seek for shelter in autumn ; and, when cold winds or rains prevail, they press close on one another, and are sometimes so benumbed as to he caught by the hand. When molested in their asylum, however, they fly with considerable rapidity; and although they are sensible to even slight degrees of cold, yet they survive that of frost, or, if they perish under it, it is probably from defect of food. On the occurrence of cold weather, they usually frequent the margins of pools and marshes, with a view no doubt to catch any little prey which they can then procure, and which they would in vain search for elsewhere, and it is usually in such situa tions that they are found stiff or dead. Their first annual appearance in this island is about the 16th of April, and they usually sport and play about for nearly a month be fore they commence the important task of nidification. They delight to build their nests against the crags of pre cipices that overhang lakes, and seldom breed near our houses, if they can find a convenient situation elsewhere; yet their choice often appears to be capricious, and they will sometimes begin several structures, and leave them unfinished; but when one has been completed in a shelter ed situation, if not invaded or accidentally destroyed, it suffices for several seasons. As the martin often builds against a perpendicular wall, without any ledge underneath, it employs every sagacious effort to get the first founda tion firmly fixed, so as to sustain the superstructure with safety. On this occasion the bird not only clings with its claws, but partly supports itself by strongly inclining its tail against the wall, and, thus fixed, it plasters the mate rials into the face of the brick or stone. But that this piece of workmanship may not., when soft, incline down by its own weight, the provident architect labours at it only in the morning, and thus gives it sufficient time to dry and harden. It may be seen at work before four o'clock, plastering with its bill, and moving the head with quick vibrations. About half inch of the fabric seems to be a sufficient layer for a day, until, in the course of ten or twelve days, or if the builders are many, in half that time, a hemispherical nest is formed, with a small aperture to wards the top. The shell, or crust, is a sort of rustic work, full of knobs on the outside, composed of earth or mud, picked up from the borders of stagnant waters, or the fresh morning casts of worms; the middle is strength ened by an intermixture of chips of straw ; and the in side is rendered soft and warm by a lining of grasses and feathers, particularly those of the goose, and sometimes by a bed of moss, interwoven with wool, the whole form ing a strong, compact, and comfortable abode for the pa rents and the young. Attentive observers have remark ed that these birds carry the mortar both with their bill and their toes, but that they plaster only with the former. On some occasions, particularly when the nest has been accidentally demolished, it is reared again in a short time by the active co-operation of many individuals; hut some times, also, several appear to be as assiduous in pulling down as others are in rearing the fabric, a circumstance which Montbeillard insinuates may be the effect of jea lousy. The common house sparrow not unfrequentl) seizes on the outwork of the nest, before it is completed, and adapts it to its own accommodation, after banishing the owner. But such invasions are not always submitted to without a struggle, and sometimes they are very successful ly repelled. The Jesuit, Batgowiski, was an eye-witness of a sparrow thus taking possession of a martin's nest, and obstinately resisting the united efforts of a group of these birds, which the despoiled owner had summoned to her aid, when they at length immured the usurper, by building up the entrance with the same mortar of which the nest was composed; and Linne alleges that similar examples might be quoted. The young martins are sometimes hatched as early as the 15th of June. The first hatch consists of five white eggs, with a dusky ring near the large end, the second of three or four, and the third, when it takes place, of two or three. During incubation, the male seldom re moves from his mate, but watches for her safety and that of the young brood, impetuously darting on birds that ap proach too near. After the eggs are hatched, poth parents fetch food to their tender offspring, and seem to treat them with the most affectionate concern. The young, on at taining their full growth, become impatient to confine ment, and sit all day with their heads out at the entrance, where the dams, by clinging to the nest, supply them with food from morning to night. After this they are fed by the parems en the wing ; but this feat is performed in so quick a flight, that a person must attend very exactly to the motions of the birds before he can perceive it. As soon as the young are capable of providing for themselves, the dam repairs the nest for a second family. The first flight then associate in large groups, and may be seen, on summer mornings and evenings, clustering and hovering around towers and steeples, and on the roofs of churches and houses.