Kitabı oku: «Nests and Eggs of Birds of The United States», sayfa 19

Plate XXXVIII. – CHÆTURA PELASGICA, (Linn.) Baird. – Chimney Swift

This species chiefly confines its migrations to the eastern portions of North America, from the Atlantic westward to the eastern base of the Rocky Mountains, and northward to the 50th parallel of latitude. In the fur-bearing countries it is probably a stranger, as no mention is made of it by Dr. Richardson in his explorations. Mr. Say met with it at Pembina, on the Red River, in Northern Minnesota; Mr. Allen, in great abundance, in Kansas; but it is doubtful as to its occurrence in New Mexico, notwithstanding the high authority of Dr. Woodhouse, as later observers are silent upon the subject. It has also been claimed by the last-mentioned traveler as being found in parts of Texas, but Mr. Dresser was unable to take it, and it does not appear that it has ever been met with by the naturalists of any of our Western expeditions. The accounts given by early writers of its presence along the Pacific region, it is now decided, pertain not to this species, but to a distinct and closely allied one. Respecting its winter-quarters we are in the dark. It is not likely that it remains in any portion of the United States during the autumnal and brumal months, not to any great extent, if it does at all, as it has been observed by Allen entering Florida during the latter days of March. Lawrence, Salvin and Sclater, as well as other writers of note on the birds of Mexico, Central America and the West Indies, make no mention of it. Its southern journey usually occurs about the middle of September, seldom later, and is performed with so much silence and suddenness, that we are only made aware of the vacancy which their departure has produced, by the missing of their confused yet pleasant chatterings at morn and night.

Their vernal advent is marked with the same quietness, and is as much a source of mystery and surprise.

Upon its arrival in the United States late in March, it diffuses itself in various directions throughout the country, reaching the Central and Northern States about the middle of April usually, but, sometimes, when the season has been very much retarded, not before the beginning of the following month. Its entrance into Canada is not looked for until near the close of April – the birds apparently timing their movements with the sun's northward advancement. From Virginia to Canada, along the Atlantic seaboard, and the same is true of our Western States, where the presence of man is seen and felt, these dusky denizens of the air are wont to take up their abode. The chimneys of our houses, especially those that' are not called into constant requisition, afford them convenient and comfortable quarters. So accustomed to their odd little ways and notions have we become, that on each recurrence of the breeding-season we naturally look for their coming with as much interest and pleasure as to that of a long absent friend. Their jolly, sociable disposition wins our regard and esteem, and has so completely interwoven their fortunes with our own, that their loss would be keenly felt and universally bewailed. In habits they are widely different from their trans-Atlantic brethren, who display considerable shyness, and breed in caves, or ruined or deserted dwellings.

Since the occupancy of this country by civilized beings, a most wonderful change has been effected in their behavior. Their primitive breeding places have been exchanged for the cosy, soot-begrimmed chimney. To be sure there are localities where breeding is still carried on in hollow trees as of yore, but such places are now but occasionally occupied in the older parts of the country, and merely for roosting purposes. In certain portions of New Brunswick, according to Mr. George A. Boardman, birds still nest in decayed tree-hollows. Even where chimneys are to be found individuals have been known to select places remote therefrom. The writer last mentioned once met with a nest that was built against a board in an old log-house. It was not the lack of a chimney that conduced to this peculiar deviation, as we are led to infer of the existence of one somewhat remotely situated from what that observer says. Where there is no danger to be apprehended from enemies, a position like the one described, affords the requisite advantages. In buildings that are freely used by man, persistence in this habit might be attended with results, which would be escaped by nidification in chimneys. In Southeastern Illinois Mr. Ridgway discovered a nest in a hollow sycamore-tree, and also another securely fastened to a plank of an out-building. Mr. Allen met it in Kansas, breeding in hollow trees, for which it seemed to manifest a decided preference. In long-settled sections the species has been forced by circumstances to resort to chimneys, or else abandon the country. In but a single instance have we known from actual experience the nest to be built against the rafter of a deserted out-building.

Nesting usually commences within a week after the birds have reached the accustomed haunts. Whether mating is accomplished preparatory to leaving their southern homes, or subsequent thereto, we are not prepared to assert, but incline to the belief that they arrive already paired, since we have never been able to observe the sexes engaged in their amours. Perhaps these are performed within the sheltering walls of the flues which they choose for their homes. The labor of nest-building requires the united efforts of the builders for three days. The structure is a rather curious and remarkable affair. Its composition consists of small twigs, nearly uniform in dimensions, which are severed from the living branches of trees, by the birds while upon wing, with considerable dexterity and adroitness. They sweep upon the coveted twig much after the fashion of a hawk in rushing upon its prey. These twigs are fastened to each other by the saliva of the builders, and by the same cement the entire fabric is made to adhere to the side of the chimney in which it is placed. This saliva, after a slight exposure, hardens into a glue-like material, which becomes as firm as the branches it joins together. In separating these nests from their reposing surfaces we have even known fragments of the bricks to give way, rather than the cementing substance. When rendered moist by long-continued rains, they often become precipitated to the bottom of the chimney solely by the weight of their own contents. In such emergencies the young cling with considerable tenacity to the chimney-side by means of bill and claw. In configuration the nest resembles a neat, semi-circular basket, and measures about three and a half inches in diameter, one and a half in width, and about one in depth. Some are found to exceed the above dimensions, and others to fall considerably short of them. Building operations are ordinarily entered into during the early morning hours while the air is cool, the birds then working with praiseworthy diligence, but seldom during the hot, summer noontide. All the time the work is going on the builders are the happiest of creatures, and judging from the continual chatter which they make, there is never an angry word spoken, nor a quarrel indulged in with each other, or with any of their near neighbors who occupy the same chimney. Their lives seem to be as gay and felicitous as the days are long.

A few days elapse after the completion of the fabric, not usually more than two, in which mutual congratulations are passed. Then comes the drama in which the female is the principal actor – namely, the laying of the eggs. This requires four days, in ordinary instances, one egg being deposited daily. Incubation then succeeds, and lasts for eleven days. Here the female displays her true motherly instinct. She enters the nest, and with unwearied perseverance continues thereon, save during brief intervals of absence in quest of food, until she has achieved her heart's desire. The male is said to relieve her, but if such is the case, we have never been a witness of the fact. But while keeping aloof from such fatiguing duty, he is nevertheless a very faithful and devoted father when the young have quit their narrow prison-houses and welcomed the light of a new life. He is now as solicitous for their safety and well-being as the mother, and in case of molestation, unites his cries with hers to frighten away the intruder, or to cause him to desist from any assault he may have in contemplation. When twelve days old the little Swifts are able to climb to the summit of the chimney and receive their food. This always occurs a few days before their wings are sufficiently developed for flight. Even while quite young, in case of accident to the nest, they are able to make their way to the top of the chimney. In some cases they are carried beyond the reach or notice of their parents. When such occur they stubbornly refuse, human assistance, although uttering the most pitiful cries of hunger. When placed upon the roof contiguous to their native chimney, Dr. Brewer has known them to descend to its base, and there receive parental attention. In a fortnight they leave the nest, and are able to care for themselves. As this species is double-brooded in Pennsylvania the young are necessarily forced to self-maintenance at an early age, the thoughts of the parents being engrossed with preparations for a second family. These arrangements are perfected about the middle of June. In New England, and further north, but one brood is raised.

Like the old birds, the young are crepuscular rather than nocturnal in their habits, preferring to hunt for their prey early in the morning and late in the afternoon, or during cloudy weather. At times these predatory excursions occur at noonday in the broad glare of a full-orbed sun. The period for hunting is apparently regulated by the abundance or scarcity of appropriate insects. The adult birds, when with young, have often been known to protract their search for food long after night-fall. Caterpillars, diptera, beetles and lepidoptera of various kinds, constitute their menu, vast numbers of injurious, as well as beneficial species, being destroyed. Mature insects are chiefly in demand, which the birds, from being constantly on the wing, procure without much difficulty. Their flight then is varied and difficult of description. It consists of rapid sailing, and divers turnings, with occasional quickly repeated strokes of the wings. They never rest except in their roosting-places, to the walls of which they cling with great tenacity, being partially supported by their rigid tails. When tired of flight, they seek their homes, which they enter by falling headforemost, without any apparent concern. Their only note in these gastronomic explorations is a simple chip, uttered with considerable force, and at times so quickly, as to give rise to a confused twittering.

In the days of Wilson these birds were known, in the more unsettled parts of the country, to repose in large hollow trees, which were open at the top. Swallow Trees, as these roosting-places were commonly designated by country people, were fancifully supposed to be the winter-quarters of the Swifts, where, in vast heaps, they slept away the winter in a condition of torpidity, and whence, on the return of spring, they came forth to enliven us with their animated expressions. But in the present enlightened age, the intelligent take no stock in these statements, but consign such rubbish to the domain of oblivion. With the ignorant and superstitious it is different. They are invested with peculiar charms, which make them matters of pleasant reflection. Attempts have recently been made to revive these beliefs, but with slim chances of success. An instance may occur where some hapless individual has been left behind by his companions, and been forced to seek protection from the inclemency of the season in the cavities of trees, as the result of a sad emergency, which the vivid imagination of some visionary person might magnify into a hundred birds, but of such a case, we have no authentic knowledge.

For the benefit of those of our readers who have never examined these birds closely, but only while in flight, we shall mention a few of the characters by which they are readily distinguished by the real student of Nature. The same description will apply to the female as to the male, as her resemblance in plumage is so strong as to baffle the critical eye of the systematist to point out any well-marked distinctions. Both birds have a sooty-brown dress, which, however, is not uniform. The throat, from the breast to the bill, is considerably lighter than the general color, the rump a trifle paler, while above there is a slight greenish cast. Their length is five and a quarter inches, wing five and one-tenth, and tail two and three-twentieths.

The eggs of these birds are somewhat elliptical, rather less obtuse at one extremity than the other. Their ground is a pure, unspotted white, and in dimensions they vary but little. The average measurement from five localities is .77 by .52 inches.

Plate XXXIX. – OXYECHUS VOCIFERUS, (Linn.) Reich. – Killdeer

The above species is one of the most abundant, the most widely distributed, as well as the best known of all our Plovers. It is a denizen of the whole of temperate North America, where suitable localities abound, and, unlike the most of its kin, breeds pretty generally in the United States. Throughout the Missouri region, and even as far west as Salt Lake, Utah, it has been observed by parties connected with the different exploring expeditions of the National Government. It is found in the West Indies, and in the fall extends its migrations into Central and South America, where it passes the winter. These journeys are chiefly performed at night, not quietly, however, but with considerable clamor. In the time of Wilson it never entirely deserted the United States during the season of snow and ice, but retired to the seashore, where it managed to eke out an existence. No sooner had the rivers been released from their icy fetters than their shrill cries would be heard as they wended their way high overhead, or nestled among the partially submerged meadows that lined their banks. This was mainly the case in the South Atlantic States, where, amid the rice-fields they were to be seen in February and March.

With the return of mild weather our Southern friends, having their ranks possibly swollen by fresh accessions from sunnier climes, diffuse themselves over the higher latitudes. While some remain in the vicinity of the sea, and establish their homes in dry, sandy fields, the majority, as though tired of its wearisome monotone, strike for the interior, and lay claim to a piece of newly ploughed ground, or to some low stretch of laud, devoid of vegetation, and covered with shallow pools. Their arrival in the old haunts generally dates from the twentieth of April to about the middle of May, and is quite true to time in any given locality. For a short time subsequent thereto the sexes are concerned with the procurement of food, and may be observed wading knee-deep in the water of gravelly brooks and sandy streams for aquatic insects which contribute largely to their maintenance. While fond of such pursuits, the inclination to bathe within the limpid element to which they resort, is one which they cannot very well resist, for these ablutions are of frequent daily occurrence, and are enjoyed with great satisfaction. When disengaged from such occupations, they squat upon the ground, or stand erect upon both legs. If disturbed they seek to escape by running, or by vigorous application of the wings. Their alarm, on these occasions, is best shown by the peculiar cries of killdeer, kildeer which they emit. These expressions are sometimes varied to te te de dit, or simply te dit.

When the sexes have grown weary of surfeiting, they seem to come together by common consent, and, without much pomp or show, enter into marital relations. The union thus formed is one of purest devotion, based upon mutual sympathy and affection. Jealous of his spouse, the male throws around her his aegis of protection, and stands ready to wreak vengeance upon any of his feathered brethren who should dare intrude upon her presence, or offer her the slightest insult. While thus regardful of her honor, he is none the less thoughtful of her comfort and wants, and seems ever ready to obey her slightest mandates, whether expressed by word or gesture. When she is ready to nestle, he accompanies her in her explorations, and assists in the selection of a site for a home. This business is seldom delayed later than the middle of May, and, although of immense moment, is protracted but for a brief period. The spot chosen for a nest is a barren field by the seaside, a piece of ploughed ground, or some pool-ridden, grass-lacking plain in the interior. The nest is usually a slight hollow, and is lined with bits of grass, straw, sea-weed, pebbles, or such other substances as may be convenient to the builders. In some cases the birds evidently go to considerable trouble, and manifest a taste for the beautiful. A case in point is given by Wilson. In one of his travels he came across a nest that was literally paved with oyster and clam shells, and which, in addition, was neatly surrounded by a wall of the same, closely and curiously arranged. These birds were doubtless possessed of higher mental capacities than are common to their tribe, or they would not have gone to so much pains to beautify and improve their domicile. Again, nests are often found which do not show the least vestige of a lining. Scarcity of materials, or absolute lack thereof, might be offered as an explanation of the circumstance, but we have observed such apparently incomplete abodes in situations where there could have been no difficulty in procuring the necessary articles. Such-a simple affair, as the nest ordinarily is, cannot certainly occupy the builders for any great length of time. Consequently, we find that the female is ready to commence laying on the day succeeding the establishment of her home. Her complement of eggs being but four, usually at the expiration of the fourth day, she is prepared to incubate. Like most birds that lay their eggs in similar situations, the heated sand or pebbles have much to do with the hatching-process. This is presumably the case in fair weather. On cloudy days, during stormy weather, and at nights, it is necessary that they should be covered. Upon the female devolves this duty, and right cheerfully does she assume it. The time required to hatch the eggs depends upon various circumstances, such as seasonal warmth, condition of weather, and devotion of the sitting-bird. At any rate, in about sixteen days from the time of the deposit of the last egg, the young birds are ready to appear. Their deliverance is hailed with joy. Nothing can exceed the attachment of the parents to their charges. Let the nest be approached by a person, and the birds resort to various expedients to draw him away from the spot, or to infuse a feeling of fear into his bosom. They beat the air above his head with swiftly-plying pinions, or run along the ground with counterfeited lameness, uttering incessantly and loudly their shrill, but unmistakable call-notes. These movements are kept up for a long time, until the enemy is led over considerable scope of country, and the young are safe in places of concealment. The latter are fed upon insects of various kinds which the birds obtain in places they visit. Besides those which inhabit water, grasshoppers, crickets, beetles, worms, etc., form a large percentage of their food. Being somewhat crepuscular in habit, not many of the insects which affect twilight escape their close scrutiny.

The young are soon able to take care of themselves, but instead of deserting the family-circle when arrived at the age of responsibility in bird-life, they continue to frequent the same haunts with their parents, and, at the close of summer, descend with them to the seashore (thus constituting the small flocks which we then observe), or retire with them beyond our borders, to try their fortunes in brighter and more prolific regions. Whether they attain the adult plumage in the autumn, or in the following spring, it is not in our power to say; but when the birds make their appearance during the latter season, it is difficult to distinguish the young from their older brethren. By referring to the picture a strong similarity will be found to exist between the sexes. The rump and upper tail-coverts are of an orange-brown color; the tail feathers are white at base and tip, with a suffusion of orange-brown for a portion of their length, and marked with from one to three black bars. The secondary wing-feathers are mostly white, while the primaries have simply a white space. There is a black band across the forehead, and two broader ones on the neck and breast. The bill is black, and the feet pale grayish-blue. The length is about ten inches, wing six, and tail three and one-half.

The eggs are pyriform in shape, somewhat elongated, creamy-buff in ground, and marked with numerous speckles, blotches and scratches of a dark-brown color, which are larger and more generally distributed around the greater end, although abundant over the entire surface. The actual measurements of a set before us are as follows: 1.53 by 1.05, 1.50 by 1.06, 1.45 by 1.04, and 1.43 by 1.09 inches, giving an average size of 1.48 by 1.06 to an egg. The species is single-brooded.