Читать книгу Nests and Eggs of Birds of The United States - Gentry Thomas George - Страница 13

The Chipping Sparrow, so familiar to everybody, is not only one of the most abundant, but also one of the most widely diffused of all our species. It is found from the Atlantic to the Pacific in its two races, and breeds from Georgia to Nova Scotia on our eastern seaboard, and from Vera Cruz, Mexico, northward through Arizona, Utah and California. Although obtained at different seasons of the year in all portions of North America to Mexico, it is a strange and remarkable fact that its breeding-grounds are not equally extensive.

Large numbers of these birds annually winter in the valley of the Colorado, and thence doubtless spread themselves over the whole Pacific region, as far north as Fort Resolution, on Great Slave Lake. In the East they may be seen in companies of a hundred or more from October to April through Northern Georgia and South Carolina, and possibly in the Gulf States.

On the return of mild weather, which generally follows the vernal equinox, these flocks forsake in a measure their winter homes, and journey northward. Those from Northern Mexico pursue a northwesterly course, reaching Arizona about the twenty-fourth of March, where a part remain to breed; but the greater portion pass up the valley of the Colorado, and after receiving fresh accessions to their number, continue their migratory course until they have reached their destination. On the other hand, our Eastern variety tarries longer in the South, and only takes its departure when Nature, awakened from her winter sleep in our Northern States, has begun to put on her charming robe of green. But unlike its Western brother, it arrives in pairs, and never with the show and pomp of a large army. The tardiness of vegetation, and the paucity of insect life incident thereto, have doubtless much to do with the time and manner of its coming. In the Middle States this event happens during the last week of April, and in New England about the fifteenth, but the birds do not seem to become very abundant in the latter section until the beginning of May.

The Field and Song Sparrows, near relatives, are much earlier comers, and are already in full song, making the groves and fields vocal with praises, long before the Chippy has made his appearance. But when the latter does arrive, we must look for his presence in our gardens and orchards, rather than along the borders of thickets, where he commends himself to our favor and esteem by his tameness and sociability. About our doorsides he loves to glean his fare, and when an opportunity offers, will often enter our houses during meal-times. So accustomed to man does the species become, that individuals have been known to present themselves regularly for food, as often as thrice a day, and even to accept the same from human hands.

The male is so absorbed in feeding during the first ten days of his stay that no attempt at singing is made. His only note then is a simple chip, indicative of unrest. This is slowly uttered, and at somewhat measured intervals. But later, he essays a song, and throughout the month of roses, his unpretending ditty, which consists of a repetition of the same sound, is kept up for hours together with scarce an intermission. Though poor his reputation as a singer, yet individuals have actually been known to sing, and very sweetly, too, but such cases are wholly exceptional, et lusus naturae. Mr. Flagg, in speaking of the male, says, "He seems to be the sentinel whom Nature has appointed to watch for the first glimmerings of dawn, which he always faithfully announces before any other bird is awake. Two or three strains from his octave pipe are the signal for a general awaking of the birds, and one by one they join the song, until the whole air resounds with an harmonious medley of voices." Again, says the same happy writer, "His continued trilling note is to the warbling band of morning musicians which may be heard before sunrise during May and June like the octave flute as heard in a grand concert of artificial instruments."

The singing of the males is the inauguration of a new era in bird-life. The search for food no longer engrosses the attention as of yore, but the all-absorbing passion of love. The sexes cease their solitary wanderings. The females, moved by the touching appeals of the males, leave their native haunts, and join their masculine companions. All is now a scene of bustle and activity. The wooer and the wooed meet and lavish upon each other the most endearing attentions. Happiness reigns supreme. But the acme of felicity has not yet been reached. This is brought about by degrees, and is only perfectly attained when conjugal relationship is assumed.

In some parts of the country this important business is entered into as early as the fifteenth of May, but in others it is necessarily deferred until the succeeding month. The event is unattended by any peculiar demonstrations of joy, and is mostly celebrated in a matter-of-fact, businesslike way; the happy couple proceeding at once to an exploration of the surrounding scenery for a suitable place in which to build a home. This is a matter of little moment, as almost any small tree or low bush is available for the purpose. The nest is never placed on the ground, even in Arctic regions, where so many of our tree-builders vary from this custom to nidificate on the ground. In the vicinity of houses,' small trees, shrubbery and vines are utilized; but in pasture grounds, and on the borders of small thickets, the common red-cedar is chosen. Having selected a suitable site, both birds apply themselves to the task of building for a period of four or five days, when a neat and rather cosy structure is the result. Considerable variation is discernible in the architecture of different individuals. Some nests are rudely constructed, and rather loose and tenuous. Others have much of periphery, but little of thickness and internal depth.

A typical nest is hemispherical, neatly but loosely built, and possesses a cavity very symmetrical in contour. It is usually composed on the outside, except in rare cases, of fine rootlets, and is lined with black and white horse-hairs. In a beautiful domicile before us very few roots are noticeable, the bulk of the fabric being composed of horse-hairs, densely and compactly interwoven, and covered exteriorly with a few fine twigs and lint. Other nests before us are built entirely of fine rootlets. When such structures are found in bushes, and are well secured and protected by enveloping leaves and twigs, a curious anomaly often presents itself. A case of the kind came under our observation in August, 1876. Since that time others have been met with. It is where the nest, instead of occupying a nearly horizontal position, which is the natural one, is placed at an angle of inclination, and bears in the superior third a circular opening. What the object of this aperture can be, it is impossible to say, as the bird could never be surprised while on the nest. Possibly it was designed for the accommodation of the head of the owner while the process of incubation was going on; or, it may have been intended as a mode of ingress and egress, which opinion the position of the nest and its surroundings would seem to warrant.

One of the most curious and exceptional nests which we have ever seen, was obtained in the summer of 1870, in Northumberland Co., Pa. This nest was built upon a small bush, at an elevation of two feet above the ground. Externally, it is composed of dried plants, of an herbaceous character, with seed vessels intact. Internally, there is a slight lining of white horse-hairs. The diameter, on the outside, measures nearly four inches, and the thickness three and a half inches. The diameter of the cavity is three inches, and the depth nearly two. It is a magnificent structure, closely and compactly woven, and exactly hemispherical.

The drawing represents the usual style of nest. The position upon a branch of the red-cedar is one that is frequently chosen. The outside is mainly composed of fine roots of a reddish-brown color, and the inside of an equal mixture of white and black horse-hairs. The dimensions are as follows: External diameter, three inches; internal, two and a quarter inches; depth inside, three-fourths, and outside, one and an eighth inches.

The nest being finished, oviposition commences on the ensuing day, and proceeds at the rate of one egg daily, until the entire number is laid. This varies from three to five, even in the same locality. Incubation commences on the day after the last deposit has been made, and continues for a period of ten days. It is chiefly the duty of the female, although the male occasionally lends his assistance by taking the nest. When not thus occupied, he either polices the premises to guard against intrusion, or is away in search of food. When with young both birds become devoted parents, and evince the greatest anxiety and consternation when their nest is disturbed.

Their actions at such times bespeak fear rather than courage. We have never known them to assume the threatening attitude which characterizes so many of our small species, nor seek to drive intruders away by sharp scoldings and angry gesticulations. But knowing that resistance would be useless, they quietly submit to circumstances, and repair to other scenes where they think to be secure from molestation and harm in carrying out the chief object of their being.

The young are fed at first on various larvæ, especially those of a lepidopterous character. To these, earth-worms, aphides, beetles and flies are added as condition and age require. When twelve days old they are persuaded to leave the nest, and, under the direction of the paternal sire, receive instruction in bird-lore. A period of eight or nine days more, and they earn their own living. They do not forsake their parents, however, but follow them into their old hunting-grounds, and thus help to constitute the small flocks which are generally observed in the fall of the year in our Eastern and Middle States, previous to migration.

The eggs are oblong-oval in shape, and vary considerably in size. They are of a bluish-green color, and are sparingly spotted with umber and dark brown markings about the larger extremity. In some specimens, the latter are grouped after the fashion of a wreath, but this is the exception rather than the rule. The largest specimen we have ever seen measures .80 by .57 of an inch; the smallest,58 by .47. The average measurement is .72 of an inch in length, and .54 in breadth. The species as far as known is single-brooded.