Kitabı oku: «Nests and Eggs of Birds of The United States», sayfa 2

Plate III. – MIMUS. CAROLINENSIS, Gray. – Cat-Bird

The Cat-Bird is one of the most common and conspicuous of all our feathered visitants. It reaches the United States from its Central American home, on or about the 10th of April, and thence diffuses itself over the whole country, northward as far as the Saskatchewan, and westward to the Rocky Mountains.

Immediately upon its arrival, it seeks the shelter of dense woods, or the security of waste fields and bramble-ridden hedges. In such situations, among the dead leaves that lie scattered upon the ground, it gleans a well-earned subsistence. But later, when the leaves begin to appear, and with them an abundance of insect-life, these retreats are deserted by a few venturesome individuals, and an abiding-place is sought amid the quiet scenes of rural gardens.

A week or ten days, however, elapse before the sexes are ready to assume conjugal relations. Being vigorous feeders, and living in the midst of plenty,' they are seemingly all unconscious of the better and nobler instincts of their being. But feeding eventually satisfies appetite, and conduces to the awakening of the amatory forces from their hitherto dormant condition. The males, by their altered demeanor, are the first to show signs of change. We no longer observe them engaged in the pursuit of the juicy caterpillar, or the gilded butterfly, with the same energy and zest as before. Their aims are higher, their aspirations loftier. Perched upon a small tree, or screened from observation by dense clumps of bushes, with heads bent skyward, they startle the echoes of woodland and valley with their strange, ecstatic music. But the females still continue feeding, as though utterly oblivious of the concert which is intended for their benefit. After a day or two thus spent, they become less absorbed in such matters, yield to the potency of song, and coyly emerge from obscurity to welcome and encourage their would-be suitors. The period of courtship is short, and unattended by any of those peculiar antics which characterize many species at this time.

In the Middle and Western States mating occasionally commences as early as the 25th of April, when the season is remarkably forward, but generally about the first of May – seldom later. In the Territories, from some unknown cause, it is delayed to a later period. Very little time is wasted after this event has occurred, in celebrating the occasion, for the pair soon begin to look for a proper nesting-place. This is a labor not entered into without previous care and deliberation. Ordinarily a week or ten days are spent in making a choice of locality. The site selected is usually a brier, cedar, thorn-apple, or a bush in the midst of a grove or hedge, seldom remote from a settlement. The nest is sometimes placed in a maple, and when such is the case, the birds take the precaution to build it pretty well up. During the summer of 1880, my son discovered one in a crotch of the red maple, at an elevation of thirty feet from the ground. This, however, is exceptional, as the height usually ranges from three to about twelve feet. It sometimes happens that an injudicious selection of locality has been made, and a nest has been nearly completed before the mistake is discovered. In this predicament, instead of "making the best of a bad bargain," the birds ignore the site for another better suited to their purposes. The situation being finally decided upon, both birds work diligently during the cooler hours of the morning and evening, for five or six days, in the construction of their home. In some instances, particularly during moonlit nights, the work has been carried on long after twilight has faded from the earth. Unlike the case of the Cedar-Bird, which we have already cited, there does not seem to be any regular division of labor. Both birds collect the materials, as well as arrange them in the nest. When a suitable article has been found, the finder does not fly immediately to the nest and adjust the piece, but indulges in short flights from one object to an adjoining one, carefully surveying the premises all the while, until within a few yards of the nest, when she rapidly flies thither, and having disposed of her burden, goes off in quest of others. Where accustomed to man, the Cat-Bird does not seem to be much annoyed by his presence.

Nidification ordinarily commences about the 18th of May. The nest is placed in various positions – sometimes 011 a horizontal limb, occasionally in a crotch, but generally among the branches of the bush upon which it reposes. The materials of composition are as varied as they are numerous. In thickets, and also in places removed from human habitations, a platform of dried leaves, slender sticks, or weeds is used as a basis, on which is reared a superstructure of small twigs, fine roots, herbaceous plants, bits of straws, pine needles, and other materials which are common to such situations. But when a nest is built in close proximity to the home of man, bits of string, strands of silk or thread, and bunches of cotton or wool are appropriated, and made to do excellent service.

From the foregoing remarks it is obvious that nests vary according to changes in the environment. Hence, what is typical in one locality might be deemed but a deviation from the normal form, when compared with a nest of the same species found in an entirely different neighborhood, and vice versa. Mr. Ingersoll describes a nest found near Norwich, Connecticut, which was suspended between two small bushes in such a manner that it had no other support than that afforded by a slender spray from each bush; but the large mass of crooked sticks below offered so many hooked ends and projections that the nest was very secure. The writer describes elsewhere a nest that was carelessly made, and bearing a close resemblance to the structure of the Maryland Yellow-throat, which he supposed to be the work of young or indolent birds. Another, on the contrary, showed superior workmanship. The outside of this cosy and beautiful nest was composed of wool, raw cotton, strings, fragments of lamp-wick, a slight intermixture of tangled silk, fragments of lichens, etc., held in situ by strands of silk. Upon this basis was built a superstructure of fine rootlets, intermingled with patches of wool.

The nest which we have figured in the Plate was found in the vicinity of Philadelphia, Pa., in the summer of 1876. It is represented the usual size, and shown in its natural position upon a cluster of blackberry branches. Exteriorly, it is formed of wrapping string, bits of thread, fine roots, cotton ravelings, a few grayish lichens, and bunches of discolored raw cotton in great quantities. Interiorly, there is a lining of slender grass stems, which monotony is relieved in a measure by a piece of lamp-wick. The external diameter is five inches, and the height about two and a half. The cavity is three and a half inches, and the depth an inch and a half.

Such facts as are detailed above, with innumerable others of a similar nature that might be adduced, most abundantly and conclusively prove that birds are not the dull, senseless, routine-loving creatures which those who have some pre-conceived opinion to uphold, or cherished theory to sustain, are wont to argue. Though many of their actions are purely instinctive or mechanical, yet evidence is not wanting to show that they are gifted with a faculty similar in character to that possessed by man, but differing in degree. A thousand circumstances justify the belief that they often reason a priori from cause to consequences, providently managing with a constant aim for future comfort, convenience and necessity. Instinct is always the same thing, never advancing, never retrograding. Reason tends to improvement, always seeking a higher plane of existence. To say that changes in nest-building imply a change of instinct, is to perplex the understanding by a perversion of language; but to ascribe them to the operations of reason, influenced by motives, seems to be the most rational view to take of the matter.

The nest being completed, which is usually the case in about five days from the time of starting, a brief season elapses before any eggs are laid. In the Northern States this happens about the third week of May, and then only one is deposited each day, for four or five days. The necessary complement being laid, the female immediately takes the nest, and incubation follows. This is her exclusive task for a period of twelve or thirteen days. While she is thus engaged, the male stations himself close-by the nest, only departing therefrom in quest of food for himself and partner. Should an enemy approach, he assails the intruder with commendable fearlessness and boldness. Various snakes, particularly the black-snake, are their inveterate foes. When an attack is made by one of these wily creatures, both parents, heedless of danger, often fly so close to the assailant as to lose their lives in efforts to prevent the nest being ravished and despoiled. But in the case of human depredators, knowing that resistance would be futile, they seek to deter them from any contemplated sacrilege by the most discordant cries and frantic gestures.

The young are objects of tenderest solicitude. Both parents vie with each other in rendering them every needed service. While one is absent from home in search of food for their rapacious appetites, the other is guarding the nest and its precious charges with the most jealous care. Earthworms, spiders, flies, caterpillars of non-irritating properties, together with such berries as the season affords, are collected in vast quantities, and fed to these helpless creatures. But as they increase in size and age, other articles are added to their voluminous bill of fare. In about twelve days from the time of hatching, the young are able to quit the nest, and in six days more, are ready to be initiated into the mysteries of flight. This important duty devolves exclusively upon the male parent.

The eggs are oval in form, of a dark emerald green color, very highly polished, and measure .97 of an inch in length, and .68 in width. There is small chance of confounding this with any other American bird's eggs – certainly after a specimen has been once seen. Dr. Abbott, as quoted by Ernest Ingersoll, once discovered a nest, at Trenton, N. J., that contained purely white eggs, which hatched in due time into perfect young. Similar instances are known in the case of other species laying dark eggs, where one or two white examples have been found among others of the normal color in the same nest-complement. But a single brood is positively known to be raised, although cases have come under our observation of nests with fresh eggs as late as the 15th of August – possibly the work of birds whose early efforts had been frustrated by enemies, or by some accident.

Plate IV. – ICTERUS SPURIUS, Bonaparte. – Orchard Oriole

The Orchard Oriole is quite abundant throughout most of the United States, from the Atlantic to the Missouri Valley, and on the southwest to the valley of the Rio Grande. Individuals have been met with by Mr. J. A. Allen as far west as the base of the Rocky Mountains, in Colorado, the extreme limit of its western range. It is probable that it breeds throughout the entire area of its distribution – sparingly, however, in New England, according to eminent authority; but quite freely in the Central States, from New York to South Carolina, and thence south-west to Texas.

The period of its arrival in the United States from the genial clime of Guatemala, where it winters, has been fixed by Mr. Dresser, who has carefully studied its nesting-habits in Texas, as early as the first or second week of April. But, farther north, its presence is not observed before the last week of April, or the beginning of May.

Unlike the Warblers and Thrushes, which prefer secluded localities, the subject of our sketch delights in cultivated grounds, particularly where the apple and the pear abound. Here it takes up its quarters, accomplishes the object of its mission, and thence retires to its distant winter-home. Occasionally, a few individuals are to be found in waste grounds, dense thickets, or along the borders of woods, but such cases are exceptional, and conditioned only by the close proximity of some time-honored orchard.

Mating does not occur until the 10th of May, more than two weeks after the advent of the sexes. But from the first, the male, who precedes his partner by some two or three days, may be heard in the early morning, and quite as frequently at the close of the day, from the tall tree-tops, chanting his wanton rhapsodies, for a half-hour at a time, utterly unmindful of passers-by. His roundelay, which is undoubtedly the free and happy expression of a heart actuated by the generous impulses of love, though composed of rather shrill and sprightly notes, and uttered with considerable agitation, is quite as pleasing as that of his nearest kin, the Baltimore Oriole. Clear, distinct and resonant, it thrills the air around, and is at last borne to the ears of some lonely female, tired with travel, and unblest by a partner. The life of the Orchard Oriole seems to be one of joyous song. Although, fond of a dainty tid-bit, in the form of a juicy worm, he is not given to gormandizing; he only eats from sheer necessity; for, after having satisfied the demands of Nature, he resumes his soul-stirring strains, to the delight of man and bird.

The sexes having come together in a wise and business-like way, with little or none of the bluster that is customary on such occasions, a conference ensues, which results in a temporary separation for mutual good; one bird going in one direction, and the other in an entirely opposite course. The selection of a suitable spot for a home is the vera causa of this divergence. This is evidently a labor of little moment, as, ordinarily, but a day or two is thus spent. It must not be inferred, however, that the birds are not particular as to place. A large experience has convinced us that great care and deliberation are then exercised. Many a tree is visited, and often the same tree again and again, before a decision is reached; and when at last a suitable site has been chosen, the happy pair set to work with praiseworthy diligence to construct a home.

As previously remarked, an apple- or a pear-tree is generally chosen for nesting purposes. This is especially the case, as far as we are able to ascertain, in the Central and Western States; but in Texas, the nest is suspended from the upper branches of a mesquite-tree. In the North, the common red maple, and several species of coniferous trees, are occasionally chosen, from some peculiar advantages which they possess. A nest in the writer's collection, which was built in the summit of a common swamp maple, occupies a very anomalous position. It is placed within a crotch formed by four nearly upright, slightly divergent branches, and is secured by long, flexible grasses from the nest, wrapped tightly around the twigs. Another specimen, from Germantown, Pa., is made to dangle from the end of a pine-branch. A peculiarity about the latter nest is the strained position which the four branches to which it is fastened are made to assume. The main twig, which is also the thickest (being about three-fourths of an inch in diameter) shows evidence of having been forced from a horizontal position to one that is almost vertical. The latter is really the best authenticated case we have seen of the truly pensile style of nest. In most instances these structures are but partially suspended, being supported from beneath by projecting branches.

In five or six days from the time of the assumption of matrimonial relations, the nest is started, and through the united efforts of both birds for the period of a week, is brought to completion. Although nidification usually commences about the 20th of May, from some inexplicable cause or other, this essential business is often deferred until the middle of June and, occasionally, as late as the beginning of August. But in the latter case, the birds are undoubtedly prevented by varions accidents from carrying out their designs earlier in the season. In the building of a home, either the male collects the materials, and the female weaves them into a nest, or the converse is the case.

There is little variety noticeable in the materials that compose the nest. The generality of domiciles which we have seen from Texas, Georgia, Florida, New Jersey, Pennsylvania, and several of the Western States, have no lining, but are entirely constituted of one substance – a flexible kind of grass or reed. In a few cases we have discovered a slight lining of vegetable wool, doubtless plucked from the young and developing fronds of various species of ferns. Bits of yarn, down of seeds, and animal wool, have been mentioned by various observers as occasional linings.

Such is the homogeneity of its texture, that once seen and recognized, it can never be forgotten or confounded. A nest from Texas is the exact counterpart of a similar structure from Pennsylvania, or of one from Michigan. The abundance of the particular species of grass out of which these birds construct their homes, and the facility with which it is obtainable in localities remote from each other, conspire to produce the resemblances which are found to exist.

Plate IV exhibits a nest of this species which was obtained in the vicinity of Germantown, Pa., during the summer of 1880. It was suspended from the branches of a pear-tree, in the manner shown in the drawing, at an elevation of forty feet from the ground. It is built exteriorly of a peculiar kind of long, tough and flexible grass, which is common in Pennsylvania. The material is woven through and through in a very wonderful manner, and with as much neatness and intricacy as if actually done by a needle. It is hemispherical in shape, and open at the top. The external diameter is four inches, and height two and a half inches; the cavity is two and a half inches wide, and two and three-quarters in depth. The color of the outside is yellow, while that of the inside is a deep brownish-red.

Another specimen which the writer possesses from the same locality, is built of the same material, more highly colored interiorly, but less so exteriorly. It is pouch-shaped, and measures two and a half inches in internal diameter, and four and a half inches in depth. The length is five inches, and the external diameter three inches. When in position, this nest was so placed that the short spurs of the pear upon which it was built, with their beautiful green wreaths of leaves, met and roofed it over, thus constituting a natural covering for the protection of the young during the prevalence of inclement weather.

Dr. Brewer describes a nest taken by Mr. Brandigee in Berlin, Conn. This structure was elaborately and skilfully woven of long green blades of grass, lined on the inside with bits of yarn, animal wool, and a woolly substance of purely vegetable origin. In external diameter and height it measured four inches; in depth, three inches, and in internal diameter three and a half inches – being widest in the middle. Specimens, similarly colored, have been frequently observed in Pennsylvania.

By far the most remarkable structure which we have seen is the one we are about to describe. This domicile was built in a red or swamp maple, at an elevation of nearly thirty feet from the ground. It is a double nest, composed entirely of long, flexible, yellow grasses, and securely fastened between three nearly vertical branches, in a linear direction. The main nest is inversely sub-conical, four inches high, with an external diameter of three and a half inches in the middle, and four at the top. The diameter of the cavity is three inches, and the depth two and three-fourths inches. The smaller is joined to the first by a continuation of the grasses of the latter, is somewhat similarly shaped, but less compact in structure. The height is one and three-fourths inches, external diameter in the long direction three and one-fourth inches, and in the short, but two inches. The depth of the cavity is one and three-fourths inches, and the width, one and a half inches. In one side there is a circular hole one inch in diameter. Various opinions have been ventured as to the object of this additional structure. Some have contended that it was never intended for occupancy or ornament, but is simply a fabric which the authors have failed to complete. But its completeness and finish operate against such a theory. The writer, as well as others who have witnessed this curious specimen of mechanism, are convinced that it was erected for a special purpose – namely, the accommodation of either parent while the other is sitting. The opening alluded to, served for the head of the nonsitting bird, who, from his position, looking away from the main building, could detect the approach of enemies, like a sentry upon an outpost.

The nest being completed, on the following day the female begins to deposit her complement of three or four eggs, at the rate of one egg daily. Incubation now ensues, sometimes on the day of the last deposit, but generally on the morrow. This duty lasts from fourteen to fifteen days, and is wholly the work of the female. While she is thus occupied, the male stands guard over the nest, or acts the part of a dutiful and affectionate husband, by providing her with the necessary food. Should their home be disturbed by feathered assailants, or by man, the female leaves the nest, and by loud cries and menacing gestures, seeks, with the assistance of her partner, to drive off the intruders. Often the attack is carried on with a boldness and determination that challenge admiration.

The love for offspring is very intense, and manifests itself in unwearied devotion, and the tenderest solicitude. From early morn until dusk, one parent or the other is constantly on the go for appropriate articles of fare. Usually but one is absent at a time on this important business. But the demands for food are so pressing, that both are sometimes compelled to leave home, but only for a short time, and then never beyond seeing distance of the nest. At first the young are fed upon smooth caterpillars, aphides, spiders, ants, butterflies, and dipterous insects; but as they mature, small beetles and other hard-shelled articulates are added to their varied and extensive menu. At the age of fifteen days, they quit the nest, receive instructions in ærial navigation under the tutorage of the paternal head, and in ten days more, are prepared to shift for themselves.

One peculiarity of this species must have struck the attention of every careful observer of its habits; that is, its remarkable sociability. Audubon cites a case where no less than nine pairs were found breeding in the same enclosure. We have known instances where as many as five nests, all occupied, were crowded in the same orchard, within a short distance of each other. The most perfect good feeling and harmony prevailed in this little colony, the birds mingling together with the freedom and ease of inhabitants of the best regulated human communities.

The eggs are oblong-oval in form, pointed at one extremity, and marked with pale purple blotches and a few deep dark purplish-brown dashes upon a light bluish-white background. Specimens from Washington measure .85 by .62 of an inch; from New Mexico,79 by .54; and from Pennsylvania,88 by .58.