Читать книгу Nests and Eggs of Birds of the United States - Thomas G. Gentry - Страница 14

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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.