Plate XXVI.—POLIOPTILA CÆRULEA, (Linn.) Sclater.—Blue-gray Gnatcatcher.
When the first breath of spring, on zephyr wings, blows over the South, laden with dewy moisture and balm from regions beyond the Gulf, this tiny speck of bird-life feels the glowing influence, and hails it with delight. Weary and restless, it seeks to break away from its winter-home, or change the monotony of its existence. While some are inclined to newness of climate, and leisurely wend their way northward, others are happy and contented where they are. Those, imbued with a spirit of migration, quit their less ambitious neighbors in March or April, to spend their summers abroad. All reach their destination by three great routes. Those on the east, that winter in the isles to the southward, follow the trend of the great Atlantic slope as far north as the valley of the Connecticut and kindred latitudes. Others, doubtless, from our southernmost States and the Mexican possessions, pursue a central direction, one part passing through the eastern half of the Mississippi Valley to the Lake country, and the other ceasing from their toilsome journey when the northern frontiers of Nebraska and Iowa are attained. While the western wave, so to speak, collect from their winter-retreats in the valleys of the Colorado and Rio Grande Rivers and follow these streams to their headwaters, or turn aside from their course and make their way through the fertile slopes of the Pacific to the latitude of 42 degrees.
Though an early migrant, yet, by reason of the tardiness of its movements, this species does not arrive in the Middle States until the last of April, or the beginning of May. In Maryland and Virginia, according to Coues, its advent occurs during the early part of April. The Carolinas, Northern Alabama and Tennessee witness its appearance about the fifteenth of March when the season is not retarded by a long, cold winter, and the Northern Central States, towards the close of the ensuing month, which, by some inexplicable cause, seems also to be the date of its coming in the great Colorado Basin.
Appearing at a time when the trees are beginning to clothe themselves in shimmering robes of green, and often before the oaks and hickories have burst their tumid buds into the rich drapery of foliage which is to cover their unsightly nakedness, our little friend is none the less welcome. From the tall tree-tops we are first made aware of his presence by the shrill, wiry notes with which he salutes the morn, and which he is accustomed to utter during the livelong day as he moves in and out among the branches in tireless pursuit of prey. Not a tree-crevice escapes his keen scrutiny. While thus eagerly prying into every cranny or crack that meets his gaze in quest of the lurking culprit, should the buzz of a fly or the hum of a beetle be borne to his hearing, in an instant he is off with a dash that is wonderful to behold, and the unhappy insect is made to repent the folly and temerity of its action. At such times, his behavior seems to be all hurry and bustle, as though the work of a life must be crowded into a few short days.
We have but pictured to the minds of our readers the selfish side of his character, as manifested in the uncontrollable rapacity which sways him. But when the finer and more ennobling impulses of his nature, stimulated by returning warmth, have once more gained the mastery, a milder grace attends his every movement, and sweeter accents attune his voice. We no longer hear those peculiar sounds, which to the human ear resemble tsee-tsee-tsee, repeated in rapid succession, and which, a few short weeks before, were everywhere to be heard—a fit accompaniment to his reckless life—but instead, are regaled with the sweetest, tenderest music. This is so low, that to appreciate its effect, the auditor must be but a few yards distant from the tree which our modest vocalist has selected to be the scene of his endeavors. So well sustained is the effort, and, above all, so faultlessly rendered, that the most austere critic could hardly fail to assign the performer a high place among the feathered choir.
Like many of his kith, he does not seek the bare branch of some tall tree, where he can be seen, and thrill the air of vale and wood around with ear-splitting utterances. He despises such notoriety. Hid away in the leafy canopy that wreathes the brow of some gnarled oak, he loves to take his stand, and there pour out his soul in all the ecstasy of subdued song. Unpretentious as his music may be, and undervalued for its lack of force by the vast choir of singers around, yet it has a depth of power and feeling, which, as it is borne aloft upon the bosom of the gentle air, strikes the ears of some timid, modest creature, and startles the slumbering chords of her being into harmony. Life to her now acquires new vitality and enjoyment. With heart beating high with rapturous emotions, and urged by an irresistible desire, she betakes herself on swiftest pinions to the spot whence emanate the sounds. As she nears it, the music comes to her with fuller distinctness, and sends the heart-throbs following one another in happy, swift succession. The singer does not abate his efforts, but keeps them up with scarce an intermission, until they elicit a response, or the gentle, loving one is wafted to his immediate presence. On the reception of a reply, his movements are restless and animated. But let the object of his thoughts but flit before his excited vision, and in a moment he is by her side. In a variety of actions which, from a human standpoint, seem meaningless and frivolous, he conveys to her his love, and the boundless appreciation of her worth. This done, he next attempts a song, which seems to soothe her hitherto agitated feelings, and awakens confidence and resignation. He is not slow in perceiving the advantage thus acquired, and, consequently, follows it up with other advances, which completely place her at the disposal of his mercy and power. Conquered at last, she yields herself a willing subject to the potency of love, and becomes his wedded wife.
The selection of a home-spot now claims the attention. High, open woods are preferred for this purpose, although trees along the borders of streams, and in low, damp situations, are sometimes chosen. There seems to be no particular fancy for one tree more than another, provided it be lichen-clad. Those whose branches are thus ornamented, the oak especially, will be found to be more frequently favored. Instances are known, however, of nests being placed upon the maple, a tree remarkable for its dearth of such vegetation. Having chosen the site, the erection of a dwelling is next in order. Accordingly, the pair set about this business.
The time chosen for the work is generally the month of May, when insect-life runs riot, and mother earth is ablaze with a thousand floral beauties, the free-will offering of the queen that now presides. From its dawn to its close, these curious structures may be seen in various stages of completion, with eggs and without, tenantless and occupied. Specimens from Texas, with egg-complements, have been found on or near the fifteenth, which had doubtless been commenced two weeks before. Others from New Jersey and Pennsylvania contained incubated eggs as late as the twenty-eighth, while one from Eastern Tennessee with two fresh eggs was found on the sixth of the month following. But this may have been a case where the early efforts of the birds to nest had been prevented by circumstances beyond their control. Reports from the extreme northern and western limits of the range of these birds point to the same conclusion.
The height which these nests occupy above the ground varies with the locality. In some places they seldom attain a greater elevation than ten feet, but, in the majority of cases, this limit is exceeded, and the heights of fifty, and even sixty feet, are reached. There is less variation in form noticeable, their shape being generally that of a truncated cone. One nest before us from the South differs somewhat from this figure, and may be pronounced as inversely conical. The position, too, is quite uniform. Most of them are placed among slender branches, to which they are woven by the ingenuity of the architects, and, although non-pensile, are the sport of every breeze. But so securely are they fastened, that to dislodge them from their moorings, is a matter of no little difficulty.