A remarkable peculiarity of this species whilst feeding deserves a passing notice in this connection. We allude to its habit of opening and closing the wings, and of expanding the feathers of the tail. Whether these movements are done for show or not, we are unable to say. They cannot be considered as designed solely for attracting the sexes to each other, which would doubtless be the correct interpretation if they were practised only during the season of mating. But as they are to be noticed throughout the entire stay of these birds, and always while engaged in feeding, it seems to us that they are expressive of delight and satisfaction. The capture of an insect evokes them, and from being habitual, it is no more than natural to suppose that the sight of a loved one—the partner of former joys and sorrows—would produce feelings akin, but stronger, and lead to similar manifestations. Unlike what is customary among birds, the female Redstart rivals the male in powers of song.
Never gregarious, for three weeks and more from the time of arrival the sexes lead solitary lives, and spend the time in feeding. At first their foraging is confined to high, open woods, but as the days flit by, they become more friendly and visit orchards and lawns, or glean among the trees that line our roads and lanes. They now become quite tame, and may be approached with comparative ease. In the procurement of food they are as often found upon the upper branches of trees as upon the lower, and do not deem themselves too proud to come down to lower growths, or betake themselves to the ground. As the males are the first to show themselves, it is to be presumed that they are the earliest to migrate. They seem to be several days in advance of the females. But perhaps the latter are more modest and retired, and do not emerge from their sylvan quarters as soon as their lords, which would account for their apparent delay. But whether or not they arrive together, it is evident that they pay little regard to each other for a fortnight, and only care for selfish gratification.
This condition of things continues until the last of May or the beginning of June, when the males seek out their partners, and prepare for the work which has called them through many a weary league of country. From the time of mutual recognition until the construction of the nest, affairs progress with wonderful rapidity. The selection of a building-spot, as also does the labor of building, depends upon the female. She is rather whimsical, and, above all, hard to please. The male occasionally assists, but things often go wrong, and rather than provoke a tempest, he takes a position where he can inspect the work as it progresses under the critical eye, and by the skilful manipulations of his steady, industrious and persevering housewife. While for these long, weary days she is thus occupied with the structure, her partner sweetens the ennui of her life by an agreeable ditty and words of endearment. As if to show his appreciation of her exertions, he now and then rewards her with one of his choicest captures.
Dense woods with plenty of underbrush are generally chosen when nesting. Occasionally, through some freak of the builders, the domicile is placed contiguous to human habitations. Almost any small tree or bush answers for its support. A crotch receives the fabric and renders it secure from violent storms of wind. Upon first examination it seems to be the counterpart of the home of the Summer Yellow-Bird, but this impression is soon abandoned when a comparison is instituted. A typical structure before us, which was built upon a forked branch of the wild plum, at a height of ten feet from the ground, is composed of the fibres of the wild flax, with a few spiders' webs, on the outside, and is lined with a profusion of horse-hairs. In diameter it measures two and three-fourths inches, and three in height. The width of the cavity is two inches, and the depth one and five-eighths. The whole affair is beautifully hemispherical, and neatly and compactly woven.
In the construction of the nest there is visible a marked uniformity in character, although the materials vary with the localities. Shreds of savin-bark, bits of wool, strips of bark, thistle-down, bits of paper, and other fragments are sometimes utilized in the periphery, while vegetable fibres, pine leaves, dry grasses and wool of plants are made to do good service in adding a warm and comfortable lining. From what we read it seems that the Redstart does not always build directly upon a branch, but is occasionally prone to make use of the nest of some other species as a foundation. A case is cited by Dr. Breaver where the Redstarts had placed their nest upon a Blue-eyed Warbler's, which had either been deserted, or from which the rightful owners had been expelled. The base of this fabric was composed of brownish wool plucked from fern leaves, with a commingling of herbaceous stems and leaves. Within this wonderfully unique structure was placed an entirely distinct nest, firmly and elaborately interwoven of pine needles, stems of grasses and long, slender ribands of bark.
Oviposition is closely attendant upon nest-completion, and proceeds at the rate of one egg daily, until the entire set is laid. Incubation immediately follows, and is the exclusive duty of the female for eleven days. While this is going on, the male bird busies himself with the food-matters? and is a very thoughtful and attentive provider. When not employed in this business, he shows his regard and solicitude by remaining at home. In times of danger he never shirks his responsibility, but comes boldly to the front, and by his clamors and menacing gestures endeavors to frighten the intruder away. Bold and courageous he will often dart with wide-open jaws into the face of the person who dares to disturb his nest or mate. So strongly attached to her nest, on the other hand, is the ladybird, that she will permit a near approach thereto before abandoning it. In times of assault she is less demonstrative, and when her nest is despoiled before her eyes, expresses but a moderate show of distress. But while the paternal head of the household can be so deeply concerned for the welfare of his family, and the preservation of his home, it is a noteworthy fact that even while bewailing her misfortunes in the most agonizing manner possible, the mother-bird is often known to stop in the midst of her lamentations to seize a passing insect.
The young are objects of the ten derest solicitude, both parents laboring with unremitting zeal in providing them with plenty of suitable nourishment. Young caterpillars and the larvæ of various other insects which the parents often procure at great distances, are fed to them when quite young, but later on they are subsisted upon plant lice, small spiders and mature diptera and ants. Late in the season both young and old devour great quantities of cedar berries, and the seeds of the commoner grasses. When twelve days old the young leave the nest for the first time, but are not prepared to quit entirely until a week older. They now in company with their parents repair to moist rather than dry thickets, because of the greater abundance of insects to be found in such places, and here they remain until the last of September, when they retire south to winter in Guatemala, and other parts of Central America, as well as in the West Indies and Peru.
About the time of departure, the young male resembles in plumage the mother, but differs in having the upper tail-coverts and tail a deep black color, instead of having the former olive and the latter dusky. In addition the dorsal region is more greenish-olive, and the abdomen and crissum of a purer white. He is slow in acquiring the perfect adult plumage, and does not attain to it until his third year. At or about this time his predominant color is black. This is variegated by the white abdomen and under tail-coverts, and by a central band on the breast of the same color, and still further by the bases of all the quills (excepting the inner and outer proximal halves of all the tail-feathers but the middle,) a patch on each side of the breast, and the axillary region, being of an orange-red hue, which shades to a vermilion on the breast. The female has the black replaced by olive-green above, and brownish-white below. Yellow takes the place of orange, and ash that of black upon the head. There is also a grayish-white line and ring around the eye. Their length is five and a quarter inches, wing two and a half, and tail two and nine-twentieths.
The eggs of the Redstart are four in number, and bear some resemblance to those of the common Blue-eyed Yellow Warbler. Their groundcolor is a grayish-white, and this is quite thickly sprinkled all over, but more especially about the larger extremity, with shades of brown and black. They vary in length from .54 to .67 of an inch, and in breadth from .44 to .53. Specimens from widely separated localities, when compared with others from the Middle Atlantic States, show the same amount of variation in size and general appearance. In Eastern Pennsylvania the species is single-brooded, and the same may be said of other sections of the country which the birds frequent.