Yet among the majority of our song-birds the male is most conspicuous both by his color and manners and by his song, and is to that extent a shield to the female. It is thought that the female is humbler clad for her better concealment during incubation. But this is not satisfactory, as in some cases she is relieved from time to time by the male. In the case of the domestic dove, for instance, promptly at midday the cock is found upon the nest. I should say that the dull or neutral tints of the female were a provision of nature for her greater safety at all times, as her life is far more precious to the species than that of the male. The indispensable office of the male reduces itself to little more than a moment of time, while that of his mate extends over days and weeks, if not months.[Footnote]
[Footnote] A recent English writer upon this subject presents an array of facts and considerations that do not support this view. He says that, with very few exceptions, it is the rule that, when both sexes are of strikingly gay and conspicuous colors, the nest is such as to conceal the sitting bird; while, whenever there is a striking contrast of colors, the male being gay and conspicuous, the female dull and obscure, the nest is open and sitting bird exposed to view. The exceptions to this rule among European birds appear to be very few. Among our own birds, the cuckoos and the blue jays build open nests, without presenting any noticeable difference in the coloring of the two sexes. The same is true of the pewees, the kingbird, and the sparrows, while the common bluebird, the oriole, and the orchard starling afford examples the other way.
In migrating northward, the males have abandoned their nests, or rather chambers, which they do after the first season, their cousins, the nuthatches, chickadees, and brown creepers, fall heir to them. These birds, especially the creepers and nuthatches, have many of the habits of the Picidae, but lack their powers of bill, and so are unable to excavate a nest for themselves. Their habitation, therefore, is always second-hand. But each species carries in some soft material of various kinds, or in other words, furnishes the tenement to its liking. The chickadee arranges in the bottom of the cavity a little mat of a light felt-like substance, which looks as if is came from the hatter's, but which is probably the work of numerous worms or caterpillars. On this soft lining the female deposits six speckled eggs.
I recently discovered one of these nests in a most interesting situation. The tree containing it, a variety of wild cherry, stood upon the brink of the bald summit of a high mountain. Gray, timeworn rocks lay piled loosely about, or overtoppled the just visible byways of the red fox. The trees had a half-scared look, and that indescribable wildness which lurks about the tops of all remote mountains possessed the place. Standing there, I looked down upon the back of the red-tailed hawk as he flew out over the earth beneath me. Following him, my eye also took in farms and settlements and villages and other mountain ranges that grew blue in the distance.
The parent birds attracted my attention by appearing with food in their beaks, and by seeming much put out. Yet so wary were they of revealing the locality of their brood, or even of the precise tree that held them, that I lurked around over an hour without gaining a point on them. Finally a bright and curious boy who accompanied me secreted himself under a low, projected rock close to the tree in which we supposed the nest to be, while I moved off around the mountain-side. It was not long before the youth had their secret. The tree which was low and wide-branching, and overrun with lichens, appeared at a cursory glance to contain not one dry or decayed limb. Yet there was one a few feet long, in which, when my eyes were piloted thither, I detected a small round orifice.
As my weight began to shake the branches, the consternation of both old and young was great. The stump of a limb that held the nest was about three inches thick, and at the bottom of the tunnel was excavated quite to the bark. With my thumb I broke the thin wall, and the young, which were full-fledged, looked out upon the world for the first time. Presently one of them, with a significant chirp, as much to say, "It is time we were out of this," began to climb up toward the proper entrance. Placing himself in the hole, he looked around without manifesting any surprise at the grand scene that lay spread out before him. He was taking his bearings, and determining how far he could trust the power of his untried wings to take him out of harm's way. After a moment's pause, with a loud chirrup, he launched out and made tolerable headway. The others rapidly followed. Each one, as it started upward, from a sudden impulse, contemptuously saluted the abandoned nest with its excrement.
Though generally regular in their habits and instincts, yet the birds sometimes seem as whimsical and capricious as superior beings. One is not safe, for instance, in making any absolute assertion as to their place or mode of building. Ground-builders often get up into a bush, and tree-builders sometimes get upon the ground or into a tussock of grass. The song sparrow, which is a ground builder, has been known to build in the knothole of a fence rail; and a chimney swallow once got tired of soot and smoke, and fastened its nest on a rafter in a hay barn. A friend tells me of a pair of barn swallow which, taking a fanciful turn, saddled their nest in the loop of a rope that was pendent from a peg in the peak, and liked it so well that they repeated the experiment next year. I have know the social sparrow, or "hairbird" to build under a shed, in a tuft of hay that hung down, through the loose flooring, from the mow above. It usually contents itself with half a dozen stalks of dry grass and a few long hair from a cow's tail loosely arranged on the branch of an apple-tree. The rough-winged swallow builds in the wall and in old stone-heaps, and I have seen the robin build in similar localities. Others have found its nest in old, abandoned wells. The house wren will build in anything that has an accessible cavity, from an old boot to a bombshell. A pair of them once persisted in building their nest in the top of a certain pump-tree, getting in through the opening above the handle. The pump being in daily use, the nest was destroyed more than a score of times. This jealous little wretch has the wise forethought, when the box in which he builds contains two compartments, to fill up one of them, so as to avoid the risk of troublesome neighbors.
The less skillful builders sometimes depart from their usual habit, and take up with the abandoned nest of some other species. The blue jay now and then lays in an old crow's nest or cuckoo's nest. The crow blackbird, seized with a fit of indolence, drops its eggs in the cavity of a decayed branch. I heard of a cuckoo that dispossessed a robin of its nest; of another that set a blue jay adrift. Large, loose structures, like the nests of the osprey and certain of the herons, have been found with half a dozen nests of the blackbirds set in the outer edges, like so many parasites, or, as Audubon says, like the retainers about the rude court of a feudal baron.
The same birds breeding in a southern climate construct far less elaborate nests than when breeding in a northern climate. Certain species of waterfowl, that abandon their eggs to the sand and the sun in the warmer zones, build a nest and sit in the usual way in Labrador. In Georgia, the Baltimore oriole places its nest upon the north side of the tree; in the Middle and Eastern States, it fixes it upon the south or east side, and makes it much thicker and warmer. I have seen one from the South that had some kind of coarse reed or sedge woven into it, giving it an open-work appearance, like a basket.
Very few species use the same material uniformly. I have seen the nest of the robin quite destitute of mud. In one instance it was composed mainly of long black horse-hairs, arranged in a circular manner, with a lining of fine yellow grass; the whole presenting quite a novel appearance. In another case the nest was chiefly constructed of a species of rock moss.