But what of the many nests of grasses and twigs which we find in the woods? How closely they were concealed while the leaves were on the trees, and how firm and strong they were while in use, the strongest wind and rain of summer only rocking them to and fro! But now we must waste no time or they will disappear. In a month or more almost all will have dissolved into fragments and fallen to earth—their mission accomplished.
Some look as if disintegration had already begun, but if we had discovered them earlier in the year, we should have seen that they were never less fragile or loosely constructed than we find them now. Such is a cuckoo’s nest, such a mourning dove’s or a heron’s; merely a flat platform of a few interlaced twigs, through which the eggs are visible from below. Why, we ask, are some birds so careless or so unskilful? The European cuckoo, like our cowbird, is a parasite, laying her eggs in the nests of other birds; so, perhaps, neglect of household duties is in the blood. But this style of architecture seems to answer all the requirements of doves and herons, and, although with one sweep of the hand we can demolish one of these flimsy platforms, yet such a nest seems somehow to resist wind and rain just as long as the bird needs it.
Did you ever try to make a nest yourself? If not, sometime take apart a discarded nest—even the simplest in structure—and try to put it together again. Use no string or cord, but fasten it to a crotch, put some marbles in it and visit it after the first storm. After you have picked up all the marbles from the ground you will appreciate more highly the skill which a bird shows in the construction of its home. Whether a bird excavates its nest in earth or wood, or weaves or plasters it, the work is all done by means of two straight pieces of horn—the bill.
There is, however, one useful substance which aids the bird—the saliva which is formed in the mucous glands of the mouth. Of course the first and natural function of this fluid is to soften the food before it passes into the crop; but in those birds which make their nests by weaving together pieces of twig, it must be of great assistance in softening the wood and thus enabling the bird readily to bend the twigs into any required position. Thus the catbird and rose-breasted grosbeak weave.
Given a hundred or more pieces of twigs, each an inch in length, even a bird would make but little progress in forming a cup-shaped nest, were it not that the sticky saliva provided cement strong and ready at hand. So the chimney swift finds no difficulty in forming and attaching her mosaic of twigs to a chimney, using only very short twigs which she breaks off with her feet while she is on the wing.
How wonderfully varied are the ways which birds adopt to conceal their nests. Some avoid suspicion by their audacity, building near a frequented path, in a spot which they would never be suspected of choosing. The hummingbird studs the outside of its nest with lichens, and the vireo drapes a cobweb curtain around her fairy cup. Few nests are more beautiful and at the same time more durable than a vireo’s. I have seen the nests of three successive years in the same tree, all built, no doubt, by the same pair of birds, the nest of the past summer perfect in shape and quality, that of the preceding year threadbare, while the home which sheltered the brood of three summers ago is a mere flattened skeleton, reminding one of the ribs and stern post of a wrecked boat long pounded by the waves.
The subject of nests has been sadly neglected by naturalists, most of whom have been chiefly interested in the owners or the contents; but when the whys and wherefores of the homes of birds are made plain we shall know far more concerning the little carpenters, weavers, masons, and basket-makers who hang our groves and decorate our shrubbery with their skill. When on our winter’s walk we see a distorted, wind-torn, grass cup, think of the quartet of beautiful little creatures, now flying beneath some tropical sun, which owe their lives to the nest, and which, if they are spared, will surely return to the vicinity next summer.
| That time of year thou may’st in me behold, When yellow leaves, or none, or few, do hang Upon those boughs which shake against the cold,— Bare, ruin’d choirs, where late the sweet birds sang. SHAKESPEARE. |