NEW THOUGHTS ABOUT NESTS
Our sense of smell is not so keen as that of a dog, who can detect the tiny quail while they are still invisible; nor have we the piercing sight of the eagle who spies the grouse crouching hundreds of feet beneath his circling flight; but when we walk through the bare December woods there is unfolded at last to our eyes evidence of the late presence of our summer’s feathered friends—air castles and tree castles of varied patterns and delicate workmanship.
Did it ever occur to you to think what the first nest was like—what home the first reptile-like scale flutterers chose? Far back before Jurassic times, millions of years ago, before the coming of bony fishes, when the only mammals were tiny nameless creatures, hardly larger than mice; when the great Altantosaurus dinosaurs browsed on the quaint herbage, and Pterodactyls—those ravenous bat-winged dragons of the air—hovered above the surface of the earth,—in this epoch we can imagine a pair of long-tailed, half-winged creatures which skimmed from tree to tree, perhaps giving an occasional flop—the beginning of the marvellous flight motions. Is it not likely that the Teleosaurs who watched hungrily from the swamps saw them disappear at last in a hollowed cavity beneath a rotten knothole? Here, perhaps, the soft-shelled, lizard-like eggs were laid, and when they gave forth the ugly creaturelings did not Father Creature flop to the topmost branch and utter a gurgling cough, a most unpleasant grating sound, but grand in its significance, as the opening chord in the symphony of the ages to follow?—until now the mockingbird and the nightingale hold us spellbound by the wonder of their minstrelsy.
Turning from our imaginary picture of the ancient days, we find that some of the birds of the present time have found a primitive way of nesting still the best. If we push over this rotten stump we shall find that the cavity near the top, where the wood is still sound, has been used the past summer by the downy woodpecker—a front door like an auger hole, ceiling of rough-hewn wood, a bed of chips!
The chickadee goes a step further, and shows his cleverness in sometimes choosing a cavity already made, and instead of rough, bare chips, the six or eight chickadee youngsters are happy on a hair mattress of a closely woven felt-like substance.
Perhaps we should consider the kingfisher the most barbarous of all the birds which form a shelter for their home. With bill for pick and shovel, she bores straight into a sheer clay bank, and at the end of a six-foot tunnel her young are reared, their nest a mass of fish bones—the residue of their dinners. Then there are the aerial masons and brickmakers—the eave swallows, who carry earth up into the air, bit by bit, and attach it to the eaves, forming it into a globular, long-necked flask. The barn swallows mix the clay with straw and feathers and so form very firm structures on the rafters above the haymows.
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. |