ask, taught any of the winged tribes that the heat of their bodies was necessary for the developement of the embryo in the egg? The whole subject is full of wonder and instruction, and calculated to overwhelm the mind with devout admiration. "Who knoweth not, in all these, that the hand of the Lord hath wrought this ?" Another circumstance which I may mention, is the remarkable variety observable in the habits of birds in nestbuilding, where the instinct itself is so peculiar, and its general principle so identical. The same form of the nest, and place of building, and materials employed, are rarely, if ever, found united in the architecture of different species; and, indeed, in every one of these particulars, there is generally some specific difference. The house-sparrow builds four or five times in the year, in a variety of situations, under the warm eaves of our houses and sheds, the branch of a clustered fir, or the thick tall hedge which bounds our garden, employing, in all these situations, a mass of straw and hay, and, for a lining, feathers from the poultry-yard. The goldfinch forms the cradle of its young with fine mosses and lichens, collected from the apple or pear tree, compact as felt, lining it with the thistle-down,a model of beautiful construction. A few loose bents and goose-grass, on the other hand, rudely entwined, with perhaps a sprinkling of hair, suffice for the midsummer nests of the white-throat and black-cap. The greenfinch builds carelessly in the hedge, with materials of the coarsest kind; while the chaffinch constructs its anxiously-concealed edifice, with the nicest art, in the neighboring beech or elm. The bull-finch requires fine roots for its nest; the gray fly-catcher chooses cobwebs for the outworks of its building.* It seems as if Provi be equal indications of wise adaptation. The wood-pigeon and the jay, for example, though they erect their fabrics on the tall underwood, in the open air, construct them so slightly, and with such a scanty provision of materials, that they seem scarcely to make sufficient provision for the supply of the brood, and even their eggs may almost be seen through the loosely connected materials. Is it, that there is something in the constitution of the eggs, which makes them less susceptible than others of the alternation of heat and cold? *Journal of a Naturalist. dence had intended that all kinds of portable materials, adapted for the purpose, should be put in requisition by this variety of choice in the different families, so that nothing might be lost, and that one species might not inconveniently interfere with another. "It wins my admiration To view the structure of that little work No glue to join; his little beak was all; And yet, how neatly finished! What nice hand, HURDIS. There is yet another general observation which I may make here, though it relates to the instinct of reproduction, and not of nest-building. I have incidentally stated, that some of the larger birds lay fewer eggs than the smaller. There is, in this, a very remarkable attention to what I have elsewhere called the balance of animal nature. Birds of prey breed slowly; those which are the objects of prey breed rapidly, and in profusion. Thus, the eagle, the condor, and the vulture, lay but two eggs at a time, and produce only once in the year. The falcon, the hawk, and the owl, with all their rapacious congeners, produce also sparingly. The wren, on the contrary, lays ten or even fifteen eggs, and rears this numerous offspring, that they may serve, as it were, to supply the wants of the predatory tribes, to whom their feebleness and unprotected condition render them an easy prey. And so with many other birds. They are prolific in proportion to their exposure to accidents or to enemies; and thus the species is preserved, notwithstanding the destruction to which they are destined. This is a kind of provision which runs through animated nature, and, singular as it is, manifests Creative Intelligence, and that kind of analogy, which, in so many particulars, unites the various departments of creation under one character, and distin guishes the whole as the work of one Almighty Hand. SIXTH WEEK-FRIDAY. BIRDS.-NEST-BUILDING, CONTINUED. IN yesterday's paper, having made some general observations relative to the instincts connected with nest-building, I shall, to-day, select a few instances of peculiarity in this species of architecture, which may serve to illustrate these remarks. I begin with the eagle, which has justly been termed the king of birds. Her nest is usually built, as I have already observed, in some inaccessible cliff of a rock; sometimes shielded from the weather by an overhanging crag, but sometimes also exposed both to the wind and rain. It is flat, though built with considerable labor, and the pains bestowed in erecting it seem only once to be encountered, as she is said to make it her breeding-station for life. Willoughby_thus describes a nest which was found on the Peak of Derby :-"It was made of great sticks, resting one end on the edge of a rock, the other on two birch trees. Upon these was a layer of rushes, and over them a layer of heath, and upon the heath rushes again; upon which lay one young one, and an addle egg ; and, by them, a lamb, a hare, and three heath plants. The nest was about two yards square, and had no hollow in it. The young eagle was of the shape of a goshawk, of almost the weight of a goose, rough-footed, or feathered down to the foot, having a white ring about the tail." The circumstance mentioned of the addle egg, seems to be very common among all the eagle tribes, owing, perhaps, to the flatness of the nest; and it may be regarded as indicating the same providential intention as that already alluded to in regard to the fewness of their eggs. The design is, that this devourer of the more helpless of the quadruped tribes, should be preserved and propagated in sufficient abundance to perform its office of keeping these prolific species within their proper bounds, but should, at the same time, be prevented from itself becoming a pest by over-production. The woodpecker is another bird whose nest is an object of curiosity and admiration, though for a very different reason. This numerous tribe have very remarkable habits in procuring their food; and the instruments with which they are endowed, are admirably fitted to the peculiarity of their condition, which consists in feeding on insects lodged in the interior of decaying trees. These I must not stop at present to describe; but I have to observe that its bill, which is so beautifully contrived for procuring its subsistence, serves also, in this country, to enable it to scoop out for itself a nest, which it does with all the neatness of an experienced workman, in one of the trees where it finds its food. The work is thus graphically described by Wilson :-" About the middle of May, the male and female look out for a suitable place for the reception of their eggs and young. An apple, pear, or cherry-tree, often in the near neighborhood of a farm-house, is generally pitched upon for this purpose. The tree is minutely reconnoitered for several days previous to the operation; and the work is first begun by the male, who cuts out a hole in the solid wood, as circular as if described by a pair of compasses. He is occasionally relieved by the female, both parties working with the most indefatigable diligence. The direction of the hole, if made in the body of the tree, is generally downwards, by an angle of thirty or forty degrees, for the distance of six or eight inches, and then straight down, for ten or twelve more,-within, roomy, capacious, and as smooth as if polished by the cabinet-maker; but the entrance is judiciously left just so large as to admit the bodies of the owners. During this labor, they regularly carry out the chips, often strewing them at a distance, to prevent suspicion. This operation sometimes occupies the chief part of the week." This labor is sufficiently curious; but what is far more worthy of attention, is the total change of instinct in birds of the same species, under other circumstances. There is not, indeed, in the whole history of Nature, a more singular instance of sagacity, if it can be called by that name, than what is displayed by these little winged wonders, in protecting themselves against their enemies. civilized countries, man is the chief foe they have to dread; and the nest we have described suffices for their protection from him. But the case is different in the wide-spread forests of South America. In the depth of these wildernesses, where little is to be apprehended from man, it is not concealment that is necessary, but a situation beyond the reach of those rapacious creatures, which infest the woods, and live by plunder. From the monkey and the snake, which are, in these regions, the natural enemies of the woodpecker, its European nest would be no security. It must select a place which these insidious foes may, indeed, observe, but cannot invade. This, with admirable skill, it accomplishes, by building its nest depending from the most outward branches of a tall tree.* "On one of these immense trees," says Goldsmith, "is seen the most various and the most inimical assemblage of creatures, that can be imagined. The top is inhabited by monkeys of some particular tribe, that drive off all others; lower down, twine about the great trunk, numbers of the larger snakes, patiently waiting till some unwary animal come within the sphere of their activity; and, at the edges of this tree, hang those artificial nests, in great abundance, inhabited by birds of the most delightful plumage." The nest is usually formed in this manner :-When the time of incubation approaches, the woodpeckers fly busily about, in quest of a kind of moss, called, by the English inhabitants of those countries, old-man's-beard. It is a fibrous substance, which bears to be moulded into any form and glued together. This the little bird first * [The author had incautiously added, "such as the banana or the plantain." Now the banana and the plantain are almost exactly alike, and neither of them has any branches at all; the whole plant consisting of large leaves with their footstalks, and an enormous bunch of fruit. And, instead of being "tall," it is rarely more than twenty feet high. It must also be repeated, that little dependence is to be placed on Goldsmith in the minutiae of natural history.—AM. ED.] |