Bird egg

“ The harder shell of its own egg, considered in relation to the destructive egg-breaking habit of the bird, gives it the best chance of being preserved; for though the Cow-bird never distinguishes its own eggs, of which indeed it destroys a great many, a larger proportion escape in a nest where many eggs are indiscriminately broken.
2. The vitality or tenacity of life appears greater in the embryo Cow-bird than in other species; this circumstance also, in relation to the egg-breaking habit and to the habit of laying many eggs in a nest, gives it a further advantage. ”

“ It is true that birds cannot be classified according to the eggs they produce, but at the same time it is equally true that a bird's egg may be a valuable clue to show us where we should expect to find its nearest allies or, on the other hand, may cause us to suspect that it should be removed from amongst those with which it is now placed!. ”

“ A week after this a friend found another Thrush's egg on the ground in a field, and I myself found a new-laid Sparrow's egg in the middle of a tennis-court. It seems to me that the most probable reason for eggs being laid on the ground is either that the bird has been disturbed while in the act of laying, and has been obliged to lay the egg before it was able to get back to the nest, or that the bird has deserted its nest when it has only laid, say, two eggs, and has been obliged to lay the remaining three (in the case of its laying five) somewhere outside the nest. ”

“ When this happens the Cow-bird’s egg is lost if incubation is far advanced; but if the eggs have been sat on three or four days only, then it has a good chance of being hatched and the young bird reared along with its foster-brothers.
4. One female often lays several eggs in the same nest, instead of laying only one, as does, according to Wilson, the Molothrus pecoris- 75 - of North America. I conclude that this is so from the fact that in cases where the eggs of a species vary considerably in form, size, and markings, each individual of the species lays eggs precisely or nearly alike. ”

“ Mechanical Construction of Eggs.—We now come to another phase of the protective principle, even more remarkable than those we have already discussed, and equally useful. This is in the mechanical construction of eggs to suit their situation and surrounding conditions. What an admirable provision Nature has shown in placing the axis of a bird's egg just where it will prevent it rolling off a flat surface, such as a ledge of rock, when moved by the terrible gusts of wind that sweep over high latitudes, or perhaps roughly moved by the parent bird suddenly fluttering off when scared. ”

“ When the time for domestic cares arrives the bird lays a single white egg on the branch which has served as its perch, or at the junction of a limb and the tree-trunk, without making any sort of a nest. Doubtless many eggs roll off this precarious location and are broken. It feeds upon beetles and insects which are caught on the wing, and some observers say that it also catches small birds ”

“ These eggs measure 1.18 inches in length by .87 of an inch in breadth. Their ground-color, seen through a magnifying glass, is of clear crystal whiteness, but is so closely covered by overlaying markings as not to be discernible to the eye. They are marked over the entire surface with small irregular confluent spots and blotches, which are a blending of black, umber, and purplish-gray markings. These combinations give to the egg the appearance of a piece of polished marble of a dark gray color. They are both smaller and of a lighter color than those of the common eastern bird. ”

“ Some of them on the face of the rock, or in a shallow fissure, and which have been occupied for years, are piled up to the height of from three to five feet, but in this case they always lean against the rock. The egg, which is solitary, and presents nothing remarkable in its position, is of an elongated oval form, bluish-white, dull, with a chalky surface, usually patched with yellowish-brown dirt. It is subjected to what might appear rough usage, for the bird in alighting, flying off, or when disturbed by the intrusion of human visitors, tosses it about, and often stands upon it. ”

“ As soon as an egg becomes large and heavy enough to be cumbersome to the bird, it is removed from the body. A shell, impervious to air, protects the germ of life within, until from two to twenty eggs have accumulated, and then, although laid at different intervals, their incubation commences together, and the young birds are hatched at the same time. ”

“ They nest anywhere, where they can find or make a suitable cavity for the reception of their eggs; in trees in woods or solitary trees in large pastures, in apple trees in orchards, in fence posts, in holes under the roofs of buildings, etc. They ordinarily lay from five to ten very glossy eggs, but it has been found that they will continue laying, if one egg is removed from the nest at a time, until in one case seventy-one eggs were secured. Fresh eggs may be found at any time from May until August, as they frequently raise two broods a season. ”

“ Many close observers now reject this idea because they find that birds supplied with digestible mineral foods do not eat those that are not digestible. A bird does not need teeth to grind its food, because it is softened in the crop and the gastric juice acts upon it before the grinding process begins.
Peculiarities of birds' eggs. The only animal foodstuff produced in a natural package, easily preserved and handled, is the egg. In the vegetable world we have a great many such things—fruits, seeds, roots, nuts, with coverings of various textures to protect the contents from the air. ”

“ It may be asked if the egg of a bird is the same as the egg of a mammal. The mature bird's egg, as it is laid in the nest, differs materially from that of any mammal; but in its miniature form, as found in the hen's ovary, it is also the same. The egg of a bird after it leaves the ovary, and as it passes along the oviduct, takes on secretions in its passage which it converts into yelk, and afterwards a shell is added to give it protection in the external world, where it must undergo incubation before it can become a bird ”

“ It will require the aid of a microscope to discover and observe the object of our search and study. The egg of the bird bears some proportion to the size of its producer, for in them is stored up the nourishment which is to maintain the unfolding life that can be fed in no other way until it has reached an advanced stage of maturity, and has broken its shell and emerged into the outer world. The human egg is so small that it would require two hundred and forty of them laid side by side to make one inch in length. ”

“ Take only one specimen, and not until you have reason to believe the bird has done laying. Never under any circumstances take an egg when you have ground to suppose incubation has commenced, or is in an advanced stage, for besides the cruelty of the thing, it will often be of no use. ”

“ Its fecundity is wonderful. There is, perhaps, no bird that will excel it as an egg producer for market. Its patrons are enthusiastic in its praise and claim an average yield of one hundred and seventy-five to two hundred eggs per year from each of their birds, but their small size, four to four and a half pounds, together with their dark pins, militates against their value as a market bird. ”

“ It may be, however, that coloration of this kind is less conspicuous than is generally supposed, but in any case the safety of the egg depends not so much on its coloration as on the character of the nest, which, where protective devices are necessary, must harmonize sufficiently with its surroundings to escape observation from prowling egg-stealers of all kinds.
The size of the egg depends partly on the number produced and partly on the conditions determining the state of the young bird at hatching: hence there is a great disparity in the relative sizes of the eggs of different birds. ”

“ Many females lay in the same hole, for a dozen eggs are often found together, and these are so large that it is not possible for the body of the bird to contain more than one fully-developed egg at the same time. ”

“ This is about the size of the eye of a small bird in new-laid eggs, but is increased as much as ten times in the process of hatching. The air bag is of such great importance to the development of the chicken—probably by supplying it with a limited atmosphere of oxygen—that, if the blunt end of an egg be pierced with the point of the smallest needle, the egg cannot be hatched. ”

“ It values its neatly finished nest too highly to desert it, and it is not strong enough to lift the big egg and throw it over the edge, so it gathers a new supply of hay and hair, and makes a false bottom to cover up the egg. Then it makes a new lining to the nest, and lays its own eggs upon that, so that the cow-bird's egg does not receive any of the warmth from its body, and never hatches.
EGG OF COW-BIRD.
I have given you several reasons for believing that birds are able to think for themselves ”

“ The largest eggs are those of birds; and this because, to the minute essential portion of the egg, or germ, from which the young bird grows, there is added a large store of food-material—the yolk and white of the egg—destined to nourish the growing embryo while the whole is enclosed within a hard shell. ”

“ This egg I replaced in the nest by lifting it with the broad end of the boat oar. thinking, perhaps, that handling it might cause the Loon to desert the nest. The egg that was in the water was many shades lighter in color than the one found in the nest, which leads me to believe that the eggs of birds that habitually breed in damp mud nests acquire a darker color from stains. ”

“ The eggs of the foster-bird are yet unhatched, and soon after disappear. In every case the Cow Bird's egg is the first hatched, and herein also is manifested the wisdom of Nature; for the parent-birds finding a helpless object, for whose subsistence it behoves them to provide, fly off to procure food for it. ”

“ The affection of the unexperienced and untaught bird to its egg, which induces it to sit days and weeks upon it to warm the enclosed embryon, is a matter of great difficulty to explain; See Additional Note IX. on Storge. Concerning the fabrication of their nests, see Zoonomia, Sect. XVI. 13. on instinct. [Back to Canto]
Hears the young prisoner, l. 351. The air-vessel at the broad end of an incubated egg gradually extends its edges along the sides of the shell, as the chick enlarges, but is at the same time applied closer to the internal surface of the shell ”

“ “The bird fights its way out of the egg. The egg is the world. Whoever will be born must [Pg 116] destroy a world. The bird flies to God. ”

“ I have even known the eggs carelessly dropped on the bare ground in a corner of a potato-field, and have found the female sitting on her eggs in all the bright glare of a noonday sun in June, and to all appearance undisturbed by its brilliance. A more common situation for the eggs is a slight hollow of a bare rock, the dark weather-beaten shades of which, with its brown and slate-colored mosses and lichens, resembling both the parent and the egg in their coloring, are well adapted to screen them from observation or detection. ”

“ But what did he see in the clear stream below? His own image; no longer a dark, gray bird, ugly and disagreeable to look at, but a graceful and beautiful swan.
To be born in a duck's nest, in a farmyard, is of no consequence to a bird, if it is hatched from a swan's egg. ”

“ The number of eggs varies from three to seven, and are frequently laid long before the ice and snow have disappeared. “The eggs vary from oval to oblong oval in shape, are pure white in color, and somewhat glossy, the shell is smooth and fine-grained.” Incubation begins as soon as the first egg is laid, and both sexes participate in this duty, and occasionally both are found on the nest at the same time. At the nesting season the courage of both sexes is very marked. The male will fight with its talons, and even when wounded will still defend itself. ”

“ It may be hard for an egg to turn into a bird: it would be a jolly sight harder for it to learn to fly while remaining an egg. We are like eggs at present. And you cannot go on indefinitely being just an ordinary, decent egg. We must be hatched or go bad. ”

“ Her eggs are one of the world's small wonders. They lie out in the open like so many of the pebbles about them—resembling the stones so perfectly that they are more often overlooked or crushed than discovered. The ground color [Pg 204] of the egg is that of the earth, and the markings correspond marvelously to the size, shade, and distribution of the bits of wood beneath them in the nest. I know of no other instance of protective coloring among the birds so nearly perfect, unless it be the killdeer herself when playing her favorite trick of "invisible." ”

“ When the eggs are near hatching, the female will not leave her eggs under any circumstances, and will suffer herself to be made a prisoner rather than abandon them. The mother assists the young birds to extricate themselves from the egg-shell, caresses and dries them with her bill, and aids them in their first efforts to totter out of the nest. ”

“ Many females, he thinks, deposit their eggs together; and he expresses the opinion that the number of eggs which each individual lays is two, although he was not able absolutely to assure himself of this. He describes them as nearly round, and of a light greenish-white. An egg of this species from Louisiana is of a rounded oval shape, equally obtuse at either end, and of a uniform dull-white color. ”