THE Eggs of Birds are variously tinted and mottled, and hence they become objects of interest to the collector. In this diversity of colour nature has, doubtless, some final object in view; and though not in every instance, yet in many, we can certainly see a design in the adaptation of the colours to the purpose of concealment, according to the habits of the various classes of Birds. Thus, as a general rule, the Eggs of Birds which have their nests in dark holes, or which construct nests that almost completely exclude the light, are white; as is also the case with those Birds that constantly sit on their Eggs, or leave them only for a short time during the night. Eggs of a light blue or light green tint will also be found in nests that are otherwise well concealed; while, on the other hand, a great proportion of those nests that are in exposed situations have Eggs varying in tints and spots in a remarkable degree, corresponding with the colours of external objects in their immediate neighbourhood. Thus, a dull green colour is common in most gallinaceous Birds that form their nests in grass, and in aquatic Birds among green hedges; a bright green colour is prevalent among Birds that nestle among trees and bushes; and a brown mottled colour is found in those Eggs that are deposited among furze, heath, shingle, and grey rocks and stones.

Birds'-nesting, we need hardly remark, is a favourite pursuit of boyhood; but, in some cases, its attractions have induced young persons to take up more important branches of natural history, or the collection, systematic arrangement, and comparison of Birds' Eggs, which is, in scientific study, termed Oology; and as the study of Birds cannot be considered complete until they are known in every stage, it forms a branch of Ornithology. In this case Birds'-nesting has an useful object; but many persons are content to acquire collections of Eggs without troubling themselves about the Birds which have laid them.

The late Mr. John Wolley, M.A., was one of the leading authorities upon the subject of European Ornithology, and was one of a number of University men, who, about twelve years ago, established the ornithological journal called "The Ibis," and who visited far-distant and unexplored regions, where they might hope to discover strange Birds and unknown Eggs. For several years Algiers and Tunis were their favourite resorts, and the meeting-places of many of our rarer Birds were hunted up in these countries, even so far as the Desert of the Great Sahara. Others preferred the New World as the scene of their labours, and collected long series of specimens in the highland of Guatemala, and the tropical forests of Belize. Mr. Wolley, however, confined his attention principally to the northern parts of Europe—that region being the breeding-quarters of a large number of Birds which are only known in this country as winter visitants. In order to be at his collecting-station at Muonioniska, on the frontier of Finnish Lapland, at the earliest commencement of the breeding-season, Mr. Wolley frequently passed the whole winter in that remote region. But the rigour of the climate under the Arctic Circle contributed to bring on a malady which terminated fatally in November, 1859.

Upon the decease of Mr. Wolley, his large collection of Birds' Eggs, in accordance with his last wishes, became the property of his friend, Mr. Alfred Newton, who is publishing a Catalogue of Mr. Wolley's Egg Cabinet, with notes from the deceased naturalist's journals. The first part contains the Eggs of Birds of Prey (Accipitres), recognisable at once by their strongly-hooked bill, formed to assist them in tearing their prey, and their large feet and sharpened claws, which aid them to grasp it. They are divisible into two very distinct groups—the diurnal Birds of Prey, consisting of the Hawks, Vultures, and Eagles; and the nocturnal Birds of Prey, or Owls. In the latter the Eggs are invariably colourless; in the former they are often strongly marked, and present some of the most beautiful objects in the whole series of Birds' Eggs.

In the most recently published list of European birds fifty-two species of birds of prey are given as occurring more or less frequently within the limits of our continent. Of the three generally-recognised species of European Vultures two are well represented, as regards their eggs, in the Wolleyan series. A few years ago the nesting of all these birds was utterly unknown to naturalists, and it was mainly through the exertions of Mr. Wolley and his friends that specimens first reached our collectors' cabinets. Here were found both the Egyptian Vulture and the Griffon breeding abundantly in the Eastern Atlas in 1857; and the eyries of these birds have since been visited by other collectors in the same country. The Eggs of the former of these Vultures are remarkable for their deep and rich coloration. The productions of the Griffon are not nearly so handsome, and are occasionally altogether destitute of markings. Of the Eagles of Europe the series of Eggs is very full, especially of the two well-known British species—the Golden Eagle and Sea Eagle. The Golden or Mountain Eagle is even now-a-days much more common in the remote parts of the British islands than is usually supposed to be the case. In 1852 Mr. Wolley was acquainted with five nests of this bird in various parts of Scotland, and there were undoubtedly at least as many more of which he did not learn the particulars. The eyrie is usually placed in some mountainous district, on the ledge of some "warm-looking" rock, well clothed with vegetation, and often by no means wild or exposed. Not unfrequently, under proper guidance, one can walk into the nest almost without climbing. Mr. Newton gives a very entertaining account of the taking of a pair of eggs from a nest in Argyllshire in 1861, where this seems to have been the case. In the whole ascent there was only one "ticklish place," where it was necessary to go sideways on a narrow ledge round some rocks. The Sea Eagle, on the other hand, generally breeds on the high cliffs upon the coast, often selecting the most inaccessible position for its eyrie. Sometimes, however, it will choose an island in the middle of an inland loch, and in such case places its nest upon the ground or in a tree.

Mr. Wolley's well-written notes of his adventures in quest of both these Eagles, as also those relating to the other rapacious birds, will be read with much interest; as will also the details concerning the nesting-habits of many of the rarer species of European birds, several of which, such as the Rough-legged Buzzard and the Lapp Owl, were first tracked to their breeding-quarters in the remotest wilds of Scandinavia by this indefatigable naturalist. [10]

Of large Eggs we are most familiar with those of the Ostrich, of which Mr. Burchell, when in Africa, found twenty-five Eggs in a hollow scratched in the sand, six feet in diameter, surrounded by a trench, but without grass, leaves, or sticks, as in the nests of other birds. In the trench were nine more Eggs, intended, as the Hottentots observed, as the first food of the twenty-five young Ostriches. Between sixty and seventy Eggs have been found in one nest; each is equal to twenty-four Eggs of the domestic hen, and holds five pints and a quarter of liquid. The shells are dirty white. The Hottentots string them together as belts, or garlands, and they are frequently mounted as cups. One Ostrich Egg is a sufficient meal for three persons. The Egg is cooked over the fire without either pot or water, the shell answering the purpose of the first, and the liquid nature of its contents that of the other.

Less familiar to the reader are the gigantic Eggs of the Epyornis, a bird which formerly lived in Madagascar. One of these Eggs contains the substance of 140 hens' Eggs. Mr. Geoffroy St. Hilaire describes some portions of an Egg of the Epyornis which show the Egg to have been of such a size as to be capable of containing about ten English quarts; that in the Museum of the Jardin des Plantes can only contain 8-3/4 quarts. Mr. Strickland, in some notices of the Dodo and its kindred, published in 1849, says that in the previous year a Mr. Dumarele, a French merchant at Bourbon, saw at Port Leven, Madagascar, an enormous Egg which held "thirteen wine quart bottles of fluid." The natives stated that the Egg was found in the jungle, and "that such Eggs were very, very rarely met with."

A word or two about the nests of such gigantic birds. Captain Cook found, on an island near the north-east coast of New Holland, a nest "of a most enormous size. It was built with sticks upon the ground, and was no less than six-and-twenty feet in circumference, and two feet eight inches high." (Kerr's "Collection of Voyages and Travels," xiii., 318.) Captain Flinders found two similar nests on the south coast of New Holland, in King George's Bay. In his "Voyage," &c., London, 1818, he says, "They were built upon the ground, from which they rose above two feet, and were of vast circumference and great interior capacity; the branches of trees and other matter of which each nest was composed being enough to fill a cart."

Among the varieties of Birds'-nests are some very curious homes, of which we have but space to notice a few. The pendulous nest of the Indian Baya-bird is usually formed of the fibres of the palmyra, the cocoa-nut palm, and wild date of India, sometimes mixed with grass, neatly interlaced, and very strongly made. It consists of only one circular chamber, with a long tubular passage leading to it, and is suspended from a tree, preferred if overhanging water. The natives of India say the Baya lights up its nest with fire-flies. The bird lays from four to six white eggs. Bayas are of a very social disposition: numbers build on the same tree, or neighbouring trees, and singing in concert during the breeding season. The Baya is very docile, and taught to fly off the finger and return again; to dart after a ring or small coin, dropped into a deep well, and catch it before it reaches the water; to fetch and carry, and perform similar tricks.

The nest of the brilliant Golden-banded Oriole is a hammock of twisted fibrous substances, and is suspended in a low shrub, so as to swing to the breeze. The twine-like fibres of which it is woven are the filaments of the gigantic palm. The threads break away from the leaf, and hang like fringe to the magnificent foliage.

The Tailor-birds are the best nest-builders of all the feathered tribes. They interweave their nests between the twigs and branches of shrubs, or suspend the nests from them; and some of these birds have exercised arts from the creation which man has found of the greatest benefit to him since he discovered them. These birds, indeed, may be called the inventors of the several arts of the weaver, the sempstress, and the tailor; whence some of them have been denominated Weaver and Tailor Birds. The nests of the latter are, however, most remarkable. India produces several species of Tailor-birds that sew together leaves for the protection of their eggs and nestlings from the voracity of serpents and apes. They generally select the end of a branch or twig, and sew with cotton, thread, and fibres. Colonel Sykes has seen some in which the thread was literally knotted at the end. The inside of these nests is lined usually with down and cotton.

Tailor-birds are not confined to India or tropical countries. Italy can boast a species which exercises the same art. Mr. Gould has a specimen of this bird in his possession, and the Zoological Society have a nest in their Museum. This little bird, a species of the genus sylvia, in summer and autumn frequents marshes; but in the spring it seeks the meadows and corn-fields, in which, at that season, the marshes being bare of the sedges which cover them in summer, it is compelled to construct its nest in tussocks of grass on the brinks of ditches; but the leaves of these being weak, easily split, so that it is difficult for our little sempstresses to unite them, and so form the skeleton of the fabric. From this and other circumstances, the spring nests of these birds differ so widely from those made in the autumn that it seems next to impossible that both should be the work of the same artisan. The latter are constructed in a thick bunch of sedge or reed: they are shaped like a pear, being dilated below and narrow above, so as to leave an aperture sufficient for the ingress and egress of the bird. The greatest horizontal diameter of the nest is about two inches and a half, and the vertical is five inches.

The most wonderful thing in the construction of these nests is the method to which the little bird has recourse to keep united the living leaves of which it is composed. The sole in the weaving, more or less delicate, of the materials, forms the principle adopted by other birds to bind together the walls of their nests; but this sylvia is no weaver, for the leaves of the sedges or reeds are united by real stitches. In the edge of each leaf she makes, probably with her beak, minute apertures, through which she contrives to pass, perhaps by means of the same organ, one or more cords formed of spiders' web, particularly that of their egg-pouches. Those threads are not very long, and are sufficient to pass two or three times from one leaf to another. They are of unequal thickness, and have knots here and there, which, in some places, divide into two or three branches.

This is the manner in which the exterior of the nest is formed: the interior consists mainly of down, chiefly from plants, a little spiders' web being intermixed, which helps to keep the other substances together. The upper part and sides of the nest, that is, the external and internal, are in immediate contact; but in the lower part a greater space intervenes, filled with the slender foliage of grasses, and other materials, which render soft and warm the bed on which the eggs are to repose. This little bird feeds on insects. Its flight is rectilinear, but consists of many curves, with the concavity upwards. These curves equal in number the strokes of the wing, and at every stroke its whistle is heard, the intervals of which correspond with the rapidity of its flight.

The Australian Bower-bird, as its name implies, builds its nest like an arbour or bower, with twigs: in the British Museum are two specimens, each decorated—one with bones and fresh-water shells, and the other with feathers and land-shells; remarkable instances of taste for ornament already referred to in a preceding page. The Satin or Bower-bird is described by settlers in Australia as "a very troublesome rascal," which besets gardens; if once allowed to make a lodgment there it is very troublesome to get rid of him; he signalizes his arrival by pulling up, in his restless fussy way, everything in the garden that he can tug out of the ground, even to the little sticks to mark the site of seeds. A settler had formed a garden in the bush; there was no enclosure of the kind for miles in any direction: a flock of Bower-birds came; he got his gun and shot two or three; the flock went off, and he never saw another bird of the kind.

The Cape Swallows build nests which show extraordinary instinct allied to reason. A pair of these built their nest on the outside of a house at Cape Town against the angle formed by the wall and the board which supported the eaves. The whole of this nest was covered in, and it was furnished with a long neck or passage, through which the birds passed in and out. It resembled a longitudinal section of a Florence oil flask. This nest having crumbled away after the young birds had quitted it, the same pair, or another of the same species, built on the old foundation again. But this time an improvement was observable in the plan of it that can hardly be referred to the dictates of mere instinct. The body of the nest was of the same shape as before, but instead of a single passage it was furnished with one at each side, running along the angle of the roof; and on watching the birds, they were seen invariably to go in at one passage and come out at the other. Besides saving themselves the trouble of turning in the nest and disturbing, perhaps, its interior arrangement, they were guarded by this contrivance against a surprise by serpents, which frequently creep up along the wall, or descend from the thatch, and devour both the mother and her brood.

Dr. Livingstone relates a very curious instance of "Bird Confinement" under very strange circumstances. In passing through Mopane country, in South Africa, his men caught a great number of the birds called KorwÉ in their breeding-places, which were holes in the mopane trees. They passed the nest of a KorwÉ just ready for the female to enter; the orifice was plastered on both sides, but a space was left of a heart shape, and exactly the size of the bird's body. The hole in the tree was in every case found to be prolonged some distance upwards above the opening, and thither the KorwÉ always fled to escape being caught. In another nest that was found, one white egg, much like that of a pigeon, was laid, and the bird dropped another when captured: she had four besides in the ovarium. Dr. Livingstone first saw this bird at Kolenbeng in the forest: he saw a slit only, about half an inch wide and three or four inches long, in a slight hollow of a tree; a native broke the clay which surrounded the slit, put his arm into the hole, and brought out a red-beaked Hornbill, which he killed. He told Dr. Livingstone that when the female enters her nest she submits to a real confinement. The male plasters up the entrance, leaving only a narrow slit by which to feed his mate, and which exactly suits the form of his beak. The female makes a nest of her own feathers, lays her eggs, hatches them, and remains with the young till they are fully fledged. During all this time, which is stated to be two or three months, the male continues to feed her and the young family. The prisoner generally becomes quite fat, and is esteemed a very dainty morsel by the natives; while the poor slave of a husband gets so lean that, on the sudden lowering of the temperature, which sometimes happens after a fall of rain, he is benumbed, falls down, and dies.

Dr. Livingstone, on passing the same tree at Kolenbeng about eight days afterwards, found the hole plastered up again, as if, in the short time that had elapsed, the disconsolate bird-husband had procured another wife. Dr. L. saw a nest with the plastering not quite finished, and others completed; he also received elsewhere, besides Kolobeng, the same account that the bird comes forth when the young are fully-fledged, at the period when the corn is ripe; indeed, her appearance abroad with her young is one of the signs they have for knowing when it ought to be so: the time is between two and three months. She is said sometimes to hatch two eggs, and, when the young of these are full-fledged, the other two are just out of the egg-shells: she then leaves the nest with the two elder, the orifice is again plastered up, and both male and female attend to the wants of the young.

There is a specimen of a nest in the Gardens of the Zoological Society, which merits description, besides that of the Bower-bird. Such is the nest of the Brush Turkey, which appears more like a small haystack than an ordinary nest, and the methodical manner in which it is constructed is thus described:—Tracing a circle of considerable radius, the birds begin to travel round it, continually grasping with their huge feet the leaves and grasses and dead twigs which are lying about, and flinging them inwards towards the centre. Each time that they complete their round, they narrow their circle, so that in a short time they clear away a circular belt, having in its centre a low irregular mass. By repeating the same process, however, they decrease the diameter of the mound as they increase its height, and at last a large and rudely conical mound is formed.

In this nest as many as a bushel of eggs are deposited, at regular intervals, long end downwards. The leaves form a fermenting mass, which relieves the mother of the necessity of setting upon them. The male, however, has to regulate the temperature of the mass, which would otherwise get too hot. This he does by making a central ventilating shaft, which carries off the superfluous heat; and, lest the temperature should fall too low, he is constantly engaged in covering and uncovering the eggs in order to hit the exact temperature to be applied until the egg is warmed into life.

FOOTNOTE:

[10] Abridged from the "Saturday Review."