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NIDIFICATION (from Lat. nidus)
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See also:NIDIFICATION (from See also:Lat. nidus) , the See also:process of making a See also:nest (q.v.). Nidification is with most birds the beginning of the breeding See also:season, but with many it is a labour that is scamped if not shirked. Some of the See also:auk tribe See also:place their single See also:egg on a See also:bare ledge of See also:rock, where its See also:peculiar conical shape is but a See also:precarious safeguard when rocked by the See also:wind or stirred by the thronging See also:crowd of its parents' See also:fellows. The See also: The See also:magpie, as though self-conscious that its own thieving habits may be imitated by its neighbours, surrounds its nest with a hedge of thorns. Very many birds of almost every See also:group See also:bore holes in some sandy cliff, and at the end of their See also:tunnel deposit their eggs with or without bedding. Such bedding, too, is very various in See also:character; thus, while the sheldduck and the sand-See also: The See also:clay-built edifices of the See also:swallow and martin are known to everybody, and the See also:nuthatch plasters up the gaping mouth of its nest-hole till only a See also:postern large enough for entrance and exit, but easy of See also:defence, is See also:left. In See also:South See also:America the See also:oven-birds (Furnariidae) construct on the branches of trees globular ovens, so to speak, of mud, wherein the eggs are laid and the young hatched. The See also:flamingo erects in the marshes it frequents a See also:mound of See also:earth sometimes 2 ft. in height, with a cavity atop. The See also:females of the hornbills submit to incarceration during this interesting See also:period, the See also:males immuring them by a barrier of mud, leaving only a small window to admit air and See also:food. But though in a See also:general way the dictates of hereditary See also:instinct are rigidly observed by birds, in many species a remarkable degree of See also:elasticity is exhibited, or the See also:rule of See also:habit is rudely broken. Thus the See also:falcon, whose See also:ordinary eyry is on the beetling cliff, will for the convenience of procuring See also:prey condescend to lay its eggs on the ground in a See also:marsh, or appropriate the nest of some other bird in a tree. The golden See also:eagle, too, remarkably adapts itself to circumstances, now rearing its young on a precipitous ledge, now on the See also:arm of an See also:ancient monarch of the See also:forest and again on a treeless See also:plain, making a humble See also:home amid grass and herbage. Herons will breed according to circumstances in an open fen, on See also:sea-See also:banks or (as is most usual) on lofty trees. Such changes are easy to understand. The instinct of finding food for the See also:family is predominant, and where most food is there will the feeders be gathered together. This explains, in all likelihood, the associated bands of ospreys or fish-See also:hawks, which in See also:North America breed (or used to breed) in large companies where sustenance is plentiful, though in the Old See also:World the same species See also:brooks not the society of aught but its See also:mate. Birds there are of eminently social predilections. In See also:Europe, apart from sea-fowls—whose congregations are universal and known to all—only the See also:heron, the See also:fieldfare and the See also:rook habitually See also:flock during the breeding season; but in other parts of the world many birds unite in See also:company at that See also:time, and in none possibly is this habit so strongly See also:developed as in the anis of the neotropical region, the republican swallow of North America and the sociable See also:grosbeak of South See also:Africa, which last joins nest to nest until the tree is said to break down under the accumulated See also:weight of the See also:common edifice. In the strongest contrast to these amiable qualities is the parasitic nature of the cuckoos of the Old World and the cow-birds of the New. The egg of the See also:parasite is introduced into the nest of the dupe, and after the necessary incubation by the fond See also:fool of a See also:foster-See also:mother the interloper successfully counterfeits the heirs, who perish miserably, victims of his See also:superior strength. The whole process has been often watched, but the reflective naturalist will pause to ask how such a See also:state of things came about, and there is not much to satisfy his inquiry. Certain it is that some birds whether by See also:mistake or stupidity do not infrequently lay their eggs in the nests of others. It is within the knowledge of many that pheasants' eggs and partridges' eggs are often laid in the same nest, and gulls' eggs have been found in the nests of See also:eider-ducks and See also:vice versa; a See also:redstart and a pied See also:flycatcher will lay their eggs in the same convenient hole—the forest being rather deficient in such See also:accommodation; an See also:owl and a See also:duck will resort to the same nest-See also:box, set up by a scheming woodsman for his own advantage; and the See also:starling, which constantly dispossesses the See also:green See also:woodpecker, sometimes discovers that the rightful See also:heir of the See also:domicile has to be brought up by the intruding See also:tenant. In all such cases it is not possible to say which species is so constituted as to obtain the mastery, but it is not difficult to conceive that in the course of ages that which was driven from its home might thrive through the fostering of its young by the invader, and thus the See also:abandonment of domestic habits and duties might become a See also:direct gain to the evicted householder. . (A. N.) Nests and Coloration.—The correlation between nests and the coloration of the birds has been investigated by A. R. See also:Wallace. Accordingly he divides birds into two See also:main See also:groups, first those in which the sexes are alike and of conspicuous or showy See also:colours, and which nidificate in a covered site; secondly, those in which the males are showy and the females sombre, and which use open sites for their nests. The many exceptions to these generalizations caused J. A. See also:Allen (See also:Bull. Nutt. Orn. See also:Club, 1878) to write an adverse See also:criticism. C. See also:Dixon (H. Seebohm's Hist. Brit. Birds, ii., 1884, introduction) has reviewed the question from Wallace's point of view. He established the following categories. 1. Birds in which the plumage of the male is See also:bright and conspicuous in colour, and that of the female dull and sombre, and which nidificate in open sites. In these very common cases, the female alone incubates, and obviously derives See also:protection from its inconspicuous plumage. 2. Birds in which the plumage of both sexes is showy or brilliant in colour, and which nidificate in open nests. This group forms one of those exceptions which at first sight appear seriously to affect the validity of Wallace's theory. In most of the cases, however, the birds, as, for instance, crows, gulls, herons, are either well able to defend themselves and their nests or, as, for instance, the sandpipers, they seek safety for themselves in See also:flight, relying upon the protective tints of their eggs or young. 3. Birds in which the male is less brilliant than the female, and which nidificate in open nests. Such birds are exceedingly few, e.g. the Phalaropes, the common See also:cassowary, the emu, a carrion See also:hawk (Milvago leucurus) from the See also:Falkland Islands, an Australian tree-creeper (Climacteris erythrops) and an Australian goatsucker (Eurystopodus albigularis). In all these cases the male performs the See also:duty of incubation. The male tinamous do the same, although they do not differ from their mates, but the conspicuously coloured male See also:ostrich takes this duty upon himself during the See also:night. 4. Birds in which both sexes are brightly coloured, and which See also:rear their young in holes or covered nests. For instance, the See also:gaudy coloured rollers, See also:bee-eaters, kingfishers, the See also:hoopoe, hornbills, toucans, parrots, tits, the sheldrake and many others.
5. Birds in which both sexes are dull in colour, and which build covered nests from motives of safety other than concealment. For example, the swifts (Cypselus), the sand-martin (Cotyle riparia), wrens, dippers and owls.
6. Birds in which the female is duller in colour than the male, and which nidificate in covered nests; e.g. the redstart (Ruticilla phoenicura), the pied flycatcher (Muscicapa atricapilla), rock thrushes (Monticola), chats (Saxicola) and See also:robin-chats (Thamnobia), and birds of the genus Malurus. In some of these cases the showy male bird assists in incubation, the See also:kind of nest allowing him to do so with safety.
Similar difficulties beset the generalizations concerning the correlation of the colour of the eggs and the exposed or hidden See also:condition of the nest. The eggs of most birds which breed in holes, or even in covered nests, are See also: The eggs of owls are always white, whether they be deposited in holes on the bare ground or in open nests in a tree. The eggs of the goshawk are white, but those of its small relation, the sparrowhawk, are always blotched, the nest of both being built precisely in the same kind of position, &c. In regard to the almost countless cases of spotted eggs in holes or covered nests, of which so many groups of birds furnish examples either wholly or in part, it has been suggested that the species in question has taken to hiding its eggs in times comparatively See also:recent,.and has not yet, got rid of the ancestral habit of secreting and despositing pigment. Length of Time of Incubation.—Most of the smaller Passeres seem to See also:hatch their young in from 13-15 days. The shortest period, only 10 days, is recorded of the small See also:Zosterops coerulescens; the largest, amounting to about 8 See also:weeks, is that of some of the larger See also:Ratitae, penguins and the See also:condor. The best See also:list, comprising birds of most groups, is that by W. See also:Evans (See also:Ibis, 1891, pp. 52-93; and 1892, pp. 55-58). Speaking broadly, the largest birds lay the largest eggs and require the longest time for incubation, but there are very many exceptions, and only birds of the same group can be compared with each other. The domestic See also:fowl takes 21 days, but the See also:pheasant, though so very nearly allied, takes 2 or 3 days longer, and even the small See also:partridge requires 24 See also:clays. The mallard takes 26, the domestic duck 27, the See also:musk duck 35 days, like most of the swans. The See also:cuckoo, with 13 to 14 days, seems to have adapted itself to the See also:short period of its foster parents. The whole question still affords ample opportunities of experimental investigation and comparison. The condition of the newly hatched birds also varies extremely. The Nidifugae are See also:born with their eyes open, are thinly clothed with neossoptiles of See also:simple structure, leave the nest on the first See also:day and feed themselves. The Nidicolae are born See also:blind, remain a See also:long time in the nest and have to be fed by their parents. Taken as a whole, the Nidifugae comprise most of the phylogenetically older groups; but many of these may include some closely allied members which have reached the developmental level of the Nidicolae: for instance, some Alcidae, the pigeons, Sphenisci, Tubinares, Ciconiae. For detail see BIRDS: See also:Classification. While in the first See also:category the sense See also:organs, tegumentary and locomotory organs are far advanced, these are retarded in the Nidicolae, the development of these structures being shifted onto the postembryonic period. Yet the length of the incubation is by no means always longer in the Nidifu.gae, when compared with equal-sized Nidicolae. For further See also:information the reader may be referred to: A. R. Wallace, " A Theory of Birds' Nests," Journ. of Travel and Nat. Hist., 1868, p. 73, reprinted in his Contributions to the Theory of Natural Selection (See also:London, 187o) ; A. McAldowie, " Observations on the Development and the Decay of the Pigment Layer in Birds' Eggs," Journ. An. Phys. xx., 1886, pp. 225-237; W. Hewitson, Coloured Illustrations of the Eggs of See also:British Birds (3rd ed., London, 1856) ; T. M. See also:Brewer, North See also:American Oology (4to, See also:Washington, 1857) ; A. Lefevre, See also:Atlas See also:des ceufs des oiseaux d'Europe (8vo, See also:Paris, 1845) ; F. W. See also:Baedeker, See also:Die Bier der europiiischen See also:Vogel (fol., See also:Leipzig, 1863); E. Rey, Eier d. Vogel Mittel-See also:Europa's (See also:Gera, 1905); A. See also:Newton, Ootheca Wolleyana (8vo, London, 1864–1907) ; and articles on " Eggs " and " Nidification " in See also:Diet, Birds (London, 1893-1896). (H. F. Additional information and CommentsThere are no comments yet for this article.
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