Online Encyclopedia

Search over 40,000 articles from the original, classic Encyclopedia Britannica, 11th Edition.

SWIFT

Online Encyclopedia
Originally appearing in Volume V26, Page 231 of the 1911 Encyclopedia Britannica.
» Make a correction to this article.
» Add information or comments to this article.
Spread the word: del.icio.us del.icio.us it!

SWIFT , a See also:

bird so called from the extreme See also:speed of its See also:flight, which apparently exceeds that of any other See also:British See also:species, the Hirundo apus of See also:Linnaeus and Cypselus apus or murarius of See also:modern ornithologists. Swifts were formerly associated with swallows (q.v.) in See also:classification, but whilst the latter are true Passeres, it is now established that swifts are Coraciiform birds (see BIRDS) and the sub-See also:order Cypseli has been formed to include them and their nearest See also:allies, the humming-birds. The four toes are all directed forwards, whereas in the Passeres the hallux is directed backwards and by opposing the other three makes the See also:foot a grasping See also:organ. In the swifts, moreover, the See also:middle and See also:outer digits have only three See also:joints and the metatarsi and even the toes may be feathered. Swifts are divided into three sub-families: Macropteryginae, the true swifts, of tropical See also:Asia, which See also:form a See also:nest gummed by saliva to branches of trees; Chaeturinae, See also:building in rocks or houses, and with an almost See also:world-wide range: it includes Chaetura palagica, the " See also:chimney-See also:swallow " of the See also:United States, Collocalia fuciphaga which obtained its specific name from the erroneous See also:idea that its edible nests were formed by partly digested seaweed; Cypselinae, also world-wide and containing Cypselus apus, the See also:common See also:European swift. All the swifts are migratory. Well known as a summer visitor throughout the greater See also:part of See also:Europe, the swift is one of the latest to return from See also:Africa, and its stay in the See also:country of its See also:birth is of the shortest, for it generally disappears from See also:England very See also:early in See also:August, though occasionally to be seen for even two months later. The swift commonly chooses its nesting-See also:place in holes under the See also:eaves of buildings, but a crevice in the See also:face of a See also:quarry, or even a hollow See also:tree, will serve it with the See also:accommodation it requires. This, indeed, is not much, since every natural See also:function except See also:sleep, oviposition and See also:incubation, is performed on the wing, and the easy evolutions of this bird in the See also:air, where it remains for See also:hours together, are the admiration of all who See also:witness them. Though considerably larger than a swallow, it can be recognized at a distance less by its See also:size than by its See also:peculiar shape. The See also:head scarcely projects from the anterior outline of the pointed wings, which form an almost continuous See also:curve, at right angles to which extend the See also:body and tail, resembling the handle of the crescentic cutting-See also:knife used in several trades, while the wings represent the blade. The mode of flight of the two birds is also unlike, that of the swift being much more steady, and, rapid as it is, ordinarily See also:free from jerks.

The whole plumage, except a greyish See also:

white patch under the See also:chin, is a sooty See also:black, but glossy above. Though its actual breeding-places are by no means numerous, its extraordinary speed and discursive habits make the swift widely distributed; and throughout England scarcely a summer's See also:day passes without its being seen in most places. A larger species, C. See also:melba or C. alpinus, with the See also:lower parts dusky white, which has its See also:home in many of the mountainous parts of central and See also:southern Europe, has several times been observed in See also:Britain, and two examples of a species of a very distinct genus Chaetura, which has its home in See also:northern Asia, but regularly emigrates thence to See also:Australia, have been obtained in England (Prot. Zool. See also:Soc., 188o, p. 1). Among other peculiarities the swifts, as See also:long ago described (probably from See also:John See also:Hunter's notes) by See also:Sir E. Home (Phil. Trans. 1817, pp. 332 et seq., pl. xvi.), are remarkable for the development of their salivary glands, the secretions of which serve in most species to See also:glue together the materials of which the nests are composed, and in the species of the genus Collocalia form almost the whole substance of the structure. These are the " edible " nests so eagerly sought by See also:Chinese epicures as an ingredient for soup.

These remarkable nests consist essentially of mucus, secreted by the salivary glands above mentioned, which dries and looks like See also:

isinglass. Their marketable value depends on their See also:colour and purity, for they are often intermixed with feathers and other See also:foreign substances. The swifts that construct these " edible " nests form a genus Collocalia, with many species; but they inhabit chiefly the islands of the See also:Indian Ocean from the See also:north of See also:Madagascar eastward, as well as many of the tropical islands of the Pacific so far as the See also:Marquesas—one species occurring in the See also:hill-country of See also:India. They breed in caves, to which they resort in See also:great See also:numbers, and occupy them jointly and yet alternately with bats—the mammals being the lodgers by day and the birds by See also:night.

End of Article: SWIFT

Additional information and Comments

There are no comments yet for this article.
» Add information or comments to this article.
Please link directly to this article:
Highlight the code below, right click, and select "copy." Then paste it into your website, email, or other HTML.
Site content, images, and layout Copyright © 2006 - Net Industries, worldwide.
Do not copy, download, transfer, or otherwise replicate the site content in whole or in part.

Links to articles and home page are always encouraged.

[back]
SWEYN I 		[next]
SWIFT, JONATHAN (1667—1745)

Site © 2006 - Net Industries