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THE COMMON SWIFT.
O ordinary observers a Swift appears so much like a Swallow, that the only difference discernible by them is a difference of colour. To the inquiring naturalist, however, a much more important distinction presents itself in the peculiar and remarkable anatomy of the former bird. Not only has it a greater extent of wing, moved by larger and more powerful muscles, but the structure of the foot is curiously adapted for climbing within the narrow crevices which are usually selected as nesting-places. In the Swallow and other Hirundines the toes are long and slender—three in front and one behind birds. In the Swift we find the toes short and stout, and all four directed forwards; the least toe (which should be the hind one) consisting of a single bone, and the other three of only two bones apiece—a peculiar construction, but well adapted for the purposes for which the feet are employed. This singularity of structure has induced naturalists to consider the Swifts (for there are several species) generically distinct from the Swallows; and the former, therefore, are now placed by common consent in the genus Cypse/us, a name adopted from Aristotle, and suggested by Illiger, as indicating the bird's habit of hiding its nest in a hole. The remarks which have been made upon food in the case of the Swallows, apply equally in the case of the Swifts. The latter have so frequently been observed in localities presenting very different species of insects, and sweeping in the summer evenings through the midst of little congregated parties of various kinds, that there is little doubt that the nature of the food
differs very considerably. In corroboration of this it has been shown that anglers have repeatedly captured these birds with artificial trout-flies of very different appearance." Isaak Walton informs us that Swifts were in his time taken in Italy with rod and line; and, according to Washington Irving, one of the sports of the Alhambra was angling for swallows from its lofty towers.” There are several species of Swifts distributed throughout the world, but only two visit the British Islands, and of these one is but a rare and accidental visitant. The Common Swift is the last of the Hirundines to arrive in this country, and the first to leave it. Its habits are very different from those of the Swallows. As a rule it makes no nest, but only lines a hole, into which it creeps; it lays but two eggs (rarely three), instead of five or six like the Swallows; it rears but one brood in the summer, instead of two, or even three, as Swallows often do. The late Mr. J.
* Thompson, “Nat. Hist. Ireland” (Birds), i. p. 377. * Irving, “Tales of the Alhambra.”
D. Salmon described some nests of the Swift which he found at Stoke Ferry, Norfolk, and which were composed of bits of straw and dry grass, “closely interwoven and held firmly together by an adhesive substance very much resembling glue, and so disposed round the inner edge of the nest as to hold the straws in their places; the whole forming quite a cup of an oval shape, of about four inches in length, not very deep.” I have often observed the straw and dry grass, with the addition of feathers, but never noticed the “adhesive substance.” Gilbert White thought that the Swift paired on the wing. They may do so occasionally; but, from what I have observed, I feel sure that they pair much oftener in the hole which has been selected to nest in. Although usually preferring lofty towers and church turrets, the Swift frequently nests under eaves at a comparatively short distance from the
ground; and I have had excellent opportunities for some years past of observing Swifts during the breeding season under the eaves of some old cottages in Sussex and Middlesex. By means of a short ladder I have been enabled to inspect many nests both before and after the young were hatched; and, out of a score or more examined, seldom more than one contained three eggs. Sometimes I observed that Sparrows were ejected and their nests appropriated, amidst much remonstrance and screaming; but, as a rule, I have found that Swifts, having once reared their young safely in a new locality, will return to the same hole year after year. Birds have been marked by having their claws cut, and, on being set at liberty, were caught the following year in the holes from which they had first been taken. Unlike most insectivorous birds, which bring but a single insect (or at most two or three) to the nest at a time, the Swift visits its young less frequently in the day, but brings a large store at each visit. The mouth is often so crammed with small
1 “Mag. Nat. Hist.” 1834, vol. vii. p. 462.