THE SWIFT 



THE SWIFT 

 [F. B. KIKKMAN] 



Formerly the Swifts used to be classed with the Swallows, to 

 which in external appearance and mode of life they are not unlike. 

 Fundamental differences in structure have made it necessary to 

 separate the two groups, and not only BO, but to place the Swifts 

 quite outside the great Order (Piiwri/onw*) to which the Swallows 

 belong. The Swifts now form a group apart (Cypm-li) with the 

 Humming-birds, to which, though not very closely related, they have 

 important resemblances, notably the great length of the wing-l>ones, 

 the deep unnotched keel, and the absence of the intestinal blind-sacs. 

 From the Swallows and other Passerine birds they differ in what is one 

 of the chief characteristics of the Pasvere*, the structure of the foot 

 The Swifts have four toes, all directed forward, none of which can be 

 bent independently of the others. The Passeren have four toes, but 

 one of these is directed backwards, and can be moved independently 

 of the others. Again, the great majority, if not all, Passerine species 

 have the power of song, though some, like the raven, make poor use 

 of it 1 The Swifts have no song, unless this term be applied 

 to its screaming note. They differ further from the Paxnerex in the 

 distribution of their feather tracts and other particulars. But as they 

 are alone in resembling the Passeres in the form of the skull, 9 and 

 are similar to them in other respects, they are placed with them on 

 the same great branch of the avian genealogical tree. 8 



There are numerous species of Swifts, but three only are to be 

 found on the list of British birds, and of these the Alpine-swift is a 



1 See TO!, i. p. 12. 



* With differences. See Beddard, Structure and CUiurification, p. 228. 



' For the systematic position of the swifts, sec Beddard, Structure and C'laiunficatwn, 

 P 224 (and works there quoted); W. P. Pycraft, UMory of Birds, p. 57; Xoulogimt, 1880. 01 

 (W. K. Parker); Ibid.. 1877. 217 (A. II. Garrod). 



