HISTORY OF THE SWIFT. 175 



gler invariably withdraws by the twentieth, while their conge- 

 ners, all of them, stay till the beginning of October ; many of 

 them all through that month, and some occasionally to the be- 

 ginning of November.* This early retreat is mysterious and won- 

 derful, since that time is often the sweetest season in the year. 

 But, what is more extraordinary, they begin to retire still earlier 

 in the most southerly parts of Andalusia, where they can be no 

 ways influenced by any defect of heat ; or, as one might suppose, 

 defect of food. Are they regulated in their motions with us by 

 a failure of food, or by a propensity to moulting, or by a disposi- 

 tion to rest after so rapid a life, or by what ? This is one of 

 those incidents in natural history that not only baffles our 

 searches, but almost eludes our guesses 1 



These hirundines never perch on trees or roofs, and so never 

 congregate with their congeners. They are fearless while haunt- 

 ing their nesting places, and are not to be scared with a gun ; 

 and are often beaten down with poles and cudgels as they stoop 

 to go under the eaves. Swifts are much infested with those 

 pests to the genus called Uppoboscce hirundinis; and often wriggle 

 and scratch themselves, in their flight, to get rid of that clinging 

 annoyance. 



Swifts are no songsters, and have only one harsh screaming 

 note ; yet there are ears to which it is not displeasing, from an 

 agreeable association of ideas, since that note never occurs but in 

 the most lovely summer weather. 



They never settle on the ground but through accident ; and 

 when down can hardly rise, on account of the shortness of their 

 legs and the length of their wings ; neither can they walk, but 

 only crawl; but they have a strong grasp with their feet, by 

 which they cling to walls. Their bodies being flat they can 

 enter a very narrow crevice ; and where they cannot pass on their 

 bellies they will turn up edgewise. 



The particular formation of the foot discriminates the swift 

 from all the British hirundines ; and indeed from all other known 

 birds, the hirundo melba, or great white-bellied swift of Gibraltar, 



* A correspondent of the Magazine of Natural History relates one instance of a swift being 

 noticed in Perthshire so late as Nov. 8 ; and I have known them once or twice to occur in Sep- 

 tember. So powerful is the migrative impulse in these birds that it is not a very rare occurrence 

 for them to leave a young brood of half-fledged nestlings to perish a fact which has also been 

 noticed in others of the swallow tribe. A remarkable instance, however, to the contrary is stated 

 in the periodical already mentioned, in which a single swallow was observed to stay for some time 

 after the departure of its fellows, to attend upon a full grown nestling, the foot of which had been 

 inextricably entangled iu the nest. ED. 



