NA TURA L HIS TORY OF SELBORNE. 175 



LETTER XXI. 



TO THE SAME. 



SELBORNE, Sept. 2%th, 1774. 



DEAR SIR, As the swift or black-martin is the largest of the 

 British hir undines, so it is undoubtedly the latest comer. For I 

 remember but one instance of its appearing before the last week in 

 April ; and in some of our late frosty, harsh springs, it has not been 

 seen till the beginning of May. This species usually arrives in 

 pairs. 



The swift, like the sand-martin, is very defective in architecture, 

 making no crust, or shell, for its nest ; but forming it of dry grasses 

 and feathers, very rudely and in artificially put together. With all 

 my attention to these birds, I have never been able once to discover 

 one in the act of collecting or carrying in materials ; so that I have 

 suspected (since their nests are exactly the same) that they some- 

 times usurp upon the house-sparrows, and expel them, as sparrows 

 do the house and sand-martin ; well remembering that I have seen 

 them squabbling together at the entrance of their holes, and the 

 sparrows up in arms, and much disconcerted at these intruders. 

 And yet I am assured, by a nice observer in such matters, that they 

 do collect feathers for their nests in Andalusia, and that he has shot 

 them with such materials in their mouths.* 



Swifts, like sand-martins, carry on the business of nidification 

 quite in the dark, in crannies of castles, and towers, and steeples, 

 and upon the tops of the walls of churches under the roof ; and 

 therefore cannot be so narrowly watched as those species that build 

 more openly ; but, from what I could ever observe, they begin nest- 

 ing about the middle of May ; and I have remarked, from eggs taken, 

 that they have sat hard by the ninth of June. In general they haunt 



* The swift collects materials for its nest same as the swallows ; it is, however, a very 

 simple structure, and the opening to it is often so narrow that it is an exertion for the 

 parent bird to get in. White, towards the conclusion of this letter, seems to be aware of 

 only another swift the white-bellied ; but there are many now known, and as proposed in the 

 same paragraph we allude to, the first upon p. 180, the genus Cypselus has been formed, 

 and is universally recognised for them. The description of the swift in this letter is 

 altogether excellent, and alone would have shown Mr, White to have been a most close 

 and accurate observer. The white-bellied swift has been taken in Great Britain. 



