202 NATURAL HISTOEJ 



\ 



LETTER XXI. 



TO THE HONOURABLE DAINES BARRINGTON. 



SELBORNE, Sept. 28, 1774. 



S the swift or black martin is the largest of 

 the British Hirundines, so is it 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 archi- 

 tecture, making no crust or shell for its nest ; but forming 

 it of dry grasses and feathers, very rudely and inartificially 

 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 sometimes 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 mate- 

 rials in their mouths. 



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

 cation 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 nesting about the middle of 

 May; and I have remarked, from eggs taken, that they have 

 sat hard by the 9th of June. In general they haunt tall 

 buildings, churches, and steeples, and breed only in such : yet 



