NA TURAL HISTOR Y OF SELBORNE. 253 



LETTER LII. 



TO THE SAME. 



SELBORNE, Sept. gth, 1781. 



I HAVE just met with a circumstance respecting swifts, which 

 furnishes an exception to the whole tenor of my observations ever 

 since I have bestowed any attention on that species of hirundines. 

 Our swifts, in general, withdrew this year about the first day of 

 August, all save one pair, which in two or three days was reduced 

 to a single bird. The perseverance of this individual made me 

 suspect that the strongest of motives, that of an attachment to her 

 young, could alone occasion so late a stay. I watched therefore 

 till the 24th of August, and then discovered that, under the eaves 

 of the church, she attended upon two young, which were fledgedj 

 and now put out their white chins from a crevice. These re- 

 mained till the twenty-seventh, looking more alert every day, and 

 seeming to long to be on the wing. After this day they were 

 missing at once ; nor could I ever observe them with their dam 

 coursing round the church in the act of learning to fly, as the first 

 broods evidently do. On the thirty-first I caused the eaves to be 

 searched, but we found in the nest only two callow, dead, stinking 

 swifts, on which a second nest had been formed. This double 

 nest was full of the black shining cases of the hippoboscce 

 hirundinis. 



The following remarks on this unusual incident are obvious. The 

 first is, that though it may be disagreeable to swifts to remain 

 beyond the beginning of August, yet that they can subsist longer 

 is undeniable. The second is. that this uncommon event, as it was 

 owing to the loss of the first brood, so it corroborates my former 

 remark, that swifts breed regularly but once ; since, was the con- 

 trary the case, the occurrence above could neither be new nor 

 rare. 



P.S. One swift was seen at Lyndon, in the county of Rutland, in 

 1782, so late as the third of September. 



