258 THE NATURAL HISTORY [LETT. 



LETTEK XCVI. 



TO THE HONOURABLE DAINES BARRINQTOX. 



I HAVE just met with a circumstance respecting swifts which 

 furnishes an exception to the whole tenor of niy observations 

 ever since I have bestowed any attention on that species of 

 Mrundines. 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 in- 

 dividual 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 fledged, and now put out their white chins from 

 a crevice. These remained till the 27th, 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 31st 

 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 sub- 

 sist longer is undeniable. The second is, that this uncommon 

 event, as it was owing to the loss of the first brood, so it corro- 

 borates my former remark, that swifts breed regularly but once ; 

 .since, was the contrary the case, the occurrence above could 

 neither be new nor rare. 



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

 in 1780, so late as the 3rd of September. 



SELBORNE, Sept. 9, 1781. 



