52 THE NIGHT-SOARING OF THE SWIFTS. 



best part of your life, and have read Gilbert White's 

 monograph on the swift in his Natural History of Selborne, 

 you will know that the eggs two or sometimes three take 

 19 to 21 days to hatch, and that the young, which are blind 

 for nine days, take six weeks to reach maturity. That they 

 remain in the nest, never leaving it till they fly to Africa 

 probably without resting. That these and all other summer 

 migrants come here only to breed, and leave as soon as the 

 young are ready to fly ; and that, unlike the swallows, the 

 swifts have only one brood. That the hen alone tends the 

 young. That its nest is bound together by the glutinous 

 saliva of the swift. And doubtless, if you have had my 

 opportunities, you have, when you realised the difficulty they 

 have in procuring materials in the air, scattered feathers 

 from the soundholes and watched them race for these, and 

 noted how, though not a swift was in sight at first, soon the 

 air was full of the dark forms capturing feather after feather 

 till they seemed to have long white moustaches streaming 

 out on each side. And when you have been watching up 

 amongst the bells in the church tower, and taking notes of 

 dates day after day, you may have been set back a whole 

 year by a wretched mouse killing the bird you were watching 

 to ascertain its rate of growth. You will know what beautiful 

 glossy birds the young ones are, with their quill feathers 

 edged with light and with their pink feet. You will know 

 that the swift can fast for a long time, but that cold weather 

 numbs and eventually kills it. That its food consists ex- 

 clusively of winged insects, which it cannot take except in 

 the air, as it is too highly specialised to be able to pick a fly 

 off a window. You will know what merry and playful birds 

 they are, and that they have been evolved for a life in the air. 



I thought the members might like to be reminded of a few 

 of the interesting facts they know about the swifts before 

 coming to the point of this paper The Night-soaring of the 

 Swifts. 



If you will watch the swifts at sunset on a fine evening 

 you will see them all gather together and fly about in all 



