206 SWIFTS. 



their leisure, and do not attend on their nests for 

 hours together. 



Sometimes they pursue and strike at hawks that 

 come in their way, but not with that vehemence and 

 fury that swallows express on the same occasion. 

 They are out all daylong on wet days, feeding about, 

 and disregarding still rain ; from whence two things 

 may be gathered, first, that many insects abide high 

 in the air, even in rain ; and next, that the feathers 

 of these birds must be well preened to resist so much 

 wet. Windy, and particularly windy weather with 

 heavy showers, they dislike, and on such days with- 

 draw, and are scarcely ever seen. 



There is a circumstance respecting the colour of 

 swifts, which seems not to be unworthy our attention. 

 When they arrive in the spring, they are all over of a 

 glossy dark soot colour, except their chins, which are 

 white ; but, by being all day long in the sun and air, 

 they become quite weather-beaten and bleached be- 

 fore they depart, and yet they return glossy again in 

 the spring. Now, if they pursue the sun into lower 

 latitudes, as some suppose, in order to enjoy a perpe- 

 tual summer, why do they not return bleached ? Do 

 they not rather, perhaps, retire to rest for a season, 

 and at that juncture moult and change their feathers, 

 since all other birds are known to moult soon after 

 the season of breeding 1 



Swifts are very anomalous in many particulars, 

 dissenting from all their congeners, not only in the 

 number of their young, but in breeding but once in 

 a summer ; whereas all the other British hirundines 

 breed invariably twice. It is past all doubt that 

 swifts can breed but once, since they withdraw in a 

 short time after the flight of their young, and some 

 time before their congeners bring out their second 

 broods. We may here remark, that, as swifts breed 

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