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But it may be faid, that thefe birds fly in flocks during the* 

 winter, and if they remain here during the fumrner, we mould' 

 fee them equally congregate. 



This circumftance, however, is by no means peculiar to the 

 fieldfare and redwing 5 mofr. of the hard-billed ringing birds do 

 the fame in winter, but feparate in fummer, as it is indeed nece£- 

 fary all birds mould during the time of breeding. 



I mail now confider another argument in favour of migration^ 

 which I do not know hath been ever infifted upon by thofe writers- 

 who have contended for it, and which at firft appearance feems 

 to carry great weight with it. 



There are certain birds which are fuppofed to vifit this ifland 

 only at diftant intervals of years ;■ the Bohemian chatterer and 

 crofs-bill f (for example) once perhaps in twenty. 



The fact, is not difputed, that fuch birds are not commonly 

 obferved in particular fpots from year to, year ; but this may arife 

 from two caufes, either a partial migration within the verge of 

 our ifland, or perhaps more frequently from want of a ready know- 

 ledge of birds on the wing, when they happen- to be feen indeed, 

 but cannot be examined.. 



I never have difputed fuch a partial migration ; and indeed I 

 have received a mofr. irrefragable proof of fuch a flitting, from, 

 Mr. White, whofe accurate obfervations I have before had occa- 

 lion to argue from. 



y This bird varies much in the colour of its plumage, and^is fome~ 

 times red. 



The firft account we have of their being feen, is in the Ph. Tr. abr. 

 Vol. V. p. 33, where Mr. Edward Lhwyd mfpects them- to be Virginia 

 nightingales, from their feathers being red, and had no difficulty of at 

 once fuppofing that they had croffed the Atlantic. 



The. 



