230 NATURAL HISTORY 



LETTER IX. 



TO THE SAME. 

 DEAR SIR, FYFIELD, near ANDOVER, Feb. 12, 1771. 



You are, I know, no great friend to migration ; and the 

 well attested accounts from various parts of the king- 

 dom seem to justify you in your suspicions, that at 

 least many of the swallow kind do not leave us in the 

 winter, but lay themselves up like insects and bats, in 

 a torpid state, and slumber away the more uncomfort- 

 able months till the return of the sun and fine weather 

 awakens them. 



But then we must not, I think, deny migration in 

 general; because migration certainly does subsist in 

 some places, as my brother in Andalusia has fully 

 informed me. Of the motions of these birds he has 

 ocular demonstration, for many weeks together, both 

 spring and fall : during which periods myriads of the 

 swallow kind traverse the Straits from north to south, 

 and from south to north, according to the season. And 

 these vast migrations consist not only of Hirundines, 

 but of bee-birds, hoopoes, Oro pendolos, or golden 

 thrushes, &c. &c. and also of many of our soft-billed 

 summer birds of passage ; and, moreover, of birds which 

 never leave us, such as all the various sorts of hawks 

 and kites. Old Belon, two hundred years ago, gives 

 a curious account of the incredible armies of hawks and 

 kites which he saw in the spring time traversing the 

 Thracian Bosphorus from Asia to Europe. Besides 

 the above-mentioned, he remarks that the procession is 

 swelled by whole troops of eagles and vultures. 



Now, it is no wonder that birds residing in Africa 

 should retreat before the sun as it advances, and retire 

 to milder regions, and especially birds of prey, whose 

 blood being heated with hot animal food, are more 



