134 NATURAL HISTORY OP SELBORNE. 



state, and slumber away the more uncomfortable mon' 

 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 con- 

 sist not only of hirundines but of bee-birds, hoopoes, Oro 

 pendolos, or golden thrushes, etc., etc., 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 impatient of a sultry 

 climate ; but then I cannot help wondering why kites and 

 hawks, and such hardy birds as are known to defy all the 

 severity of England, and even of Sweden and all north 

 Europe, should want to migrate from the south of Europe, 

 and be dissatisfied with the winters of Andalusia. 



It does not appear to me that much stress may be laid 

 on the difficulty and hazard that birds must run in their 

 migrations, by reason of vast oceans, cross winds, etc. ; 

 because, if we reflect, a bird may travel from England to 



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