The Natural History of Selborne 193 



But then we must not, I think, deny migration in general ; be- 

 cause 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 pears ago, gives a curious account of the incredible armies 

 of hawks and kites which he saw in the springtime 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. 1 



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, &c. ; because, if we reflect, a 

 bird may travel from England to the Equator without launching out 

 and exposing itself to boundless seas, and that by crossing the water 

 at Dover, and again at Gibraltar. And I with the more confidence 

 advance this obvious remark, because my brother has always found 

 that some of his birds, and particularly the swallow kind, are very 

 sparing of their pains in crossing the Mediterranean ; for when 

 arrived at Gibraltar they do not 



1 It is curious to see how often and how persistently our great naturalist returns 

 to this question of migration. ED. 



