358 BRITISH BIRDS. [vol. vi. 



or both, but it would be an easy matter and an interesting 

 one to investigate and decide. 



When however we turn to the Mediterranean region 

 where the Continental races of Robin, Hedge-Sparrow, 

 and Song-Thrush are only known in winter-time, we find 

 the two last named silent and skulking, and the Robin 

 (whose breeding-range by the way is not very far to the 

 northward) practically the only singing representative 

 among the winter- visitors, and even then it gives but a 

 poor performance compared with that in more northern 

 latitudes. 



The Sky-Lark which commences to sing regularly in 

 January in England is another silent Mediterranean 

 winterer, and in general we find that song is almost 

 absent from these parts in winter-time, when the majority 

 numerically* of the singing Passeres are represented by 

 " winter-visitors " only. 



Exactly the same state of affairs occurs in the Lower 

 Yangtze Basin, a region that zoogeographically has 

 a somewhat analogous position to the Mediterranean, 

 and if we go to zones still further south and more 

 remote from the breeding-range of these species, 

 we find the same condition still more accentuated ; 

 at least this is my own experience, and is confirmed 

 so far as I can find by recorded information on the 

 subject. 



That no birds sing when actually on migration is, I 

 believe, generally accepted. Such is certainly my own 

 experience. All this seems to me very suggestive of a 

 connexion between " winter-song " and " migratory 

 movement," and as if it were not very far from the 

 truth to say that winter-songsters are those individuals 

 which are sedentary or perform comparatively short 

 migration journeys. In other words, that " winter-song " 

 and " migratory-movement " are in inverse ratio to one 

 another in the individual. 



* In number of species the " resident " and " winter-visitors " 

 are about equal. 



