ORDER OF MIGRATION ACCORDING TO AGE AND SEX 109 



Altliough on the Continent, with its forests and mountains, investi- 

 gation of migration phenomena of this kind must be incomparably 

 more ditiicult, more especially as these become complicated with 

 every degree of latitude further south, yet careful and critical 

 observations should enable us to recognise them without difficulty, 

 in the case of species ditiering so markedly in the colours of their 

 early and adult plumages as Starlings, Blackbirds, Redstarts, Chats, 

 and many others. 



Thus the number of young birds of species which, besides 

 breeding in northern latitudes, do so also in Germany and England, 

 must, in these countries, of necessity undergo a very considerable 

 increase at the beginning of the migi-ation. Even if the young 

 birds bred in these countries had already left before the arrival of 

 the new immigrants, the quantity of the latter would still be far in 

 excess of the former, no matter whether it was made up of indivi- 

 duals from the north or from the east. My old friend and opposite 

 neighbour on the east coast of England, John Cordeaux, has indeed 

 foimd this view fully confirmed in the case of the Chats and Red- 

 starts. 



Careful observation will probably everywhere bring into recogni- 

 tion the original character of the autumn migration, in the more 

 numerous arrivals of young birds at its beginning, and the pre- 

 dominance of old individuals at its close. Or, again, this character 

 will express itself, as, for instance, in central and southern Ger- 

 many, by the stay of the old birds of many species within the 

 circuit of their breeding area, and the departure of birds of the 

 same species bred in those districts, and the passage of those young 

 birds of the species which have been bred in regions further north. 



A similar difference in the time of migration of old and young 

 birds has been noted in regard to the Blackbird within Xaumann's 

 area of observation. In regard to this species the great ornithologist 

 says (vol. ii. p. 331), that of those individuals which breed in pine 

 woods, containing juniper bushes, the old do not depart at the end 

 of the breeding season, but that those which breed in leafy woods, 

 in the winter leave for localities which afford them suitable nourish- 

 ment; and that the young of all, on the other hand, no matter 

 under what surroundings they are bred, depart in September and 

 October; that the old birds were already back at their breeding 

 stations as early as the beginning of March, whereas the young 

 birds did not return until the end of the month. 



However, in these latitudes, among those species in which the 

 old birds migrate like the rest, the first to leave unnoticed will 

 be the 3'oung individuals which have been bred on the spot, their 

 place being taken by other young birds which have been bred in 



