THE MIGRATIONS OF THE ROOK 273 



Jackdaws. On looking out I saw flocks of about one 

 hundred coming in very high from the south-east. A 

 few minutes later I again heard Rooks and Jackdaws, 

 and again saw another flock, also very high, flying 

 northwards ; they were occasionally toying and circling, 

 as one sees them in summer and autumn." 



These, or perhaps we should say some of them, are, 

 no doubt, the return movements to British haunts of 

 the emigrants mentioned as leaving our shores in the 

 autumn. Other individuals, especially the late arrivals, 

 may be on passage to Scandinavia ; the corresponding 

 autumn passage southwards of such foreign immigrants 

 is not obviously recorded in our data, though it probably 

 occurs. 



Spring Eviigration to Central Etirope. — As the 

 movements in the reverse direction were the main ones 

 of the autumn, so are these the most important ones of 

 the spring. 



As the Rooks from Central" Europe were the first to 

 arrive in the autumn, these same birds are the first in 

 the spring to quit our shores, after wintering with us. 

 As early as the second week of February (the loth 

 being the earliest record) these great emigrations from 

 south-eastern England, eastwards across the North Sea 

 set in, reach their maximum during March, and are much 

 in evidence until the middle of April, the 23rd of that 

 month marking their extreme limit in recorded observa- 

 tions. During this prolonged period, vast numbers of 

 emigrants are observed at the lightships between the 

 Humber and the mouth of the Thames (occasionally at 

 the Straits of Dover), passing to the south-east and 

 east during the daytime, from 6 a.m. onwards, and 

 sometimes flying very high, Grey Crows, Daws, Sky- 

 I. s 



