14 



greater part of Europe east of the longitude of Heligoland, extend- 

 ing as far north as the limits of forest growth, and about as far 

 south as lat. 48° ; colonies also exist to the west and in north- 

 eastern Africa; but it is not necessary to take the latter into 

 account at the present juncture. Writing on the Hooded Crow, 

 Seebohm remarks : — " Though the area of its distribution is 

 intersected by the narrow belt of Carrion Crows, which connects 

 the East Siberian colony with the Turkestan colony, and the 

 latter with the west European colony, it cannot be said to be 

 discontinuous. On the continent the Hooded Crow is found 

 throughout Europe east of long. 10°, and in Asia extends north 

 of Turkestan as far as the valley of the Yenesay. . . . The 

 Scandinavian birds migrate to Holland, Belgium, and Northern 

 France, and even to England, in winter; and many of the 

 Siberian birds, together with hybrids of every degree, winter in 

 Turkestan." Amongst the millions of this species which pass 

 Heligoland every year, many of which, in Herr Gatke's view, are 

 derived from regions in the far east, he has not detected any of 

 these hybrids alluded to by Seebohm. Now what a remarkable 

 fact it would be if the individuals breeding beyond the region 

 where the former are produced, when migrating to the west, were 

 not frequently accompanied by many examples of the latter. 

 In the absence of these hybrids, it appears very unlikely that 

 any of the great flights passing from Heligoland are really 

 derived from a breeding area in far Eastern Asia. It will be 

 observed that Herr Gatke assigns the Lena as the limit of this 

 breeding area. On the other hand, most authorities mention the 

 valley of the Yenesay. 



Even if these hybrids were unnoticed by reason of their not 

 passing directly over the island, they would hardly escape detec- 

 tion on their landing on the eastern coast of England, which 

 Herr Gatke informs us is the next destination of the vast flights 

 which pass his observatory. 



What numbers of so voracious a species as the Hooded Crow 

 any given area could support is very difficult to say. But if we 

 consider the great quantities of Rooks which find a thriving 

 living in a limited district like the Midland counties of England 

 — where every village has its rookery — we may perhaps not deem 



