592 



PERCHING BIRDS 



from crows by the steely blue reflections on the plumage of the upper- 

 parts, and the more slenderly formed beak. The same features serve to 

 distinguish young rooks from young crows ; a further point of difference 

 being that in the former the interior of the mouth is slate-coloured. 



The range of the rook comprises the greater part of northern and 

 central Europe, extending in Scandinavia as high as the Arctic Circle, 

 but gradually declining as we proceed eastwards, where in Asia it 

 extends as far as Turkestan and the valley of the Irtish, and in winter 

 includes the north-western provinces of India, Persia, and Asia Minor. 



At the same season rooks 



resort to the Mediterranean 



countries farther west. 



- ->-_ Despite the enormous 



numbers in which rooks 

 are to be found through- 

 out almost the whole of 

 the British Isles, large 

 arrivals annually make 

 their appearance for the 

 winter from the east. More- 

 over, the species seems to 

 be gradually extending its 

 range, having of late years 

 taken to nesting in the 

 Outer Hebrides, although 



MEAD OK YOING KOOK. 



it docs not yet appear to 

 have done so in Shetland. 

 Gregarious habits are at all times essentially characteristic of the 

 species, which is so thoroughly well known that brief notes in regard to 

 its habits will suffice. " Rookery " has now become a term for all large 

 breeding colonies of animals — human or otherwise ; and it is stated 

 that these birds will never build in trees which are not thoroughly 

 sound and safe. It has been noticed that when a pair of rooks 

 attempts to build apart from the rest in a tree previously unoccupied, 

 the other members of the colony frequently set to work to destroy the 

 new settlement. In 1905 an event of this nature took place in the 

 churchyard of Christ Church, .Skipton. In this instance a pair of rooks 

 had built in a tree overhanging a street, and the female was incubating 

 her eggs. While thus engaged she was attacked b>' the other rooks, 

 which pecked her to death, throwing the body, together with the broken 

 eggs and the ruined nest, to the ground. 



