ROOK. 7 



uncommon variety being very pyriform, almost like that 

 of a Snipe. Sometimes they are met with almost spot- 

 less. Average measurement, 17 inch in length, by r2 

 inch in breadth. Incubation, performed by both sexes, 

 lasts from eighteen to twenty days. 



Diagnostic characters : It is impossible to give 

 any reliable character by which the student or collector 

 may be enabled to distinguish the eggs of the Hooded 

 Crow from those of the Carrion Crow and the Rook. 

 The breeding areas cf the two latter species are, however, 

 to a certain extent distinct ; so that the locality, in the 

 absence of more reliable data, should be of some service 

 in their determination. 



Family CORVID.E. Genus CoRVUS. 



ROOK. 



CoRVUS FRUGiLEGUs, Litinceiis. 



Single Brooded. Laying season, March and April. 



British breeding area : The Rook is widely and 

 generally distributed throughout the British Islands, 

 wherever there are trees sufficiently large to support its 

 nest, and the surrounding country is not too barren to 

 furnish it with sustenance. This species is gradually 

 extending its range into many districts, especially in 

 Scotland, where it has followed the planting of trees. 

 More especially has this interesting fact been remarked 

 in the island of Skye, w^iere already there are two 

 extensive colonies, from which pioneers are spreading in 

 various directions with more or less success. As might 

 naturally be inferred, rookeries are more abundant in 



