BIRDS 137 



almost always to be found in its company. It is considerably larger than 

 the Jackdaw, and is distinguished from the Crow by the white skin round the 

 base of the bill. (The young Rook, however, has the base feathered up to the 

 second moult.) The species has a remarkable interest in point of view of its 

 curious migrations, flocks of birds coming and going from Europe and the 

 North in September to November, and again in February to April, returning 

 in due course to their breeding lands. Our own native Rooks also migrate 

 to Ireland and back. 



The Rook nests in colonies, as is well known, beginning its courtship in 

 February, and repairing its nest in the middle of March. It appears to pair 

 for life. Though one is accustomed to its familiar " Caw," it has many other 

 notes and tones. The eggs, three to five, are greenish, with brown markings. 

 The Rook is credited with great sagacity and cunning ; but, amongst other 

 popular statements, the one that it posts a sentinel when at its meals in the 

 farmer's fields lacks proof. 



It is, however, a valuable friend to the farmer, its food consisting of worms, 

 insects, slugs, etc. 



Scoter (BLACK DUCK). This member of the "Diving Ducks" is at once 

 distinguished by the complete black plumage of the drake (the duck being a 

 sooty brown, with greyish cheeks and whitish throat), and the peculiar bill, 

 black and yellow, with a curious excrescence at the base. [The Velvet Scoter, 

 sometimes found in its company, has a white patch on the wing of both sexes. 

 It is a rarer winter visitor.] 



The Scoter is very restricted in its breeding area a few places in the 

 North of Scotland, especially Caithness and Sutherland but appears some- 

 times in large flocks, in the winter, round our coasts. 



The nest is usually in water-logged moorland, under a bush or among 

 heather, in a depression scantily lined with bents, dead leaves, etc., and plenty 

 of down. The eggs are light buff or cream in colour, large, and pointed oval. 



In winter the Scoter is entirely a marine bird, feeding on mussels and 

 other molluscs. The usual call is the drake's " Kr-kr-kr," answered by the 

 duck's " Re-re-re." 



Shag (GREEN CORMORANT see notes on CORMORANT). Is distinguished 

 from the Cormorant by its smaller size, twelve tail feathers, and the greenish 

 tinge in its black plumage. In the spring both sexes have a recurved crest 

 on the head, but this is soon lost. It breeds locally, on rocky coasts, but is 

 absent from the South-east and East Coasts from the Isle of Wight to 

 Northumberland ; more generally distributed in winter. 



It is entirely a marine bird. Its call is " Gau-gau " and " Crew-a-oop." 

 It prefers sea caves to nest in, or some rocky cover (differing from the Cor- 

 morant in this respect). Seaweed and coarse vegetation form the material 

 of the nest. Three to five eggs are laid, blue, with a chalky incrustation, 

 like but smaller than the Cormorant's. It feeds on fish. 



Shelduck, recognizable by its size and patched plumage : head and neck 



