THE ROOK. 15 



and Crows in pairs, but Crows are sometimes seen in company 

 and Rooks singly. In flight difficult to distinguish. Note, 

 raucous croak "varrock," hardly differs from Hooded Crow's, 

 but cannot be mistaken for any note of Rook. 



BREEDING-HABITS. Nests chiefly in trees, but in hills of Wales 

 often in small bushes on hill-sides and on ledges of cliffs on coast ; 

 once on low stone-wall. Nest. Closely resembles Hooded Crow's, 

 sometimes very conspicuous and at times cleverly hidden ; built 

 of sticks and twigs, earth, moss, etc., lined hair and wool. 

 Eggs. Usually 4-5, rarely 6 ; like Hooded Crow's, but average 

 rather paler and not so green. One egg of clutch often sparsely 

 marked ; blue, unmarked eggs rare ; some very heavily marked 

 at end. Average size of 100 eggs 43.5 X 30.1 mm., larger than 

 Hooded Crow's or Rook's. Breeding-season. Begins early April. 

 Incubation. Lasts 18-19 days ; both sexes said to incubate, but 

 more evidence is desirable in view of E. Selous's observations. 

 Eggs incubated as laid. One brood. Fledging-period. 33-34 

 days (S. E. Brock). 



FOOD. Very varied, including carrion, small mammals (rabbits, 

 mice), wounded and small birds, eggs of many birds, frogs, toads, 

 mollusca, insects (especially beetles), worms, and grain. 



DISTRIBUTION. England and Wales. Resident and common, 

 but somewhat local. Scotland. Resident. On east side common 

 as far north as Perth, not rare in north of Moray area, and 

 occasionally nests east Sutherland ; on west side common parts of 

 Clyde district, but scarce resident Skye and very scarce north-west 

 Highlands ; occasional visitor Orkneys, Shetlands, and Fair Isle, 

 once Outer Hebrides (Flannans). Where overlapping range of 

 C. c. comix, frequently interbreeds. Ireland. Very rare. Said 

 to have bred Mayo, 1890. 



MIGRATIONS. British Isles. Appears to arrive with Rooks east 

 coast Great Britain from central Europe between Sept. and Nov., 

 and to return between mid-Feb. and mid-April, but very few of 

 such migrants appear to have been properly identified. 



DISTRIBUTION. Abroad. Western Europe generally, in Germany 

 roughly to the Elbe, and throughout the Alps to Bohemia. An 

 allied form in north-east Asia. Interbreeds with C. comix in 

 Germany and Siberia where ranges overlap. 



CORVUS FRUGILEGUS 



4. Corvus frugilegus frugilegus L. THE ROOK. 



CORVTTS FRUGILEGUS Linnaeus, Syst. Nat., ed. x, i, p. 103 (1758 



Europe. Restricted typical locality : Sweden). 



Corvus frugilegus Linnaeus, Yarrell, n, p. 289 ; Saunders, p. 247. 



