6 THE CROW FAMILY 



spreading thence inland in all directions. They are seen returning to their 

 continental breeding-grounds from early in February to mid- April ; (2) flocks, 

 not so large, coming from Scandinavia, arrive between mid-October and mid- 

 November in the Orkneys and Shetlands, thence spreading south as far as the 

 English northern counties. The return migration takes place in March and April, 

 the birds quitting our shores chiefly by way of the Orkneys and Shetlands ; 

 (3) between the end of February and early April flocks from the Continent arrive 

 on our south-east coast, flying in a north and north-west direction. In September 

 and October there is an emigration presumably of the same birds, flying in the 

 direction of France and Belgium ; (4) there is an emigration from Great Britain 

 to Ireland in the autumn, with a return to the former in the spring. Hence it will 

 be seen that the rook, besides being a resident species, is both a winter and summer 

 visitor. In addition to the above migrations, erratic westerly movements over 

 the Atlantic have been observed. In October 1893 some thousands, accom- 

 panied by a few daws, were seen going west over the Scilly Isles. Later, flocks, 

 probably the same, were seen arriving in a state of exhaustion on the west coasts 

 of Scotland and Ireland, and several were washed ashore dead. [F. B. K.] 



4. Nest and Eggs. Nesting place : normally in colonies among tree-tops, 

 exceptionally between the pots on chimney-stacks, on church spires, rarely in 

 bushes and hedges. Nest : sticks, dry and fresh, strengthened with earth and 

 lined with moss, leaves, roots, grass, wool, hair. (PI. I.) Both sexes share in its 

 construction. The eggs, usually 3-5, sometimes 6, and rarely 7 in number, are 

 greenish with olive-brown markings, but vary considerably in appearance, and 

 are occasionally found with a bluish ground, while red eggs have been several 

 times recorded from the Continent. (PI. A.) Average size of 100 eggs, 1'6 x 1O6 in. 

 [40'7 x 27 mm.]. Laying begins usually in late March or April. Both sexes 

 incubate. Period of incubation, 14-21 days. In an incubator, 17-18 days (W. 

 Evans, Ibis, 1891). The young remain in the nest 4-5 weeks (S. E. Brock, A. 

 Taylor). One brood, although attempts are occasionally made to breed in the 

 autumn, but generally without success. [F. c. E. j. F. B. K.] 



5. Food. Chiefly worms, insects, slugs, and in the autumn acorns, seeds of 

 cones, and similar fruit; occasionally grain. In cold weather or drought they 

 become practically omnivorous, their dietary being like that of the preceding 

 species, except that they appear to be, as a rule, less addicted to carrion. The 

 young are fed by both parents, chiefly on worms and insects. [F. B. K.] 



6. Song Period. See p. 39. 



