JACKDAW. 29 



this season some, thought to be British-bred birds, leave our 

 south coast ; return north and eastward migrations occur in 

 spring. 



The Jackdaw, a much smaller bird than the Rook, with which 

 it freely consorts, has a proportionately shorter and straighter 

 beak, and by some authorities is placed in a separate genus, 

 Colceics. On the ground its movements are quick, almost 

 fussy ; it walks with a strut, jerking its body ; its wing-beats in 

 flight are rapid, readily distinguishable from those of the Rook. 

 Its flight is less direct, more erratic, and it frequently indulges 

 in aerial display, especially at its breeding-place ; here the birds 

 of a colony will engage in combined evolutions without con- 

 certed action ; each individual dodges, swerves, turns, twists or 

 dives at pleasure. These sociable performances, most notice- 

 able in the evening, are accompanied by incessant clamour, the 

 sharp and shrill cries of "tchack" or "cae" blending in 

 dehghtful harmony. The alarm note is similar to that of the 

 Rook, though not so deep in tone. The food is mainly insects, 

 worms and molluscs, but eggs and young birds are freely 

 devoured in spring, and a little fruit and corn is taken. To 

 obtain a favourite insect, the "ked '' or spurious sheep-tick, the 

 Daw perches on the sheep's back and searches the wool ; it 

 will also pick hair from the backs of horses and cattle as lining 

 for its nest. 



The gregarious instinct is strongly developed in the nesting 

 habits, though less so than in the Rook ; solitary nests are 

 exceptional. The colonies are in crag or cliff faces, woods or 

 ruins, and the nest is usually placed in a hole or crack in rock, 

 tree or masonry. Open nests are, however, built in trees, 

 occasionally in rookeries ; the habit of nesting, feeding and 

 flying with Rooks appears to be growing, and may be due to 

 the general increase of the bird. When placed in a hole the 

 nest may be little more than a lining, but when in branches 

 or buildings great quantities of sticks are used ; indeed, 



