392 BRITISH BIRDS. 



worm destroy in its three or even five years of life? Some 

 hundreds of thousands, and thus by killing the pest the rook 

 must be saving all those future doomed plants that come in the 

 wireworm's way. They can easily be kept off the standing 

 corn, which they sometimes damage, breaking down the stalks 

 and causing havoc in it gdnerally. We must remember that 

 any animal or bird in excess is sure to be injurious, and thus 

 where we can see any undue increase we may justifiably kill 

 some off. In the rook this is essential, for where they become 

 too abundant they undoubtedly do much mischief, if there are 

 not enough grubs for them to feed upon ; but in moderate 

 numbers they cannot be otherwise than useful. 



The Jackdaw (C. monedula), which is much smaller than the 

 rook and told by the grey colour of the back of the head and 

 nape of the neck, is often found in company with it. They 

 accompany rooks to their feeding-grounds, and nest if they can 

 somewhere near rookeries and the haunts of men. The most 

 favourite nesting - places are hollow trees, cliffs, and church- 

 towers. Jackdaws feed upon insects, grubs, fruit, and all 

 manner of strange objects, which they delight to obtain and 

 destroy. On the whole, they too may be considered useful birds 

 to the farmer. 



The Magpie {Pica caudatd) and the Jay (Garrulus glandarivs) 

 are both harmful, eating not only insects but the eggs of many 

 of our insect-feeding birds, ducklings, chicks, and game, grain, 

 cherries, as well as wild fruits. A few voles may make up the 

 bill of fare. The magpie is found in open country; the jay, 

 with its harsh screaming note, in woodland tracts, where it 

 falls a ready victim to the gamekeeper's gun. 



Starlings (SiURNiDiE). 



The genus Sturnus has a bill as long as the head, the edges 

 of the upper mandible extending over those of the lower 

 mandible. 



