412 INFLUENCES OF CULTIVATION 



the stocks of oats in the harvest fields for their grain. Again, 

 Mr O. H. Wild tells me that he has seen Mallard flying 

 deliberately and regularly inland to potato fields where they 

 consumed sufficient to damage the crop appreciably,' and 

 Rev. J. M. McWilliam relates a similar story of the Wigeon. 

 Gulls, too, especially the Black-headed and the Common Gull, 

 have left the seashore and the marsh to follow the plough, 

 and may be. seen on summer evenings chasing moths in 

 pasture land. It is generally supposed that in the fields they 

 confine their attention to grubs and worms, but while these 

 no doubt form the larger share of their new diet, examination 

 of their gizzards convicts them of an unsuspected taste for 

 grain and even turnips. In North Ronaldshay, in the Orkney 

 Islands, turnips have formed a staple part of the autumn 

 food of Gulls for close on forty years, and during the last 

 dozen years, the turnip-eating habit has become common in 

 parts of Aberdeenshire. 



A notable change in the feeding habits of the Grey Lag 

 Goose is clearly traceable to the influence of cultivation. 

 In North Uist, Mr F. S. Beveridge has recorded, towards 

 the end of August when oats have begun to ripen, the 

 Geese appear in considerable flocks, select the most con- 

 venient field and proceed utterly to demolish it. If the grain 

 be too high to be reached comfortably, the Geese beat the 

 crop flat by settling on it in closely packed flocks, or by 

 beating it with their wings. After the grain has been har- 

 vested, they turn their attention to the potato crop, if the 

 weather be severe and more natural food unobtainable. 



One little change of habit, a local migration, may be 

 noted in closing this account of the influence of civilization 

 and cultivation on habits of feeding. Every spring there are 

 reared in the safety of the large towns millions of Sparrows, 

 which, so soon as the grain harvest in the neighbouring- 

 country approaches, forsake the habitations of men and seek 

 the fields in countless hordes. On dry summer days, clouds 

 of town Sparrows, recognizable by their dusky plumage, may 

 be raised from any cornfield within miles of a great city, and 

 there they spend the summer and autumn taking heavy toll 

 of the ripening ears, and returning to the warmth and abun- 

 dant food of the city in winter. These migrations between 

 city and surrounding country are now carried out regularly 



