313 FUNDAMENTALS OF AGRICULTURE. 



solute failure of the grass crop has followed the de- 

 struction of birds by the farmers. Wherever the 

 numbers of field birds are greatly reduced, insects in- 

 crease and the grass crop suffers in proportion. 



Nesting Places. In the field, as in the forest, birds 

 find hidden nesting places, and an opportunity to rear 

 their young in safety; but the young suffer from the 

 effects of early grass-cutting, which exposes them to 

 the burning sun and to the attacks of their enemies, 

 even if they are not killed by the operations of hay- 

 making. Nevertheless the first broods of the early- 

 nesting birds usually are on the wing by haying time. 



Value of Garden Birds. In the garden, on the con- 

 trary, birds find little chance to breed, for the opera- 

 tions of tillage tend to destroy their nests. Now and 

 then a sparrow may safely rear her young in a potato 

 hill; but few birds can nest in the garden or cultivated 

 field, except where small fruits, trees, or vines are 

 planted. For this reason birds are less serviceable in 

 the garden than in field or forest. Birds which breed 

 in orchard or woodland are nevertheless of great utility 

 in gardens or cultivated fields nearby, and the birds of 

 the air, including the swallows, martins, swifts and 

 nighthawks perform some of their most beneficent 

 services unnoticed, while skimming over garden and 

 field. Doves, sparrows, blackbirds, larks, quail and 

 other ground-feeding birds destroy enormous quanti- 

 ties of weed seeds during all seasons when these seeds 

 are to be found. Prof. F. E. L. Beal estimates that 

 the tree sparrows of Iowa eat 875 tons of weed seeds 

 annually, and the experts of the Biological Survey have 

 computed that native sparrows save the farmers of the 

 United States $35,000,000 each year in this manner. 



Useful Species for the Farm. The thrushes are 

 valuable birds from the standpoint of the husband- 

 man. Chief among them is the American robin. 

 This bird, although noted for its fruit eating propen- 

 sities, is nevertheless one of the most useful species on 

 the farm. It feeds mainly on fields and cultivated land 



