276 USEFUL BIRDS. 



such insects. Without birds it is doubtful if crops of grass 

 could be raised ; for the grub of a single species of beetle, 

 if unchecked, could readily destroy all the grass roots of 

 our meadows ; and any one of several species of cutworms 

 or army worms might be sufficient to destroy all the crops 

 above ground. As it is, however, where the birds of the 

 field are undisturbed they tend to hold the grass insects in 

 check, so that the farmers are able to get good crops of 

 grass without using any insecticides whatever. Therefore, 

 we are largely indebted to birds for our grass crop. 



Wherever the numbers of birds are much reduced, there 

 is danger of a corresponding reduction in the grass yield. 

 Prof. J. Y. P. Jenks once told of an experience related to 

 him regarding an occurrence many years ago in Bridgewater, 

 Mass. A great hunt was held by the townspeople in the 

 spring of the year, and so many birds were killed that their 

 bodies were used to fertilize the soil. The following sum- 

 mer the trees in that town were stripped of their leaves, and 

 great patches of grass withered away and died. Such results 

 must be expected wherever the number of birds in a region 

 is suddenly and greatly reduced, and the pressure exerted by 

 them upon the hosts of insects is as suddenly released. 



In preparing the garden or cultivated field, natural condi- 

 tions are overturned. If in making a garden we desire to 

 use a piece of land covered with trees, we must first clear it. 

 By cutting trees and uprooting and burning stumps and 

 underbrush we remove the natural shelter and nesting places 

 for birds, and to a great extent destroy their food. Some 

 woodland insects may persist, and later attack the growing 

 crops ; but the birds which formerly lived in the woods are 

 driven away. 



If the land intended for our garden be natural meadow or 

 prairie, we must dispose of the grass, and so the sod is turned 

 under. As in the woodland, both the shelter and nesting 

 places of the birds are destroyed, together with most of 

 their food. Such insects as pass part of their lives in the 

 ground, like the white grubs and cutworms, may survive and 

 eventually come to live on the fruits of our labors ; but the 

 birds are driven out. 



