BIEDS 89 



do much harm by the distribution of seeds of poison ivy, 

 poison sumach, and perhaps other noxious plants. (6) They 

 do much harm by the destruction of beneficial insects. On 

 the other hand : (1) They do much good by the destruction 

 of injurious insects. (2) They are largely beneficial through 

 their destruction of mice and other rodents. (3) They are 

 valuable occasionally as scavengers." W. B. BARROWS, 

 " The Food of Crows." 



FIG. 74. The crow. 



While most of the hawks are undoubtedly beneficial (69), 

 two species, namely, Cooper's hawk and the sharp-shinned 

 hawk, must be kept down to limited numbers. Both of 

 these are " chicken-hawks," and in addition they ruthlessly 

 destroy great numbers of our most valuable wild birds. 



72. Summary of the relation of birds to human welfare. 



Library study. 



For further facts like the following, consult, Weed and Dear- 



