INTRODUCTION. 13 



but these birds are valuable as food, and as a consequence have been 

 nearly exterminated in some States, and their numbers are fast being 

 depleted in all. They can no longer be depended upon as allies of the 

 farmer. The same is true of many animals, like the skunks and foxes, 

 and also snakes, all of which, for different reasons, are killed when- 

 ever possible. So it is that their natural enemies having been exter- 

 minated or much reduced in numbers, noxious insects, such as grass- 

 hoppers, have a chance, when favored by exceptionable seasons, to 

 multiply to an astonishing extent; and so it is that having multiplied 

 to a degree impossible to calculate, they suddenly assume the offen- 

 sive, and, like an invading army, take possession of the whole country 

 and strip it of every green thing. Surely no more economical method of 

 holding these hordes in check can be desired than the fostering of 

 means already provided by nature. Apparently quite ignorant of the 

 habits of hawks and owls, the legislature of at least one of the West- 

 ern States — Colorado — some years since passed a bounty act which in- 

 cluded these birds. As a result thousands of grasshopper- eating hawks 

 were destroyed at the expense of the State — an expense by no means 

 to be estimated by the number of dollars paid out as blood money; for 

 if the destruction be carried far enough and the birds of prey actually 

 exterminated, there is every reason to believe that sooner or later one 

 of the consequences will be another grasshopper plague.* 



The Broad- winged Hawk is another species which feeds to a consid- 

 erable extent on insects, destroying vast numbers of grasshoppers and 

 crickets. It is especially fond of the larvaB of the large moths which 

 feed on the leaves of fruit and shade trees, and during the late summer 

 and early autumn it is exceptional to find one that has not been indul- 

 ging in this kind of food. Snakes, toads, frogs, and the smaller rodents 

 also form a considerable portion of its fare. It rarely attacks birds. 



The little Sparrow Hawk is the only one of the true falcons which 

 can be placed in the present class, and, although at times it follows 

 the example of its larger congeners and attacks small birds and young 

 poultry, these irregularities are so infrequent compared with its con- 

 stant good service in destroying insects and mice that they are hardly 

 to be considered. It is, in fact, too small to cope with any but very 

 small chickens. Grasshoppers and crickets form its principal food 

 during the warmer months, while mice predominate during the rest of 

 the year. 



Among the owls of this class which deserve special mention the Earn 

 Owl is probably the most important from an economic point of view. 

 and it is questionable whether it should not have been placed in the 

 previous class, as its food is almost entirely made up of injurious mam- 

 mals. In the West it feeds very largely on pouched gophers, and the 



* The writer, who passed through the counties of Bent and Logan in July, 1892, 

 saw every indication of the commencement of another grasshopper plague, as myriads 

 of grasshoppers were feeding on the alfalfa and wheat. 



