STRIPED SPBRMOPHILE 33 



These spermophiles do not go their way unmolested, for a num- 

 ber of natural enemies harass and kill them, thus holding the 

 numbers somewhat in check. Among the natural enemies of 

 spermophiles in the state may be mentioned the marsh hawk, 

 Cooper's hawk, red-tailed hawk and its subspecies, Swainson's 

 hawk and red-shouldered hawk ; of the owls, the barn owl and 

 the great horned owl render valuable assistance in keeping down 

 the numbers of this destructive rodent. Among the mammals 

 which also render efficient service along this line may be men- 

 tioned foxes, skunks, and the badgers, which, however, are com- 

 paratively rare in the state. In Dubuque county it is reported 

 that skunks do much towards keeping in cheek the numbers of 

 striped spermophiles and no doubt this holds true for other local- 

 ities in the state. Of the weasels the long-tailed species {Puiorius 

 longicauda) is of value in controlling the increase among sper- 

 mophiles for it enters the burrows and kills the occupants without 

 any difficulty. Some of the larger snakes such as the hog- 

 nosed snake and bull snake also destroy great numbers of spermo- 

 philes, particularly the young. 



So, even without the aid of man, Nature makes certain provisions 

 for keeping the numbers of these animals within reasonable limits 

 and for preventing a too rapid increase. Thus is obtained a "bal- 

 ance" in nature which Hudson Maxim has expressed as follows: 

 "The harmony of nature depends upon inharmony between the 

 meat-eaters (Carnivora) and the vegetable-eaters (Herbivora). 

 Their interests are, from their very nature antagonistic." 



In spite of the efforts on the part of Nature to keep matters 

 adjusted, man has interfered and disarranged the plan by de- 

 stroying many of his friends which are the enemies of spermo- 

 philes. As a direct result of this the number of these animals 

 has increased very markedly in many localities with a resulting 

 increase in the amount of damage. On this account the expedient 

 of offering a bounty has been tried in some counties, in few of 

 which it has been continued for any length of time. The bounty 

 situation is taken up more fully under the discussion on the pocket 

 gopher farther on in this bulletin and so will be but briefly con- 

 sidered here. A bounty, at best, can be but a temporary method 

 of reducing the numbers of these or any animals and is altogether 

 impracticable as a method of exterminating them. 

 3 



