484 



THE NATIONAL GEOGRAPHIC MAGAZINE 



Photo from Stanley E. Piper, U. S. Biological Survey 

 MEN DISTRIBUTING POISON TO KILL THE MICE 



composed entirely of mouse fur and 

 bones. 



It is deplorable that, even when their 

 usefulness is as apparent as here, some 

 persons continue to destroy valuable 

 birds and mammals. During the investi- 

 gations in Humboldt Valley no less than 

 29 large hawks were found hanging on 

 wire fences, their useful lives ended by 

 thoughtless gunners. 



The striking evidence of the valuable 

 services of the natural enemies of mice 

 seen during this plague is but an example 

 of their constant value. Hawks, owls, 

 gulls, crows, ravens, herons, and shrikes 

 among birds, and skunks, coyotes, foxes, 

 weasels, badgers, and wildcats among 

 mammals, habitually prey upon field 

 mice, and are most valuable in prevent- 

 ing undue increase of these pests. 



Thorough studies have shown hawks 

 and owls to be most beneficial allies of 

 the farmer, orchardist, and nurseryman. 

 Most species rarely, and many of them 

 never, attack poultry. In the Nevada 

 valleys all species of hawks and owls 

 are distinctly beneficial, and here rig- 



orous protection cannot be too strongly 

 advocated. 



Among mammals the weasel and the 

 skunk are especially worthy of protec- 

 tion. They are most persistent enemies 

 of mice, and are less likely to be driven 

 out by civilization than are other mam- 

 mals. When particular individuals raid 

 poultry houses it may be necessary to 

 destroy them, though usually it is easy to 

 make such houses proof against their 

 attacks. Far from being a menace, they 

 are generally most beneficial mammals, 

 and, living, are worth many times the 

 value of their pelts. 



It is gratifying to note that in many 

 localities the people are learning to ap- 

 preciate these natural enemies of rodent 

 pests, for even more important than leg- 

 islation for the protection of valuable 

 birds and animals is the recognition of 

 their services by the farmers. 



In Nevada it was noticed that hawks 

 and owls hunted chiefly in fields near the 

 few plantations of large trees to be found 

 in the valleys. Beneath these trees the 

 ground was fairly carpeted by disgorged 



