MAMMALIA 251 



mammals and a few are reptiles. Although they have already been 

 noted a few of them will be here recalled. Probably the most useful 

 of the natural enemies of field mice are the owls. Fig. 158 is striking 

 evidence of the feeding habits of owls. In 360 pellets of the long-eared 

 owl Dr. Fisher found 349 skulls of meadow mice. 



From its habit of living near dwellings the familiar little screech owl 

 is also useful as a destroyer of house mice, as well as field mice, not to 

 mention English Sparrows. With the possible exception of the great 

 horned owl, the owls should be rigorously protected. Most of the 

 hawks, herons, cranes, gulls, shrikes, crows, cuckoos, and other of the 

 larger birds are also useful as destroyers of field mice. 



Among the mammals that prey on field mice are the skunks, weasels, 

 opossums, raccoons, foxes, wildcats, coyotes, etc., also domestic cats 

 and dogs. Possibly the wild and domestic cats, especially the latter, 

 do more harm than good, but it is likely that in most localities the others 

 much more than pay for the few birds and chickens they destroy 

 by the numberless rodents they eat. This is especially true of the 

 skunks which are inveterate hunters of field mice, grubs and other pests, 

 and very seldom molest poultry yards. The value of their hides causes 

 them to be so persistently hunted that in many sections they have 

 been nearly exterminated. It might be well if the sale of their skins 

 should be prohibited. Black snakes, bull snakes, house snakes and 

 other of our larger snakes are excellent mousers, or even ratters and 

 should be protected. 



Most of the natural enemies of mice mentioned above are also very 

 useful as destroyers of rats. Those that are too small to attack a full 

 grown rat could easily handle a young one and it is thought by some that 

 a skunk or even a weasel will not attack poultry so long as there are 

 rats about the premises. 



Farmers are slowly learning to realize that black snakes are very use- 

 ful animals to have about their barns, some of them claiming almost 

 complete freedom from loss by rats because of the presence of several 

 large black snakes that they carefully guard against injury. The 

 author has talked to several farmers who made this claim. It is often 

 difficult to prevent ignorant hired men (especially negroes) from 

 killing every snake, skunk, weasel, hawk, etc., that they see. 



Ground Squirrels. These serious pests are found in most of the west- 

 ern States, where they cause an annual loss of many millions of dollars, 



