NATURAL ENEMIES OF THE RAT. 



By DAVID E. LANTZ, 



Assistant Biologist, United States Department of Agriculture. 



INTRODUCTION. 



Undoubtedly the great increase of rodent pests throughout North 

 America is in large part due to a general scarcity of the animals that 

 habitually prey upon them. Since the early settlement of the coun- 

 try persistent warfare has been made on birds and mammals of pre}^ 

 on the plea that they are enemies of poultry, game, and insectivorous 

 birds. Efforts to destroy the predaceous birds and mammals have 

 been greatly stimulated by the payment of municipal, county, and 

 state bounties, and the destruction has gone on until in many sections 

 these animals have nearly disappeared. 



The effect of killing off the natural enemies of rodents has been to 

 disturb natural conditions. Rodents multiply so rapidly that they 

 derive an undue advantage in the struggle for existence when their 

 natural enemies are destroyed. The result is noticeable in the 

 increased depredations of rats, field mice, rabbits, and other pests. 



The destruction of carnivorous wild mammals and birds by the 

 farmer, hunter, or game preserver is often due to misapprehension. 

 Because one kind of hawk preys on the farmer's poultry is not suffi- 

 cient reason for exterminating all hawks. Nor does the fact that 

 occasionally an owl or a skunk destroys a chicken or a game bird 

 justify warfare on all owls and skunks. It is the occasional individual 

 and not the species that offends. 



ANIMALS THAT DESTROY RATS. 



The usefulness of the natural enemies of the rat must not be over- 

 looked in plans for its repression. Among the more important are 

 the larger hawks and owls, skunks, foxes, coyotes, weasels, minks, 

 and a few other wild mammals; as well as cats, dogs, and ferrets 

 among domestic animals, and snakes and alligators among reptiles. 



HAWKS. 



Most of the larger hawks destroy rats. Feeding only in the day- 

 time, they seldom find their quarry near houses and barns, where rats 

 do not venture out until after sunset. Besides, owing to persecution 



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