Part II.] NATURAL ENEMIES OF BIRDS. 223 



Introduced Domesticated Enemies. 



Cat {Felis libyca domestica). 

 The cat, because of its numbers and intelligence, has no rival 

 in this country as a bird destroyer, except perhaps the dog in 

 States where there is no dog tax. Undoubtedly there are other 

 mammals and some birds which kill more birds individually 

 than the average cat; but the species, including strays, vaga- 

 bonds and those that have run wild and bred in the woods, 

 has become far more abundant now than any other animal 

 of equal individual destructiveness. I have already devoted a 

 bulletin to this subject (Economic Biology, Bulletin No. 2, 

 Massachusetts State Board of Agriculture, 1916), and cannot 

 spare more space to it here. 



Dog {Canis familiar is). 



The dog is believed to be individually even more deleterious 

 than the cat to certain birds which breed on the ground, but 

 it is not so skillful and crafty as the cat and cannot climb. In 

 Massachusetts dogs are not one-tenth as numerous as cats, 

 and most of them are kept under better control, while many 

 are confined to buildings or kept under the eyes of the owners. 



Dogs are readily taught to obey their masters, while cats 

 are not, and the dog license law has reduced tremendously 

 the number of dogs kept as well as the number of vagrant 

 dogs. In South Carolina, where there is no dog license law, 

 Miss Belle Williams, secretary of the State Audubon Society, 

 who has conducted a painstaking investigation of the decrease 

 of birds, finds that dogs are terribly destructive to birds in 

 nearly all parts of the State, Indigent negro families keep 

 many dogs, which are obliged largely to pick up their own 

 living, and therefore range the fields and woods, eating quan- 

 tities of eggs and young birds. The conditions in regard to 

 the dog there are similar to those that obtain in relation to the 

 cat in Massachusetts. Even here dogs are so numerous that 

 they have practically ruined the sheep industry, and driven 

 sheep from New Enjgland pastures where once many thousands 

 grazed. Many dogs here are allowed to roam and hunt at will. 

 Some owners never feed their dogs meat but permit them to 



