Part IL] NATURAL ENEMIES OF BIRDS. 225 



Brown Rat {Rattus norvegicus). 

 The status of the rat is peculiar. It may be domesticated 

 but ordinarily it is neither a wild nor domesticated animal but 

 is domiciled as a parasite on mankind. Rats when numerous 

 destroy eggs and attack the young of many species of birds. 

 I have treated this subject in Bulletin No. 1 of this series. 



FERAL ENEMIES. 



Mammals. 



The larger native carnivorous, mammalian enemies of birds, 

 the bear, puma and wolf, have been extirpated from IMassa- 

 chusetts and need not be considered. The two species of lynx, 

 or so-called wildcats {Lynx ruff us ruff us and Lynx canadensis 

 canadensis), are now rare and local, and where they are found 

 they feed more on mammals, such as hares, than on birds. Of 

 all the larger native enemies of birds, next to the wild house 

 cat the fox is the most important because of its ability to 

 maintain itself in considerable numbers in a thickly settled 

 country. 



Red Fox (Vulpes fulva fulva). 



In the natural order of things the fox, no doubt, is beneficial 

 as a regulator of the numbers of mice, insects and other small 

 animals, but we have destroyed its natural enemies, and it 

 is so crafty that it is able to exist, thrive and multiply unduly 

 in settled communities where, unless held severely in check, it 

 may become destructive to poultry, game and birds, and so 

 detrimental to the public welfare. 



If I were to consult only my own experience in tracking foxes 

 for many miles and studying their food habits I should regard 

 them as almost wholly beneficial, and as living mainly on mice, 

 insects, refuse scraps and wild fruit, varying their fare with an 

 occasional cat or a woodchuck, but many correspondents have 

 sent me notes which go to show that foxes when numerous 

 may become nuisances or even pests. I have published else- 

 where a little of this evidence.^ 



' Special Report on the Decrease of Birds and its Causes, fifty-second annual report, Mass. 

 State Board of Agr., 1904, pp. 490-498. 



