The Crow in Its Relation to Agriculture. 11 



larity often come from localities widely separated, while circum- 

 stances diametrically opposite have been reported from neighboring 

 farms. Food of this sort forms an extremely small part of the annual 

 diet of the crow, less than 1 per cent (0.57) of the adult's and 1.6 

 per cent of the nestling's. As in feeding on wild birds, the crow's 

 visits to the poultry yard are most frequent during the period when 

 it has young to feed ; as a consequence, successful protective measures 

 undertaken in May, June, and July will reduce to a minimum the 

 crow's depredations on poultry. 



MAMMALS. 



In feeding on mammals the crow supplements the good work of 

 hawks and owls by tending to hold in check rodent pests. Such 

 food forms 1.6 per cent of the diet of adult crows and 8.8 per cent 

 of nestlings. Their favorite mammal food consists of young cotton- 

 tail rabbits. While the crow does molest such live stock as young 

 lambs and swine, this is only an occasional habit when the bird is 

 hard pressed for food. Fortunately such work is not common and 

 the aggregate loss of this kind is negligible. 



CARRION AND THE DISTRIBUTION OF LIVE-STOCK DISEASES. 



As a carrion feeder the crow ably supplements the good work of 

 the turkey buzzard, especially along river banks and tidal flats, 

 where dead fish furnish a supply of animal matter much needed 

 during winter. But, from its carrion- feeding habits, the crow has 

 been accused of being a potent agency in the transmission of live- 

 stock diseases, especially hog cholera. No doubt the transmission of 

 this disease by the crow is within the range of possibilities, either 

 by the carrying of virus attached to its feet, bill, or other parts of 

 its body or possibly by the depositing of infected excreta after the 

 bird had fed on the body of an animal that had died from the dis- 

 ease. However, by the immediate burying of the dead bodies of dis- 

 eased animals and the employment of rigid sanitary measures in out- 

 breaks of this kind, the incentives which usually attract these birds 

 may be eliminated. It is well to add that many other agents in the 

 spread of such diseases, including dogs, cats, and innumerable in- 

 sects, are as potent in the dissemination of bacteria as are crows. 

 All of these can be made innocuous by thorough methods of sanita- 

 tion, while the extermination of the crow would eliminate only one 

 of many means by which such diseases are transferred. 



VEGETABLE FOOD. 



CORN. 



Vegetable matter forms nearly 72 per cent of the adult crow's 

 yearly food, and over half of it consists of corn. In November, De- 



