I Q4 ECONOMIC ZOOLOGY 



"By virure of this act about $90,000 has been paid in bounties during 

 the year and a half that has elapsed since the law went into effect. This 

 represents the destruction of at least 128,571 of the above-mentioned animals, 

 most of which were hawks and owls. 



"Granting that 5000 chickens are killed annually in Pennsylvania by 

 hawks and owls, and that they are worth 25 cents each (a liberal 

 estimate in view of the fact that a large proportion of them are killed when 

 very young), the total loss would be $1250, and the poultry killed in a year 

 and a half would be worth $1875. Hence it appears that during the past 

 eighteen months the State of Pennsylvania has expended $90,000 to save 

 farmers a loss of $1875. But this estimate by no means represents the 

 actual loss to the farmer and the tax-payer of the State. It is within the 

 bounds to say that in the course of a year every hawk and owl destroys at 

 least a thousand mice or their equivalent in insects, and that each mouse or 

 its equivalent so destroyed would cause the farmer a loss of two cents per 

 annum. Therefore, omitting all reference to the enormous increase in the 

 numbers of these noxious animals when Nature's means of holding them in 

 check has been removed, the lowest possible estimate of the value to the 

 farmer of each hawk and owl would be $20 a year, or $30 in a year and a 

 half. 



"Hence in addition to the $90,000 actually expended by the State in 

 destroying 128,571 of its benefactors, it has incurred a loss to its agricultural 

 interests of at least $3,857,130, or a total loss of $3,947,130 in a year and 

 a half, which is at the rate of $2,631,420 per annum. In other words the State 

 has thrown away $2,105 for every dollar saved. And even this does not rep- 

 resent fairly the full loss, for the slaughter of such a vast number of predaceous 

 birds and mammals is almost certain to be followed by a corresponding 

 increase in the number of mice and. insects formerly held in check by them, 

 and it will take many years to restore the balance thus blindly destroyed 

 through ignorance of the economic relations of our common birds and 

 mammals." Fortunately this law was soon repealed. 



As noted above there are a few birds which do more harm than good 

 and a few whose economic value has not been definitely determined. 

 As an example of the former group the English Sparrow stands out. 

 Introduced into this country first at Brooklyn, N. Y., in 1850, and later 

 into various States, the House Sparrow, popularly named from the 

 country whence it was brought, has spread over practically the entire 

 country and parts of Canada. It is supposed to have been introduced 

 for two main reasons: to destroy certain insects then damaging crops 

 and for sentimental reasons by persons of foreign birth who wanted to 



