390 Biology in America 



The abundance of the mice in Humboldt Valley attracted 

 hawks in large numbers to feast upon the good things which 

 Nature had so bountifully provided for them. But failing 

 to recognize in the hawks their best ally in their war against 

 the mice, the ignorant residents seized their guns and pro- 

 ceeded to slay their best friends; so that a traveler through 

 the valley observed twenty-nine of these Birds hanging on 

 the fences. 



So too thought the legislature of Pennsylvania when in 1895 

 they passed the notorious ' ' scalp act, ' ' providing for a bounty 

 of fifty cents for every hawk or owl killed within the state, 

 as a result of which half-baked legislation more than 100,000 

 valuable birds were killed, at an expense of nearly $100,000 

 to the state for bounties and notary fees, and an estimated 

 loss of more than $4,000,000 from the increase of harmful 

 rodents resulting from the destruction of their enemies, the 

 hawks and owls. And yet all this in the short space of a 

 year and a half. Fortunately the legislature soon recovered 

 its equilibrium and the law was repealed. 



But how do we know that the hawks and owls, or at 

 least most of them, are the farmer's friends rather than 

 his enemies? A few specific facts will best answer this 

 query. 



Hawks and owls have a habit of throwing up the undi- 

 gested parts of their food in the form of pellets containing 

 the hair, bones, feathers, etc., of their prey. For many years 

 a pair of barn owls were wont to nest in the tower of the 

 Smithsonian Institution in Washington. An examination of 

 two hundred pellets found beneath their nesting site revealed 

 454 skulls, of which 412 were those of mice, 20 of rats, 20 

 of shrews, one of a mole, while only one was that of a bird 

 (sparrow). 



In the " Pacific Rural Press" for Oct. 23, 1897, is an account 

 of a pair of these same birds nesting in a pigeon house, whose 

 owner, supposing that they were feasting on his pigeons, shot 

 the male and trapped the female. Upon examining the nest 

 he found ten young ''gophers" (ground squirrels?) in it, 

 whereupon he promptly released the female. 



Of 146 stomachs of the great-horned owl examined, only 

 31 contained poultry and 8 other birds, the remainder con- 

 taining various mammals, insects and miscellany. 



An examination of 562 stomachs of the red-tailed hawk 

 showed remains of poultry or game birds in 54, other birds 

 in 51, mice in 278, other mammals in 131, insects in 47, mis- 

 cellany in 59, and nothing in 89. 



It was primarily to answer questions such as these that 

 the U. S. Biological Survey was organized in 1885, becoming 



