BIRDS IN RELATION TO AGRICULTURE 181 



construction and size is a matter upon which taste can be 

 exercised if the following directions are followed: 



If possible they should contain not less than ten to twelve 

 rooms. The individual chambers should measure six inches 

 square and high, and they should be completely separated 

 from the adjoining chambers. The entrance holes should 

 measure two and one-half inches in diameter, and the 

 centre of the hole should be slightly above the centre of the 

 outer side of the chamber. 



2. The Destruction of Enemies 



The greatest enemy to bird life in more thickly populated 

 districts is the domestic cat. After many years' experience 

 I have arrived at the conclusion which all lovers of bird life 

 reach, namely, that no matter how carefully a cat is cared 

 for by its owners, its bird hunting and destroying instinct 

 is not greatly diminished. Naturally, stray cats will destroy 

 a large number of birds, and such garden-loving species as 

 robins and yellow warblers fall an easy prey. The destruc- 

 tive character of the cat has been well described by E. H. 

 Forbush in his book, "Useful Birds and Their Protection," 

 and in other pubUcations. The following evidence is given 

 in his book: 



Mr. William Brewster tells of an acquaintance in Maine who said that 

 his cat killed about fifty birds a year. Mr. A. C. Dike wrote of a cat 

 owned by a family and well cared for. They watched it through one 

 season and found that it killed fifty-eight birds, including the young in 

 five nests. 



Nearly a hundred correspondents scattered through all the counties of 

 the state (Massachusetts) report that the cat is one of the greatest enemies 

 of birds. The reports that have come in of the torturing and killing of 

 birds by cats are absolutely sickening. The number of birds killed by 

 them in this state is appalling. 



Some cat lovers believe that each cat kills on the average not more 

 than ten birds a year; but I have learned of two instances where more 

 than that number were killed in a single day, and another where seven 



