244 BIRD FRIENDS 



entrance hole may be either square or circular, and 

 should be about two and a half inches across. The 

 best height for erecting the house is from fifteen to 

 twenty feet, although houses placed much higher 

 have been used. To prevent the English sparrow 

 from getting established early in the spring, the 

 house may be taken down in the fall and put up 

 again in the spring. This may be easily done if the 

 pole is put up as suggested on page 239. Directions 

 for making a simple house out of a barrel are given 

 in Mr. E. H. Forbush's "Useful Birds and Their 

 Protection." This type of house has been adopted 

 by the Meriden Bird Club. 



Most birds will use a hole which just permits 

 them to enter, but the martin prefers a hole large 

 enough to admit light while it is entering, so that 

 while it could just enter a one-and-five-eighths-inch 

 hole, the openings in martin-houses are made 

 about two and one half inches in diameter. As it 

 seems probable that starlings may drive martins 

 from their houses, it has been suggested that the 

 hole be made small enough (one and five eighths 

 inches) to exclude the starling and that a small hole 

 about one half inch in diameter be bored above the 

 entrance to admit light while the bird is entering. 



Providing nesting-material. There are still other 

 birds, which, while they will not allow us to choose 

 the exact site of their nest for tliem, may sometimes 

 be induced to nest in our immediate vicinity if som.e 



