234 BIRD FRIENDS 



has the entrance hole near the top, and has the 

 roof project well out over the hole. 



Size of entrance hole. Two features of the en- 

 trance hole are of great importance, its size and lo- 

 cation. The size is important because this enables 

 one to keep out larger birds than the one for which 

 the house is intended. This is one successful way 

 of keeping out the English sparrow from houses 

 intended for the wren and the chickadee, and the 

 starling from houses intended for these birds and 

 for the bluebird and the tree swallow. 



The smallest hole the English sparrow can enter 

 is one and a quarter inches, and the starling one and 

 three quarters inches. Thus a one-and-one-eighth- 

 inch hole will exclude the sparrow and a one-and- 

 five-eighths-inch hole the starling. 



The birds may be classed in four groups accord- 

 ing to the size of the hole needed : — 



First group: small birds that can use a hole too 

 small for the English sparrow, one and one eighth 

 inches or less; chickadee, house wren, Bewick's wren, 

 Carolina wren. 



Second group: medium-sized birds that can use 

 a hole too small for the starling, one and one fourth 

 inches to one and five eighths inches; tufted tit- 

 mouse, white-breasted nuthatch, downy wood- 

 pecker, bluebird, violet-green swallow, tree swallow, 

 hairy woodpecker. 



Third group : large birds that require an entrance 



