394 PRACTICAL ZOOLOGY 



and plans must be made to keep the cats, sparrows, and jays 

 from disturbing the nests. If the house is in a tree or on a 

 post, a little barbed wire coiled around the post about five feet 

 below it will protect it from cats ; jays and sparrows cannot get 

 at the nest if there is no perch. 



FIG. 267. House wren carrying a stick into a nesting box. 

 (Photo, by Hegner.) 



The wren, although a very small bird, can use a relatively 

 large house (Fig. 267). It should be about 8X6X6 inches 

 inside. Near the top of one end an opening ij inches in diam- 

 eter should be made for the entrance. A perch is not necessary, 

 and is better left off, as it allows the English sparrows and other 

 depredators to get at the contents (Fig. 268). The house 

 should be placed in a tree or on the side of a building 7 to 15 feet 

 from the ground. It is safest when nailed to a building where 

 it is out of reach of cats. 



The little black-capped chickadee is almost exactly the size of 

 the wren, but uses a smaller house. A box 3X3X7 inches 



