396 



PRACTICAL ZOOLOGY 



2 \ inches in diameter. Place the house in a position similar to 

 that of the wren. The top of a post is a favorable site. 



The bluebird's natural nesting place is a hollow in a stump, 

 fence post, or tree (Fig. 269). It often makes use of a tin can 

 lodged in a fence corner, and is partial to the old deserted nest 

 holes of woodpeckers. The nest consists of soft grasses. Five 



light blue eggs are 

 usually laid, and two 

 or three broods are 

 reared during the 

 nesting season. 



Bluebirds may be 

 looked for about the 

 last of March. They 

 mate about the last 

 week in April. Bird 

 houses for them should 

 therefore be in place 

 by the end of March. 

 Care must be taken 

 to protect the blue- 

 birds from the Eng- 

 lish sparrows, which 



FIG. 270. Screech owl. (Photo, by Hegner.) 



are ever ready to drive out the real owners and appropriate 

 the house. 



Unlike the other birds mentioned in this article, the martin 

 is sociable and seems to enjoy the company of its fellows. Its 

 house may be built with compartments which will allow several 

 pairs to occupy it at the same time. The compartments should 

 be about 9X7X7 inches inside. The entrances should be i\ 

 inches in diameter, near the top of the compartments. Many 

 elaborate and beautiful houses are possible, as the martins are 

 not afraid of homes constructed by human beings. The house 

 should be placed on top of a building or on a tall post. 



Suitable nesting places for the screech owl (Fig. 270) are not 



