BUILDING BIRD HOUSES 



667 



Fig. 34. — Cross vertical section of martin 

 house; raised and doors open. 



Fig. 35. — Longitudinal vertical section of 

 martin house; lowered, and doors closed. 



the shelf must be provided with a roof. Figure 8 

 shows a shelf shielded from the weather by one 

 wall and a roof. This shelf if ]3laced high under 

 the eaves of a two-story building may attract 

 barn swallows; phoebes and robins also are 

 likely to build upon it if it is not less than 8 feet 

 from the ground. In some cases it will be 

 advisable to leave only one side open. 



A nest shelter designed to be placed in shrub- 

 bery for catbirds, brown thrashers and song 

 sparrows is shown in Figure 10. As it requires 

 little lumber or labor, one may well be placed in 



