218 PROPAGATION OF WILD BIRDS 



Gourds. These are very popular with wrens, and with 

 martins in the South. Bluebirds also use them, and prob- 

 ably others would do so. In the South I have seen gourds 

 tied in rows on crosspieces attached to poles, and occupied 

 by colonies of martins. A suitable hole should be cut in the 

 side of the gourd, and a small one underneath for drainage. 



Starch Box. This is taken as the type of similar ready- 

 made boxes which can be utilized. Tree swallows use them 

 readily if placed on poles. The crested flycatcher is as 

 likely to appropriate them as anything else. Bluebirds and 

 wrens also occupy them. Always cut the whole near the top. 



Earthenware. Some dealers have put on the market 

 boxes of earthenware or crockery. While birds may some- 

 times use them, they are evidently not popular. It would 

 seem as though the young might have trouble in climbing 

 out, and that the material would be apt to absorb heat. 



Bark Boxes. These can be made from strips of bark, in 

 the form of a hollow log, with the ends fastened up and a 

 hole cut. They will hardly last, though, more than one 

 season, and the stronger board material is doubtless better. 

 William Brewster, as noted above, has found these very 

 effective, as also sections of hollow limbs boarded up at the 

 ends, with a hole cut in the side. 



Martin Houses. Purple martins prefer to nest in col- 

 onies, and like best of all houses built with compartments, 

 although they will sometimes locate where there are a series 

 of boxes or gourds. The compartments may each be 6 to 8 

 inches square. The hole should be near the floor level, say 

 about an inch or two above it. Most birds prefer a hole 

 just large enough for them to enter comfortably, but the 

 martins seem afraid to enter an opening small enough to 

 have their bodies shut out the light as they enter. Two 

 and one half inches diameter is the aperture suggested in 



