NESTING-HOUSES 43 



seems probable that as it increases it will help 

 drive away some of our more valuable native 

 birds and become eventually a pest like the Eng- 

 lish sparrow. On the whole, probably it is not 

 worth while to make any attempts to attract this 

 bird to our nesting-houses, for the present, at 

 least, till more is known about its habits and 

 value. 



Tree Swallows. — The tree swallow is a not 

 uncommon house-tenant in some sections of the 

 East. The boxes should be about twelve by six by 

 six inches, fastened with the longer axis vertical. 

 The entrance hole should be one and one half 

 inches in diameter. The boxes may be fastened 

 to trees, poles, or buildings. Place from eight to 

 twenty feet high. They should be put out just 

 as soon as the birds return in the spring. In 

 some instances these birds have been reported 

 as nesting in martin-houses which had not been 

 occupied by the martins. 



Violet-green Swallow. — This is one of the 

 commonest house-tenants in Oregon. Supt. L. R. 

 Alderman of Eugene, Oregon, writes : " We have 

 found that the violet-green swallow is eager to 

 inhabit any house that is out of the reach of cats, 

 and is firmly attached to any building, if it is 



