The Tree Swallow is often a bird of the small city, but may be expected more dependably in the country or in the rural community. He is easily satisfied as to a nesting place but it is sometimes difficult or impossible for him to find a nook about our dwellings which is safe from the English Sparrow’s intrusion. When nesting about inhabited buildings he cannot well afford to dispense with the vigilance of his human landlords. Small, quiet, and peace-loving, he is a particularly poor match for the pugnacious sparrow. Specifications for the Tree Swallow house are given in Table I. See also Plate III. The inner wall, between floor and entrance, must be rough or provided with cleats, in order to give the young a sure foothold. Several pairs of Tree Swallows will willingly nest near one another.
For the beautiful Violet-green Swallow build exactly as for the Tree Swallow. Where, in the west, both species occur, there is the chance that a house intended for the Violet-green will be taken by the Tree Swallow. This chance, otherwise more than an even one, may be lessened by catering to the Violet-green’s observed choice of local haunts. Barn Swallows will sometimes use ledges, such as those described for the Robin (page 29), when these are sheltered.
Beautiful, cheerful, demure, raising two or more broods in the season, always a picture of “content in a cottage,” the Bluebird is the all-round ideal tenant for the simple bird house. He is, however, not a bird of the city, nor always a bird of the village garden. The suburbs, especially the more secluded spots therein, suit him much better. He tends, and that with ample reason, to shrink from the society of English Sparrows whose rough, aggressive manners and harsh notes introduce discord into his naturally calm and peaceful existence. By all means provide a house for this peerless tenant; also be prepared to lend him all possible assistance in policing his property until the eggs are laid. Once the precious eggs are deposited, trust the prospective parents to defend their treasure; for even the Bluebird is no exception to the general rule that a brooding bird will readily put an erstwhile successful bully to speedy and inglorious flight. See Plate III and Table I for housing the Bluebird.