Bluebirds require houses a little larger than the wrens, with larger doorways. The floor space should be at least 5 inches square, the doorway 1 1/2 inches in diameter. The height to place the house above the ground is from 5 to 10 feet. Comply with these requirements, see that the house is not disturbed by cats and other unwelcome intruders, and it is almost certain that Mr. and Mrs. Bluebird will be perfectly contented with their new quarters, and, with good fortune, will raise their customary two broods.
Bluebird houses can either be hung from a tree limb or be supported upon a pole. Figure 686 (Chapter 38) shows a hanging bluebird house and Fig. 696 shows the same house mounted upon an iron-pipe support.
If you hang the house, fasten it close up to a tree limb so that it will not swing much, for a swinging house does not strike the fancy of the average pair of bluebirds. The house mounted upon a pole seems to be preferred.
The two-compartment bluebird house shown in the illustrations makes an attractive little structure for the garden or lawn, and it is simple to build.
In the cross-section of Fig. 697, which is a cross-section of The Hanging-House, each piece is lettered, and in Fig. 698 you will find patterns of all the parts, similarly lettered. Walls A and center partition E should be cut out of material 7/8 inch thick, the other pieces may be cut out of box boards 3/8 inch thick.
Prepare walls A first. If you will draw a center-line, then upon one side of this line draw one-half of the piece, you can take a piece of thin paper, make a tracing of the half, and transfer it to the other side of the center-line to complete the piece.
By doing this you will find it easy to get both sides alike. Fasten together two pieces of board with several nails driven part way in, draw the outline of the wall upon one board, and ‘saw out the two pieces at one time. Both pieces will then be alike.
Before separating the cut-out pieces, plane up their edges. With walls A prepared, cut out center partition B, walls C, roof moulding D, roof boards E, ridge-piece F, and floor G.
If you haven’t an expansive-bit that can be adjusted to cut holes 1 1/2 inches in diameter, for the doorways, bore several small holes in walls C, and cut out the wood between them to make 1 1/2-inch opening.
The tops of walls C must be beveled to correspond with the pitch of the roof, as must also the tops of moulding strips D. Ridge-piece F must be grooved to fit over the roof ridge, as indicated in Figs. 697 and 698.
In Assembling the House, first fasten partition B between walls A, then nail moulding strips D to walls C, and fasten walls C between walls A, close up against strips
D. Care must be taken to get walls A exactly opposite, else the entire structure will be lopsided. Next, fasten roof boards E in place, being careful to get the end projections equal. With the roof nailed on, fasten ridge-piece F to it.
The Floor is Made Removable so that the compartments will be accessible for the annual house-cleaning. The floor board (G, Fig. 697) slides in between walls A, above perch-sticks H, and is held in position by nine wooden wedges (K Fig. 697) wedged in between it and the perch-sticks. Bore 1/4-inch holes through walls A, about 3/4 inch below the floor, to receive The Perch-Sticks H. Dowel-sticks may be used.
The bottom perch-stick H runs through a pair of blocks I cut to the dimensions shown in Fig. 698 and hangers J (Fig. 698) run into holes bored through the corners of blocks I, and into holes bored in the center of the bottom edge of walls A (Fig. 697). Fasten the pieces with brads.
The Bluebird House on a Pole, shown in Fig. 696, is built in the same way as the hanging-house, up to the point of attaching the perch-sticks. The center perch-stick H (Fig. 697) is omitted, also the perch-stick suspended beneath it. These must be left off to make room for The Iron-Pipe Support (Fig. 699). Get a piece of 1-inch or 1 1/4-inch iron pipe 10 or 12 feet in length, and have a plumber thread one end of it (M, Fig. 700).
Also get a threaded floor-flange (N, Fig. 700) to fit the pipe. Cut a piece of 7/8-inch board to fit against the under side of the floor of the house (L, Fig. 699), and fasten it to the floor, then screw the floor-flange to the board, in the right place to make it come exactly under the center of the house; and screw the end of the pipe into the flange (Fig. 701).
In a clay soil the pipe support will stand erect if driven several feet into it, but in a sandy soil it will be necessary to run some wire stays from the top of the pipe down to stakes driven into the ground several feet away from the base of the pipe.
A Permanent Way of Erecting the Pipe, is to set it in a hole and then to fill the hole with concrete.