Diagram A. Draw
the outline of all pieces on the lumber with a pencil and a ruler. Check to make
certain that each piece is the correct size.
the pieces along the pencil outline. Cut the top corner off both side pieces to give
the nest box good ventilation. You should cut a triangle with sides measuring about
small (1/4" - 3/8") holes in the floor piece. These holes will let rain drain
out of the box and should be located as shown in the diagram.
holes (1/8" diameter) in the back piece, two at the top and two at the bottom. Each
hole should be 1" in from the corners. These holes will be used to mount the
Use a hole saw
to drill a 1 1/2" diameter hole in the center of the front board, 1 1/4" from
the top (as shown in the diagram). Drill another 1 1/2" hole in the predator
guard with your hole saw, down 1/2" from the top. Nail the predator guard to
the front of the box, aligning the entrance holes. The thick predator guard will
make it difficult for raccoons and other predators to reach into the box and grab eggs or
young at the bottom of the box.
You are now
ready to assemble your box. Before hammering or screwing pieces together, drill
small pilot holes where nails or screws will go. The diameter of the pilot holes
should be slightly smaller than the diameter of the nails or screws you use.
Pre-drilled holes help prevent the wood from splitting and make it easier to hammer pieces
side board to the front piece with a screw, placed 1" from the top of the front piece
and 1 1/2" from the top of the side boards. (The bottom edge of the side and
front boards should be aligned. The top of the front piece will be 1/2" lower
than the top of the side pieces, allowing the front to pivot to open the box.) The
screws go through the side boards and into the front piece (see diagram for placement).
Since these two screws let the front of the box pivot open, they must be
exactly the same distance from the top.
floor board next. Position it so the grain of the wood runs from side to side. Nail
the floor board in place.
Nail the back
in place. Center the box along the back board. This allows room at the top and
bottom of the back to mount the box.
Nail the roof
firmly to the top of the box. There should be a 1/2" gap between the front of
the box and the roof, allowing the front to pivot open.
Drill a pilot
hole through the bottom center of the front board into the floor board and insert the
L-shape or flat-head screw. To open the box, remove this screw. An L-shape
screw is easiest to unscrew, but if your box will be placed in an area where a person
might tamper with it, insert a flat-head screw.
mount your box, install a piece of 3/8" hardware cloth, 1" above the floor of
the box. You will need a piece of screen that measures 4"x6". Fold
the edge over 1" on two sides. The screen now measures 4"x4" and fits
in the bottom of the box. This screen will trap blowfly larvae below the bluebirds' nest,
so the insects cannot harm the baby birds. When blowfly larvae find bluebirds, they
such the bird's blood and can kill young bluebirds.