Want to do something that’s good for bluebirds—and fun for you? Build them a nesting box! You’ll be charmed by the brilliant birds’ beauty and their cheerful singing. Since their diet consists primarily of insects and grubs, your garden may benefit, too.
In the past, bluebirds relied on woodpeckers and other cavity-dwellers to provide the majority of their nesting places. They’d select abandoned cavities in dead trees or rotten fence posts to raise their families. As development wiped out many of these natural nesting sites, the bluebird population declined dramatically. But man-made nesting boxes have played a vital role in reviving the beloved bluebird. They have fairly specific requirements, so these DIY birdhouse plans are designed to meet their needs.
Tips for Attracting Bluebirds to Nest
Bluebirds prefer to nest in open areas with low or sparse ground cover. The North American Bluebird Society, which provided the plans, says rural areas, cemeteries, golf courses and parkways with minimal human traffic are good places to mount these nesting boxes. Simply drive a 3/4-inch piece of electrical conduit into the ground and attach the house 5 feet above the ground with conduit straps as shown at right. Attach a predator guard and coat the pipe with grease to deter nest raiders.
This bluebird box has a couple of interesting features worth pointing out. It’s assembled with the rough side of the wood facing out so it more closely resembles the birds’ natural nesting sites. And there’s no perch. Notches beneath the entrance hole provide footing for bluebirds, but discourage visits from competing house sparrows and wrens.
The swing-open side is convenient, also. You can check for nests of unwanted birds (since house sparrows and European starlings are not protected by law, simply remove their nests) and have easy access for cleaning out the bluebird’s nesting materials after the young have fledged. You’ll want to do this immediately, since bluebirds often raise as many as three broods in one nesting season.
Best of all, the swing-open side will give you a chance to peek in on the nestlings for whom you’ve provided a sturdy and safe home. The side door is great for monitoring the activity in these birdhouses.
- One 4-foot 1-inch x 6-inch rough cedar board
- One 10-1/2-inch 1-inch x 10-inch rough cedar board
- 2-inch finishing nails
- 1-5/8-inch galvanized deck screws
- 8 feet of 3/4-inch conduit and two straps
- Table saw
- Power drill
Using the full width of a 4-foot 1-inch x 6-inch rough cedar board, cut the pieces as pictured in the board layout below. When making the angled cuts, keep in mind that all the pieces will be assembled rough side out.
Drill a 1-1/2-inch entrance hole in the front piece with a spade bit for eastern and western bluebirds. In areas where mountain bluebirds reside, drill the entrance hole 1-9/16 inches. Center the hole about 1-1/2 inches from the top of the board.
Starting about 1/2 inch below the entrance hole, make three shallow cuts about 1/4 inch apart on both sides of the front board. On a table saw, set the blade at 1/8 inch deep and use the saw's miter gauge to cut the notches. Flip the piece over and make identical cuts on the other side. If you want the front board to fit flush with the roof, cut an optional angle along the top edge by tilting the table saw blade 12°.
Position the sides flush with the top of the front board. Fasten the right side to the front with two 2-inch finishing nails. Fasten the left side to the front with a 1-5/8-inch deck screw near the top (drill a pilot hole first). Be careful not to over-tighten this screw because it will serve as a hinge for the side door.
Cut an optional 12° angle along the top edge of the back piece if you want it to meet flush with the roof. Then place the assembled front and sides on top of the back piece, leaving the top of the back board 1/4 inch higher than the sides. The space provides ventilation.
Turn the box over and attach the back to the left side of the box (the one with the "hinge") with a 1-5/8-inch deck screw. Drill a pilot hole first directly opposite the screw on the front (this ensures proper hinge action) and fasten with a screw. Again, don't make it too tight. Secure the other side to the back with three 2-inch finishing nails.
Cut about 1/2 inch off each corner of the floor to provide drainage. Position the floor 1/4 inch up from the bottom of the nest box. (Recessing the floor helps keep the box dry.) Attach the floor with 2-inch finishing nails on the front, back and right side. Do not use nails through the "hinged" left side or you won't be able to open it.
Drill a hole on the hinged side 2 inches up from the bottom and 1/2 inch in from the side. Drill at a slight downward angle, going through the front of the house and into the side. Make the hole large enough for a double-headed nail to slip in and out easily. Insert the nail to hold the side door closed.
Align the roof flush with the back and attach with 1-5/8-inch deck screws (drill pilot holes first).
The nest box is ready to mount. Keep the entrance hole about 5 feet above ground.
The Bluebird Society recommends attaching it to a smooth round pipe, such as a 3/4-inch electrical conduit, rather than on a tree or fence. Conduit straps attached to the back work well for mounting. For extra protection from predators, coat the pipe with grease and put hardware cloth under the box to deter snakes.
Face the box away from prevailing winds and towards a tree or shrub no more than 100 feet away. This will provide a landing spot for young birds when they first leave the box.