The recent Summers Woodworking Birdhouse Challenge encouraged me to get into the shop and resurrect my birdhouse plans. Although I didn’t create a fancy birdhouse and I didn’t finish it in time to enter the contest, I enjoy making bird houses.
Some 10 years ago I had the honor to coach a scout for his Eagle project. It was hard to contain my excitement when the scout asked if he could do a woodworking project. Another member of our scout group suggested that we build birdhouses and contact a local Audubon Society member to get guidance and to be the project sponsor. The project developed from that point on, and soon a group of young men, young women and several adults began the construction of 150 kestrel nesting boxes. The kestrels were struggling in Florida at that time due to destruction of their habitat by fires. At the completion of the project, many of the youth were able to see the boxes they made mounted some 30 to 40 feet above the ground on power poles. The following year, the sponsor reported that many of the boxes had been used by nesting kestrels and that the project had been a major success. A year or so later, we found ourselves working on another project for our sponsor: blue bird boxes.
Currently, we’ve decided to build a blue bird box for a blog project. I hope the information we share here will encourage woodworkers to seek out their area’s local needs for bird nesting boxes, and will participate when possible.
On the Cranmer Earth Design Information website you can find an interesting history of birdhouses. The use of man-made birdhouses goes back as far as the 15th century. Materials used for birdhouses ranged from baskets to bark to pottery. When English immigrants reached the eastern coast in the 18th century they found that Native Americans were making bird houses out of birch bark. The Native Americans saw a need to bring birds to their area, and recognized that birdhouses could help accomplish this goal. Europeans built birdhouses to collect eggs or trap birds. Early American settlers wanted to attract birds for insect control.
So why do we build birdhouses today? Birdhouses can help offset habitat destruction by either natural or man-made means. It’s interesting to note that we build birdhouses for birds who do not naturally build freely supported nests in trees or structures, but look for cavities to nest in.
The birdhouse construction for our blog project follows the recommendation of the Audubon sponsor we used on earlier projects. It also follows fairly closely the recommendations outlined in the website www.nabluebirdsociety.com . This website provides the dimensions used in this project, specifically the size recommended for an Eastern blue bird.
The hole size and location accommodates the habit of the blue bird to fly directly into the birdhouse. There is no perch, because one is not needed, and a perch would provide predators a platform for entering the birdhouse. The wood used is untreated cedar (treated lumber should never be used). It was also our impression that, for at least these bird types, the house should not be painted. One side of the box is hinged, to open for periodic cleaning.
In many cases other animals may use the box when the birds are not nesting and their nesting material needs to be removed. A removable nail is used to lock this side in a closed position. This side is also designed to leave a gap just under the roof’s edge for ventilation.
Another side is also cut to assist ventilation. The floor of the box is notched for drainage, and slightly elevated from the sides of the box to help keep the interior dry.
It is also recommended that a ¼ inch groove be cut underneath the three exposed edges of the roof to prevent rainwater runoff from following the edge of the roof and curling back on the nesting box walls. The diagrams do not show it here, but it is also a good idea to cut a series of grooves on the inside face of the front side of the box. This is better illustrated in the construction photographs. The grooves provide a “toe hold” for the bird fledglings to climb out of the box.
When the nesting box is completed, it can be mounted on a pole or fence post four feet above the ground, in an open area. The website above gives specific positioning guidance for various types of bird houses. Our Audubon consultant suggested mounting the blue bird boxes on a post in a location with bushes about 10 feet in front of the box. This provides an opportunity for the fledglings to practice flying back and forth from the bushes to the box.
It isn’t always easy to insure that the location you pick will be free from predators such as cats, snakes or raccoons. The website above provides some guidelines for adding structures to the birdhouse or support to protect against predators.
For our project, we selected cedar as the construction material, specifically nominal 1×6 cedar planks. A four foot length will provide enough wood to make all but the roof. A 1×10 board is needed for the roof, but if you are only going to make one birdhouse, you can purchase some extra 1×6 and glue up a panel for the roof. This is what we did, since we had extra 1×6 boards and no 1×10’s. We used Titebond 3 glue since this joint would be exposed to the weather.
You’ll find that for some other box types, the back board for the box not only extends below the bottom of the box but also above the roof. This expedites attaching the box to a pole or other structure. This was the case for the kestrel boxes we built. In the case of the kestrel boxes, the roof butts up against the back board, leaving a seam where water could leak in. To prevent this, a sealant was run along this seam.
The construction of the box calls for galvanized nails. We found during the assembly of the 100 plus birdhouses that it was quicker to apply Titebond 3 glue to the joints and then use a pneumatic crown stapler to hold the joints together while the glue dried. This method seemed to hold up as well as using galvanized nails. The main reason we chose the method we did, was because we had several young people doing the construction and driving galvanized nails into the cedar with a hammer proved to be a challenge, unless we predrilled the holes. The cedar was very prone to splintering.
Here’s a little you-tube of the nesting blue bird box build:
The cedar boards from the big box stores could be easily cut to size with a chop saw. It would be recommended to use some kind of jig to nip the corners off the floor piece, to keep your hands well away from the chop saw blade. The hole for the entrance was drilled with a Forstner bit. A jig was also used to cut the grooves on the back side of the front wall. The depth of cut was set on the chop saw to 1/8 inch, and the board was fed by hand as the chop saw was repeatedly lowered onto the board.
If you’d like to provide some housing for our feathered friends, get into your shop and chop some wood! And as always, focus on what you are doing, and be safe!