The Wild Side: Constructing a proper birdhouse
My nephew emailed me with some questions about constructing a birdhouse for a college art class. This is not unusual-every spring I get a phone call or two about bird houses, wood duck houses and bird feeders.
Bird feeding is the number two hobby in the United States, after gardening, so it stands to reason that so many people are interested in learning more. In a normal year, we would expect that birds would just be starting to move into erected bird houses-but this is not a normal year. When I was watching the boys ride bike this weekend, I saw an eggshell on the sidewalk; it looked like a mourning dove egg to me.
I had to dig around and find my homemade chickadee birdhouse, yet to be unpacked from the move, and get it hung up. Mid-April is usually when they start nesting, but I may be behind the curve this year.
Designing a birdhouse seems easy enough-make an enclosure with a hole in it, and you’re done. In fact, nothing is ever quite that easy. Unfortunately, if you make a mistake with your design or construction, you could put the bird, and its nest, in danger. So, if you want to construct your own birdhouse, there are some important design components to keep in mind. When I work with students or volunteers, I recommend using wood. It is a natural, renewable material that allows little bird feet to grip. More importantly, it provides the level of insulation that keeps the bird and nest the warmest in cool weather, and the coolest in warm weather.
Unfortunately, it is still not the perfect material-we have found birds that packed into a bird house trying to escape the cold, only to die because they got too cold, or could not get back out because the walls were too smooth. So, if you are not using wood, make certain that the material provides at least some insulation, and is not smooth inside-or you will need to attach wire mesh, or make a little ladder going up to the hole.
The entrance hole is important. It has to be small enough to make the bird squeeze into it. If the hole is too big, nest raiders like squirrels, house cats and raccoons can get a paw inside and destroy the nest.
Do not put a little perch below the hole; the birds might use it, but nest raiders may use it as well.
One side of the house needs to open with the removal of a nail or screw, or in my case, a window clasp. You want to be able to clean out the nest once the young have hatched, and if an undesirable bird is trying to use the box, you can go in and remove material to prevent egg laying. One year we had a house wren that insisted on packing our chickadee house with pine branches, and I kept emptying it, before finally giving up.
Some houses open at the bottom, but if you open it while there are still eggs or young, there could be a problem. I recommend the bottom be firmly fixed, and have three or four holes drilled in it to allow water to drain out, and air to circulate. The roof should have an overhang that shelters the hole a bit, provides some shade and allows the birds to land on it.
My nephew decided to change to constructing a bird feeder for his project, which is understandable; after all, the art in constructing a birdhouse is to raise a healthy brood of birds. Appearance is second. Bird feeders, on the other hand, can be creative, versatile and attractive, as long as they can be properly cleaned and sanitized. There are lots of great birdhouse plans available. I most often refer to “Woodworking for Wildlife” by Carroll Henderson of the Minnesota DNR.
Jeremy Holtz is a wildlife biologist with the Wisconsin DNR in Rhinelander, and writes a weekly column in the Star Journal. To contact him, call (715) 365-8999.