Constructing a bird house can be a satisfying activity both when construction is complete and when you see birds successfully using it to raise their young.
In this episode of Wildlife Matters, the Masked Biologist shares some pointers for building a safe and successful bird house.
Every spring I get an inquiry 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 spring especially, we get an influx of birds hammering feeders in an effort to refuel after flying thousands of miles from their southern wintering grounds as they head to their breeding grounds here in the north. In a normal year, we would expect that birds would have started to move into erected bird houses—but this is not a normal year. Mid-April is usually when they start nesting, but from what I have seen, the April snowstorms have slowed things down at least somewhat. Chickadee pairs were just starting to scout cavities in the oak tree in my yard on Earth Day, and the warm weather seems to have triggered a renewed chorus of bird songs around the neighborhood.
Designing a birdhouse seems deceptively 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 because they 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 cute little perch below the hole; the birds might use it, but nest raiders may use it as well. Your birds will do just fine without it; you just might not get them to pose for as many cute pictures because they will land right on the entrance hole. One side of the house needs to open with the removal of a nail or screw, or in my case, the twist of a storm window clasp. You want to be able to clean out the nest once the young have hatched, if the nest is depredated or fails, or a bird or mouse dies in the box. Some houses open at the bottom, but if you open this kind of house while there are still eggs or young, there could be a problem. I recommend the bottom be firmly fixed and with three or four holes drilled in it. Holes are critical to allow water to drain out, and to provide air circulation. The roof should have an overhang that shelters the hole a bit, provides some shade, and allows the birds to land on it. You should hang the box in a location that makes it difficult for squirrels, cats, or raccoons to get to it. if you put it on a post, you can put a predator guard around the bottom of the box to try to reduce the chance of disturbance.
I have a chickadee nest box in my yard, and last year I was so excited when I saw a pair carrying nesting material into the box. The pair successfully hatched the eggs, and I watched the parents tirelessly hauling every bug they could find nearby and dropping it into the waiting mouths of hungry offspring raising a ruckus inside the house. Finally, I was able to watch them on jump day, as the parents coaxed the young out of the box into the oak tree across the driveway with enthusiastic vocalizations and the promise of a yummy bug. Then, just like that, they were gone. I hope they decide to return and entrust me with the care of another brood.
Striving to make new things familiar and familiar things new, this is the Masked Biologist coming to you from the heart of Wisconsin’s great Northwoods.