Different birds require different sizes — check our chart
Watching the birds that stop by for birdseed is only part of the fun of a wildlife-friendly yard. There’s even more enjoyment to be had when you provide them with convenient places to nest. A well-placed birdhouse gives you the opportunity to observe their family life, from the parents’ nest-building to feeding their young. With some luck (or a motion-activated camera), you might even see the fledglings leave the nest.
There’s another, more important reason, for providing birdhouses in our yards. About 85 species of birds in the U.S. nest in cavities they excavate in dead or dying trees, or make use of existing openings in them. In the city, such trees are usually cut down and hauled away, leaving suitable nesting structures in short supply. Outside the city, it isn’t any better; habitat destruction is causing some bird populations to fall.
No single birdhouse works for all birds. You can see from the chart below that birds who are willing to nest in birdhouses are particular. They want the birdhouse to duplicate the conditions they would seek in nature. Each species looks for a birdhouse that fits within a narrow range of specifications. For example, you’ll never coax a Robin to nest in an enclosed box of any size or shape, but a well-placed “shelf” might be used year after year. Gregarious Purple Martins prefer to nest in an “apartment building” along with many other families. Bluebirds like a deep birdhouse and woodpeckers an even deeper one. The size of the entrance hole in birdhouses plays a role, too, as you might assume. The small opening in a wren house, for example, helps to protect the wrens from predators, as well as keeps larger birds from taking it over.
Most hardware and general merchandise stores carry birdhouses specifically designed for certain birds. You can definitely find them at birdseed stores and online. Discount stores will carry inexpensive birdhouses, which usually prove to be examples of getting what we pay for: unsuitable wood for outdoor use, staples instead of screws, plastics (which don’t “breathe,” as wood will), and lack of an opening for easy cleaning.
*Top photo: Eastern Screech Owl babies (© Carolyn Russell)