Even though we have had some rough weather lately, this winter didn’t seem so bad to me. Now that the weather forecast is looking positive and the days are getting longer (this month we gain about 75 minutes - I am embarrassed to admit that I check this frequently during the winter because it helps me get through the winter doldrums), it is a good time to think about wildlife habitat projects. Sometimes landowners and homeowners can be overwhelmed by all the different ways they can help wildlife on their property. An easy project that is also fun to build and place on your property is a nest box. You don’t want to wait much longer. Erect your nest box well before the average start of the nesting season (most birds start in mid-April, but some start sooner). Some species will set up their nesting territory 3 to 4 weeks prior to egg laying.
Many species of native birds and mammals will utilize nest boxes. When we put out a nest box, all we are doing is replicating what nature already provides with cavities in both live and dead trees. Woodpeckers are primary cavity users because they create their own. Other birds and mammals are secondary cavity users because they use what is already there – either those that occur in older, dying trees or those that are created by woodpeckers. Installing nest boxes in areas where cavities are likely scarce such as urban environments or young woods may be particularly beneficial.
- Use quality materials that are weather resistant. Exterior grade plywood and lumber are good choices. Cedar and other rot-resistant woods are best. Avoid using treated lumber and metal.
- Avoid painting or staining inside nest boxes. Painting the outside can prolong its life and may be attractive for some species (white for purple martins, for example).
- The roof should be sloped to allow water runoff and should hang over the sides.
- Drill at least four 3/8-inch drainage holes on the floor.
- The roof or one side should open to allow easy access for cleaning.
- Avoid perches. Natural cavities don’t have them and neither should your nest box. Perches also allow European starlings and English house sparrows, non-native invasive species, to harass native cavity nesters and take over a nest box.
- Near the top of each side, leave gaps or drill 5/8 inch holes (at least 2 per side).
- Remove perches from wildlife nest boxes like the bluebird box pictured here. Perches allow undesirable birds to harass native cavity nesters and take over a nest box.
More tips on design, such as nest box specifics by species (dimensions, hole size and placement, box placement, and location), maintenance, and problem species, can be found in our Nest Boxes for Wildlife publication.
Brian MacGowan, Extension Wildlife Specialist
Department of Forestry & Natural Resources, Purdue University