Nesting Box

Setting up a nesting box in your yard can provide an essential nesting area for the members of many species of birds. It is also a great way to provide wildlife a place to raise young, one of the four things you need for your outdoor area to qualify as a National Wildlife Federation Certified Wildlife Habitat.

While many species are able to hide their nests in dense foliage or grassy meadow areas, many others require holes for nesting. Some birds, such as woodpeckers, can excavate their own nesting cavities in dead or decaying trees. Others depend on the abandoned nesting holes or natural cavities formed from fallen branches for places to build nests.

Recently, however, an increase in development and removal of damaged and dead trees has left many cavity-nesting birds with fewer natural places to raise their young. In addition, invasive birds, such as the European starling and the house sparrow, compete with native bird species for the use of the remaining cavities.

Adding a nesting box to your habitat will not only benefit native bird species, it will also give you an opportunity to monitor and enjoy birds.

Building or Selecting a Nesting Box

Although most birds prefer natural cavities for nesting, with the correct design a nesting box can serve as a good replacement.

There are numerous types of bird nesting boxes available commercially. Each box contains different features and is targeted at a particular bird species. But not all nesting boxes are created equal. There are several features to consider when purchasing or building a nesting box.

Check that the box is well constructed and contains these basic features:

Constructed of natural untreated wood (pine, cedar or fir)
Lumber for walls that is at least ¾ of an inch thick to provide insulation
An entrance hole of the appropriate size to allow desired birds to enter but keep larger birds out
An entrance that is the correct distance from the floor to accommodate the nest
An extended and sloped roof to keep the rain out
A recessed floor and drainage holes to keep the interior dry
Rough or grooved interior walls to help fledglings exit
Ventilation holes to allow the interior to remain cool
A side or top panel that opens to allow easy access for monitoring and cleaning
No outside perches, which aid predators and other harassing birds

It is also important to make sure that your box incorporates features preferred by the particular bird species you hope to attract. These features include the entrance hole size, the height at which the box is posted, and the type of habitat surrounding the box. When purchasing a nesting box, research the physical requirements of the species that you hope to attract and make sure that you are investing in a functional, rather than ornamental, birdhouse. Check out the Birdhouse Network of the Cornell Lab of Ornithology for more specific information on species preferences.

Where to Place Your Nesting Box

The habitat available to you will be the primary factor determining the type of birds you can attract for nesting. Here are a few things to consider:

Make sure that you place birdhouses in a location where the target bird species is likely to reside. Before placing your box, research habitat, nest height and direction preferences for the species.
Avoid putting nesting boxes in areas where herbicides and pesticides are used. Not only do these chemicals decrease insect populations--the primary food source for most cavity-nesting birds--but they can also harm birds directly.
The box can be mounted on a tree or a pole. Placing the box on a pole with a predator baffle to protect the birds is often more successful. Make sure that the box is attached securely enough to withstand severe weather and winds.
Take into consideration the direction your box is facing and how much direct sun it receives. Many birds will reject boxes that face due west, for example, because the box may stay too hot.

When to Set Up Your Box

Make sure your nesting box is in place well before the arrival of breeding season.

In the southern part of the country, boxes should be in place no later than February.
In the northern regions, boxes can be placed outside before mid to late March.

This will give birds a better chance of finding and using your box, and it may even be used for winter cover if put outside earlier. Don't be discouraged if birds don't find the box in the first season; sometimes it can take a few years for the birds to find the box.

Monitoring and Cleaning Your Box

Once breeding season begins, monitor your box for activity. You can enjoy watching adults quickly dart in and out as they build their nests or feed hungry nestlings. If your box is first discovered and used by invasive bird species consider removing the nest. Doing this regularly will likely encourage the bird to move to another location and free the box for use by native species.

Once eggs have been laid you may want to monitor the progress of the nest. Lightly tap on the box before opening the panel to allow the adult bird to leave. So as not to become a nuisance, limit your viewing time to less than a minute once a week. Keep track of the progress of the nestlings. This way once they have fledged and the box is no longer in use it can be cleaned. Some birds will not use cavities with abandoned nests in them, and removing the debris cuts down on ectoparasites for the next set of nestlings. If you remove the nest in a timely fashion you could enjoy two to three broods per season!