Nest Boxes for Birds

Placement

When
Some birds begin courtship and nesting activities as early as February, but most birds select sites from late March through May. This is also the time when most migrating birds return to Washington. Nest boxes can be set out as soon as you notice new birds arriving.

However, newly made bird houses need to be set out in winter to weather and air out. To prevent house sparrows and European starlings from setting up house in them before other species of birds arrive, plug the entrance hole until you observe the preferred species.

Where
The nest box should be somewhat concealed, in partial shade and placed where predators can't get to it. Check to be sure the birds have an adequate, clear flight path to the entrance hole. If possible, the entrance should face away from the prevailing wind. It usually helps to put the box on a habitat edge: between a group of trees and low-growing bushes, or between bushes and an open meadow, lawn or water.

All nest boxes should be firmly attached to a support post or a tree. When attaching a nest box to a live tree, use lag screws and washers. These screws can be loosened each year, preventing the back of the box to break and allowing the tree to grow without any deformities.

How Many
A good rule of thumb is to allow 1/4-acre between most bird houses. Because most birds are territorial, the average-sized yard will probably only hold one nesting pair of a particular species. Territory size varies among birds - tree swallows require only several feet of space, robins need less than half an acre, while chickadees and nuthatches usually need several acres. Other birds, like purple martins and wood ducks, don't defend territories. That's why martin houses are the "apartment" type.

Territories change from year to year, so a well-designed and well-placed nest box will eventually be used if birds you're trying to attract are found in your neighborhood. If a nest box isn't used for some time, birds nesting nearby may be defending the area from other birds of the same species. It may help to set out several nest boxes (for certain species) in different places so birds can pick the best site. If you don't want house sparrows or European starlings to be your next tenants, be sure to take down unused houses after the desired birds have settled in.