bluebird nest box

Even though the bluebird population has greatly decreased, the future can still be promising for them. The most important step we can take to help bring back the bluebird is to provide nesting sites by setting out a bluebird box or starting a bluebird trail. A bluebird trail is a series of bluebird boxes placed along a prescribed route. In areas where nesting boxes have been put up in suitable habitat, bluebird populations are increasing. Bluebirding is a great environmental, hands-on project that people of all ages can enjoy.

see http://www.nabluebirdsociety.org/gettingstarted.htm