- Topics started 43
- Replies 184
- Total Posts 227
My boxes have two holes. The idea is that bluebirds can defend these boxes. They are not sparrow resistant but allows an escape for adult bluebirds to take the fight outside of the box. Linda Violett did a great deal of field research on this idea with great success.
Linda Violett dual holed mansions
- This reply was modified 5 years, 6 months ago by phillyblues.