Eastern bluebirds (Sialia sialis) like to nest in natural cavities made by woodpeckers in oak or pine trees, typically no higher than 50 feet from the ground. Lacking natural cavities, bluebirds will nest in houses. Traditionally, bluebird houses had round openings 1 1/2 inches in diameter and a 6-inch square nesting area. Lately, designs have changed in order to keep sparrows and starlings from using bluebird houses.
There are three basic types of bluebird houses: traditional, Gilwood and Peterson. Traditional houses can be constructed from a 1-by-6-inch, 5-foot-long board. The floor size is 5 by 5 inches, the height anywhere from 8 to 12 inches, with a 1 1/2-inch hole opening 6 to 10 inches from the bottom.
Like the traditional box, the Gilwood is rectangular but smaller inside. The floor is 4 by 3 inches and the box is 5 inches deep. The Gilwood has a half-circle opening with a wire across the top to keep out avian intruders. The Peterson nest box is triangular with the base at the top, the point cut off at the bottom and an oval opening. The steeply angled top of the box measures 10 1/4 inches and the back is a foot tall.
- Cornell Lab of Ornithology: All About Birds: Eastern Bluebird at a Glance
- Georgia Department of Natural Resources: Out My Backdoor: What's the Best Bluebird Box Design?
- U.S. Geological Survey: Northern Prairie Wildlife Research Center: Attracting Bluebirds and Other Cavity Nesting Songbirds in North Dakota
- Missouri Department of Conservation Online: Build a Bluebird House
- Wild Bird Watching: Building Bird Houses For Wrens, Bluebirds and More
- New York State Bluebird Society: Peterson Box
- National Wildlife Turkey Federation: Get in the Game: How to Build a One-Board Bluebird House
- Audubon Society of Omaha: The Bluebird Box: The Gilwood Nest Box
- Michigan Bluebird Society: Nest Box Basics
- Virginia Tech: Powell River Project: A Study to Determine the Preference for Nesting Box Design of Sialia sialis (Eastern Bluebird): Comparison of the Traditional Nesting Box And the Peterson Box