Hang a Bluebird Nesting Box
Eastern and Western Bluebirds Like to Nest in Birdhouses
Bluebirds, found throughout most of North America, need places to nest and they'll use a nesting box if it's in the right location and has the right features.
Bluebirds are seen virtually everywhere in North America, although they are rather rare in the middle of the continent, in the northeast, and in the Canadian north above Lake Superior. The Eastern Bluebird (Sialia sialis) occupies the eastern half of the continent, while the Western (Sialia mexicana) and Mountain (Sialia currucoides) Bluebirds occupy the west. The range of the Mountain Bluebird goes all the way to northern British Columbia and, rarely, this species is even seen in the Canadian Yukon and Alaska. All three species extend into Central America and the Eastern Bluebird also occurs in Bermuda
Attracting Bluebirds
The best way to attract bluebirds is to provide nesting sites: all three species have declined because of a loss of good places to nest. Because they nest in cavities, they rely on large old trees, a resource that has steadily declined over the years as forests have been logged and managed. In addition, bluebirds have had to compete for natural nest holes with other native cavity nesters such as flickers, Tree Swallows, and House Wrens, and with introduced species, particularly House Sparrows and Starlings.
Apart from available nesting sites, features that will convince bluebirds to stay include:
- Food—bluebirds eat a variety of berries, insects, and insect larvae, and will visit garden bird feeders for dried fruit, mealworms, suet, or peanut butter. Plant berry producing vines and shrubs, if possible, and supplement with feeder food. In winter, meal worms are especially popular.
- Water—natural water features are perfect, but bluebirds will also readily use a birdbath.
- Mixed habitat—bluebirds like to nest in cleared spaces but with open woods nearby. The Mountain Bluebird lives in very open habitat with sparse trees.
- Nesting materials—bluebirds build nests with materials such as fine grass, moss, animal hair, feathers and pine needles.
Bluebird Nesting Boxes: Design, Dimensions, and Features
A bluebird will nest in a birdhouse of roughly the same dimensions as a chickadee nest box, but bluebirds need a larger entrance hole. Ideal dimensions and features for a bluebird nesting box are:
- An entrance hole 3.8cm (1.5in) in diameter, located 15.5 – 25cm (6 – 10in) above the floor. If Mountain Bluebirds are a possibility, make the hole 4cm (1.56in).
- A 10.2cm (4in) square floor.
- A height of 20.5 – 30.5cm (8 – 12in).
- Drainage holes in the floor so that water can get out and air can get in.
- Ventilation holes at the top, protected from rain.
Bluebird Nesting Box Location
Bluebirds like to nest in open areas—a hole in a fencepost is a typical location. When locating a bluebird birdhouse, keep a few things in mind:
- An ideal site is near a wooded area but open on all sides.
- Face the nest box away from the prevailing winds for shelter.
- The box should be between one and two metres above the ground.
- Nest boxes are sometimes raided by predators: a smooth pole or a post with a baffle below the box will help keep squirrels, raccoons, etc. away.
- Have the nesting box in place by the end of February—bluebirds start nesting in March.
Eastern, Western, and Mountain Bluebirds all face challenges in finding good nesting sites: although they are doing better due to nesting boxes, you will be helping even more if you can attract them to nest in your yard.
Related Content:
Garden Plants that Attract Birds
Sources:
Attracting Birds. Woodier, Olwen. Pownal, Vermont: Garden Way Publishing. 1981
Birds of North America. Kaufman, Kenn. New York: Houghton Mifflin, 2000.
“Eastern or Western Bluebird Nestbox.” North American Bluebird Society.
"How to Attract Bluebirds to Your Yard." The Back Yard Birder
