A walk in the woods: Installing a bluebird house

Published 12:00 am Saturday, April 25, 2009

By Melody Bell Wilkes
For the Salisbury Post
It’s always a pleasure to drive on a country road and spot a pair of bluebirds flying through the pasture or see them perched on a high wire.
Male bluebirds grace nature’s palette with royal blue plumage and a rusty red breast standing out in contrast to the greens and browns of their surroundings. Females are duller in color yet still have tinges of blue on their tail and the young sport a speckled gray breast.
Over the years, finding suitable nesting sites for bluebirds has gotten harder. Bluebirds are cavity nesters and seek old trees for holes to build their nest of woven grasses and pine needles. Our landscape today has changed and old trees have been cut down, land has been cleared for housing, shopping centers and other developments. Competition for available natural nest cavities is high as bluebirds must compete with other cavity nesters such as House sparrows and European starlings that are more aggressive and typically out-compete the timid bluebird.
Although the bluebird population has decreased overall in its range, we can help bluebirds by providing houses designed to their specifications and help eliminate the threat of predators and competitors.
To start your bluebird house, follow these simple guidelines and enjoy many nesting seasons to come.
Many designs available, but if you would like to make your own, these are recommended standards used by the North American Bluebird Society. Eastern bluebird houses should have a round hole of 1 1/2 inch without a perch (sparrows and wrens are attracted to perches). If the diameter of the hole is any larger, then other birds will occupy the space.
The nest box depth should be at least 7 inches from the bottom of the hole to the bottom of the box. The floor size should be at least 4 inches by 4 inches with drainage holes and recessed a quarter of an inch to prevent the floor from absorbing water. To provide shade, have a roof overhang of 3 inches. Ventilate with holes at the top of each sideboard with quarter- or half-inch holes. The house should be well ventilated, watertight, have drainage holes and easy to clean.
The best materials for construction are 5/8-inch or 3/4- inch exterior grade plywood or cedar. Do not use treated lumber because of its toxic content. A light color of exterior non-leaded paint or stain can be used. Avoid painting the inside of the box or the inside of the entrance hole.
Mount your bluebird house on a smooth round pipe. Coating the pole with grease can help reduce predators. Hardware cloth placed under the box can reduce snake predation. Avoid mounting the box on a fence line or trees since raccoons are known to walk fence lines and find the box.
Placement is important for a successful bluebird house since these birds are territorial. Open rural country where the box overlooks a field or pasture is best. There should be brush and scattered trees nearby for perching. Position the entrance hole away from prevailing winds and approximately 5 feet above the ground.
If you are establishing more than one bluebird house, make sure there is at least 125 to 150 yards in between boxes so bluebird territories don’t overlap.
Bluebirds lay four to five light blue eggs and their incubation time is 12 to 14 days. Nestlings remain in the nest 18 to 21 days before they fledge. Refrain from opening the box to observe the young since this will increase their chances of leaving the nest before they are ready. As soon as the birds have fledged, remove the bluebird nests or nests of other birds. Keep it clean for the next use.
Baby bird season is near. If by chance you find an injured or orphaned bluebird, or any wild animal, please contact your local wildlife rehabilitator that has been trained to deal with wildlife issues. For a list of wildlife rehabilitators in your area, call Animal Rehabilitators of the Carolinas hotline at 704-552-2329.
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Melody Wilkes is owner of A Walk in the Woods, an environmental education company that provides outreach wildlife programs. Contact her at 704-436-9048 or visit www.awalkinthewoods.us.