House not always great nest

Don’t be fooled into thinking just any birdhouse will do. Actually, biologists and wildlife preservationists prefer the term “nesting box” to “birdhouse” because birds live in nests – not houses – and because some “birdhouses” on the market are for purely decorative uses only.

So before you get the hammer out, you should do some research.

One first step could be to get the Washington Department of Fish and Wildlife’s $5 Backyard Wildlife Sanctuary packet. It has tips for how to construct birdhouses for common regional birds: chickadees, nuthatches, flickers, bluebirds and wrens.

Normally these birds find dead-tree cavities offering secluded nurseries. An artificial nest – a birdhouse – can substitute for natural homes lost when dead trees are removed. In turn, nesting birds eat insects that can harm your trees and bushes.

Howard Ferguson, the department’s district wildlife biologist, says he most often hears the question, where should a birdhouse go?

“From research, it has been shown that a southeastern exposure is the best – not too hot and not too cold,” he says. “There are exceptions. Bluebirds often like theirs oriented out toward a field.”

Ferguson says people should consider birdhouses as temporary fixes.

“Leave those snags on your property – either dead or dead topped trees,” he says.

Birds need a clear flight path to any birdhouse, and it should, of course, be placed out of predators’ reach.

The size of the entrance hole is crucial.

The Backyard Wildlife Sanctuary packet states that if the hole is too small, the desired bird won’t be able to enter, and if it’s too big, undesirable wildlife – house sparrows, starlings, squirrels and cats – can get in and harm or evict the birds.

Generally, house sparrows can’t enter if a hole is less than 1 1/4 inches in diameter, and starlings can’t if it’s less than 1 3/4 inches.

If possible, place a newly constructed birdhouse outside in the winter to air out, with netting over the hole. If you put one out now, it may still be occupied or you may have to wait until next year.

Remember to build your birdhouse with a hinged roof so it’s easy to clean out. Cleaning is important, as it reduces the spreading of parasites and diseases.

The West Valley Outdoor Learning Center recently held a birdhouse building session for kids, says Brian Gautreau, an Americorps member at the center.

“We focused on Western bluebirds,” he adds. “The Audubon Society worked out for us the difference needed in hole-dimensions between mountain and Western bluebirds. It is about a 16th of an inch difference, but apparently that’s important.”

Pine can work as building material, but cedar or redwood is better.

And don’t add a perch on the house.

“If you have a perch, evasive birds such as starlings and house sparrows can kick a bluebird out,” says Gautreau, and that sort of defeats the purpose.