CORVALLIS, Ore. — It would be nice to say, “Hang a birdhouse and they will come,” but attracting wild birds to nest in your yard isn’t quite so easy.

Now is a great time to get boxes up — nesting for many species runs from mid-April through the end of July.

Don’t get discouraged if your nesting box doesn’t draw birds the first year, said Dana Sanchez, wildlife specialist with the Oregon State University Extension Service. Move it to a new spot and put up more than one to give birds a choice.

“The entrance diameter is really crucial so that target species can get in, but also to diminish the opportunity for birds to be attacked by predators and competitors,” Sanchez said. “Non-native birds such as house sparrows and starlings are notorious for taking up residence in nest boxes intended for native birds. And some native birds will bully out other native birds.”

Don’t hang it and forget it. Check the box regularly to see if birds are being stalked by predators. If so, add a wooden block with the same-size hole to create a short tunnel that’s harder for other birds, squirrels, rats and cats to reach through. Other deterrents include a metal collar around the tree or post and various baffles you can buy or build. As always, keep cats indoors.

Snags are superior habitat — when safe

In addition to the enjoyment of watching adults ferry food and nesting material — and then seeing fledglings appear — birdhouses help mitigate habitat loss, said Nicole Strong, a former Extension forester and now a regional director in Central Oregon. Birds prefer dead or dying trees (snags), but many homeowners remove them for safety or aesthetics.

“If it’s not a hazard, leaving up dead trees gives great habitat for wildlife,” Strong said. “As they decay they provide cavities for birds. And once the trees crumble and become downed logs, they provide food for insects, grubs and other wildlife. Sick and dead trees are healthy for the forest; they’re part of the ecosystem.”

If you keep a dead tree, reducing height and removing most branches can lower risk. Otherwise, well-placed birdhouses are a good alternative.

Build to spec with OSU’s guide

You’ll find step-by-step plans, placement advice and box dimensions for about 18 Oregon cavity-nesters — including house wrens, chickadees, woodpeckers, northern flickers, purple martins, barn owls, nuthatches and western bluebirds — in the OSU Extension guide The wildlife garden: Build nest boxes for wild birds.

Materials, cleaning and maintenance

If you make or buy a box for one of Oregon’s 45 cavity-nesting species, skip perches that can aid predators. Plain wood boxes tend to be favored over brightly painted ones. For longevity, use untreated cedar or redwood; metal can overheat.

It isn’t necessary, but you can line the box with wood shavings or chips (not sawdust, which mats and holds water). Clean boxes in fall or winter with warm water. Choose designs assembled with screws so you can partially disassemble them for cleaning.

Habitat beyond the box

“Remember that a nesting box is just one piece of habitat,” Strong said. “They need safe access and food and water nearby. Bird feeders can be a wonderful aid, but they must be maintained. Be consistent. Don’t put them out and then take them away.”

Adding bird-friendly plants and layered shrubs for shelter helps, too. A simple bird bath provides critical water.

Previously titled Nesting boxes invite birds to hatch babies in home gardens