Snowbound by two feet of snow with more on the way, a patch of blue sky turns my thoughts to eastern bluebirds. Although the nesting season is still about seven weeks away, now is a good time to plan.

The easiest way to attract bluebirds is to place nest boxes in suitable habitat -- open areas with scattered trees and few houses. Pastures, hay fields, cemeteries and golf courses are good places. Males sing from treetops, and both sexes hunt from elevated perches. They watch the ground for grasshoppers, beetles and other insects, capturing prey by flying to the ground, pinning the insect with their feet, and killing it. Then they return to the perch for the meal. This time of year, bluebirds eat fruits and berries almost exclusively.

Hang nest boxes 4 to 5 feet above the ground on a post protected from below by a predator baffle. The baffle is essential because without it a nest box eventually becomes a feeder for raccoons and rat snakes.

A basic box measures 4 or 5 inches square (inside dimensions) and is 10 to 12 inches high. The entrance hole should measure precisely 11/2 inches in diameter and be placed about an inch from the top. This hole size excludes bigger-bodied starlings from using the boxes. Extend the roof at least three inches beyond the front of the box to protect the entrance from driving rain. The front or side should flip open for easy cleaning. For detailed bluebird box plans, visit www.nabluebirdsociety.org/eastwestbox.htm.

If you're not a do-it-yourselfer, bluebird nest boxes can be bought at wild bird stores, nature centers or through the Pennsylvania Game Commission. To order, call 888-888-3459 or visit www.pgc.state.pa.us and click on "Howard Nursery" from the "General Store" drop-down menu and then select "Wild Homes Order Form." Bluebird nest boxes are $7 plus shipping.

Bluebirds begin searching for and exploring cavities in January and February, but nest building doesn't begin until late March or early April. By hanging nest boxes now, they become part of the landscape and are more likely to be used.

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