Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: FRIDAY, March 1, 1991                   TAG: 9103010407
SECTION: EXTRA                    PAGE: E-4   EDITION: METRO 
SOURCE: PATRICIA C. HELD
DATELINE:                                 LENGTH: Medium

BLUEBIRDS MAKING A COMEBACK, NOW THAT THEY'RE FINDING HOMES

Since colonial times the bluebird has been one of America's favorites. Only found in North America, the Eastern bluebird inhabits the area east of the Rockies. It is closely related to the Western bluebird and mountain bluebird. All have similar habits and, unfortunately, have faced similar problems.

Around 50 years ago, bluebirds began disappearing at a steady rate. Studies indicated that there was a 90-percent decline in their numbers.

Why was there such a radical drop in the population?

Bluebirds are chiefly insect eaters. The use of insecticides destroyed much of the bluebird's primary food source. Severe winters added to the problem.

But an equally important reason for the bluebird's decline was the scarcity of suitable nesting sites.

Bluebirds are birds of the orchard and hedgerow. They rarely nest in cities and will not settle in heavily wooded areas. They prefer open spaces with little underbrush and a few trees scattered about. Pastures, old fields, golf courses and cemeteries are their favorite haunts. They nest in the cavities of dead trees, woodpecker excavations and decayed fence posts.

The development of open fields, the clearing away of dead trees and the replacement of wooden fence posts with metal ones began to eliminate many nesting sites. The bluebird became a victim of habitat alteration.

The house sparrow and starling complicated matters. Both of these birds are also cavity nesters and are aggressive enough to take over most available bluebird nest sites.

To complicate matters even more, the sparrow and starling are more adaptable than the bluebird. Able to nest in a variety of areas including those close to development, their numbers are not limited by the scarcity of nest cavities.

Now the good news. In recent years, thanks to many people's efforts, the bluebird has made a remarkable comeback. Man-made nest boxes have given the bluebird places to nest. Long stretches of nest boxes have been set up to form bluebird trails and the population has begun to grow again. As a result, we now find bluebirds throughout our rural areas.

Successful bluebird houses need to adhere to a few principles of design, construction and location, but the Eastern bluebird responds well to human assistance.

Nest boxes should be designed to foil predators and be placed in suitable locations. The entry hole should be 1 1/2 inches in diameter, to prevent starlings from using it. This hole should be placed 6 inches from the floor. (Note that no matter how closely a box comes to the ideal dimensions, the other cavity nesters sometimes move in. Don't be surprised to see tree swallows, chicadees and wrens setting up housekeeping in your bluebird boxes.) Bluebirds begin to look for a nesting site in early March, so now is the time to begin setting out your nest boxes. Choose open fields and place the boxes facing away from prevailing winds, about 3 feet to 5 feet off the ground. Set boxes about 25 feet to 50 feet apart and about 25 feet from trees. Avoid placing boxes near buildings.

Each year the nest boxes should be cleaned out. Late winter is the best time for this chore, especially since winter is the dormant time for wasps, which will often inhabit these boxes. After cleaning, be sure the box is closed securely. If you can open it easily, you can be sure predators can, too.

Their nest inside the box will be constructed of dry grasses and needles. Three to seven eggs are layed and incubated for about 14 days. The parents care for their young until they fledge and learn to fend for themselves. In one season, a pair of birds can have up to three broods.

Recently, John Angell of Penhook sent me plans for a bluebird house that he found in The Southeast Farm Press. The plans are simple and require no lumber ripping or large drill bits. For a copy of these plans, send a self-addressed, stamped envelope to the address below.

Patricia Held will respond to readers' questions on the plant and animal wildlife in the region. Mail inquiries to: Patricia C. Held, P.O. Box 65, Goode, Va. 24556.