Gardening Columns

As I was writing this column, a blue flash outside the window
caught my eye.

I've Got the Blues -- Bluebirds, That Is

First published on garden.org on March 16, 2006, by Suzanne DeJohn

Last weekend a male and a female bluebird sat side by side on a branch next to our bluebird house. She'd flit to the house, pop her head in, then rejoin her mate on the branch. "Honey, what do you think?" "Well, it's an awfully nice house but I'm not so sure about the neighborhood."

Streaking between trees like little slices of the bluest summer sky, bluebirds make welcome gardening companions and a nice diversion from the sometimes tedious tasks of springtime weeding and mulching. If you want to enjoy their company, now's the time to set up a bluebird house.

A Bluebird Primer
The eastern bluebird was once one of the area's most common songbirds. During the last century, populations declined -- by as much as 90 percent in some areas -- due to a number of factors, including a string of unusually severe winters, habitat destruction, and the widespread use of pesticides that killed off not only the birds' primary food -- insects -- but also the birds themselves. Conservation efforts have resulted in a rebound of bluebirds, so that now they are no longer a rare sight.

Insects make up about two thirds of the bluebirds' diet; the other third consists of berries consumed during the cold months when insects are scarce. Because the birds rarely damage cultivated crops and consume oodles of pest insects, they are very beneficial to farmers and gardeners. Unlike bluebirds from more northern habitats, bluebirds in this region stay here year-round and don't migrate south for the winter.

Putting Out the Welcome Mat
Understanding the species' feeding and nesting preferences will help you select and site your bluebird house. Eastern bluebirds favor relatively open landscapes with occasional trees. You won't find them in dense woods, nor in vast treeless expanses. Fortunately, most suburban landscapes suit bluebirds just fine. In the wild, bluebirds nest in tree cavities and old woodpecker holes. However, two non-native species, European starlings and house (English) sparrows, have flourished and commandeered many of the nesting sites formerly used by bluebirds -- another reason for the bluebirds' decline and why it's important to provide manmade nesting boxes.

Here are a few key considerations to keep in mind when constructing or purchasing a bluebird house.

1. The hole should be 1-1/2 inches in diameter. No, bluebirds can't measure. But larger holes will invite bluebird competitors.

2. The box should open easily for cleaning.

3. It should have a waterproof roof and small holes in the bottom for drainage and air circulation.

4. Boxes should not have perches. The bluebirds don't need them, and perches invite predator birds that damage eggs and hatchlings.

5. Wooden nesting boxes may be left unfinished; however, in warm regions it's best to paint the outside a light color to minimize overheating. Leave the wood bare on the inside.

Install the box 4 to 5 feet above the ground in an area with low-growing ground cover or mown grass. Ideally, it should be near a tree so newly fledged birds have a place to perch. Mount the box on a predator-resistant post in areas with raccoons or cats.

It's a little ridculous, I know, but somehow I feel like a better person for having bluebirds nesting in my yard. If such wonderful little bundles of color and energy choose to spend their time near me, then I must be doing something right.