Everyone loves bluebirds, and for good reason. They are beautiful to look at, faithfully provide for their families, and eat thousands of insects that might otherwise damage our gardens. However, a lack of nest sites for these cavity-nesting birds has caused a serious decline in their numbers. If you, like me, would love to have a pair of bluebirds sharing your yard, it helps to know a little about what the birds prefer. How can you make your yard more bluebird-friendly?

Bluebirds prefer to live in trees next to open fields. They perch and nest in the trees, and search for insects in the grass nearby. You can find Eastern and Western Bluebirds in orchards or forests next to meadows, farm fields, or grasslands.

Preferring cooler summers, Mountain Bluebirds live in grasslands and sagebrush next to forests of conifers, aspen, scrub oak and mountain mahogany. They are found in the Rocky Mountains from Colorado and Utah all the way to Alaska.

These bluebirds don’t mind disturbed habitats, and will move into areas that were recently logged or burned. Thus, their populations are increasing in the Pacific Northwest, where much logging occurs. (Other bird species that prefer old forests are decreasing for the same reason.)

Bluebirds do not eat seeds. They mostly eat insects (especially caterpillars, grasshoppers, beetles and bugs) and spiders. They will eat berries, too. From late summer to early spring, insects are hard to find. Western and Mountain Bluebirds eat juniper and mistletoe berries during the winter. The birds are important to these plants because they spread seeds to new places. Where the birds spend the winter is determined by the location and abundance of these fruits (especially juniper berries).

Often bluebirds find their bugs on the leaves of bushes and trees. Frequently they will sit on a low perch, such as a fence post, from which they swoop down on their prey. They briefly land on the ground to grab it in their beak before returning to their perch. This behavior is called ground-sallying. If no perch is available, Mountain Bluebirds are able to hover in midair, searching the ground for prey or nabbing flying insects.

As a good host or hostess, you can encourage insects in your garden. Don’t use toxic pesticides. Be willing to put up with a few chewed leaves. Many bluebird aficionados even purchase meal worms to offer their guests.

Remember that berries also make up part of the birds’ diet, especially in winter. Consider including a few junipers in your landscaping (make sure the plants are berry-producing females).

Water attracts all kinds of wildlife, and bluebirds are no exception. A shallow birdbath with a rough-textured surface for firm footing will be appreciated year-round. Running water is even better, if you can manage it. The sound will attract birds that might miss a quiet pool.

Perhaps the most useful thing we humans can do for bluebirds is to provide some nesting boxes. While they do not excavate their own cavities, bluebirds eagerly take advantage of abandoned woodpecker holes. If you don’t happen to have any dead trees in your yard, you can put up a nest box or two. Make sure they’re properly constructed for the species of bluebirds you have locally.

Then situate it properly. While most of us don’t live in orchards, forests, or meadows, we can remember to nail the box onto a fence post or tree trunk facing the lawn. Perhaps the birds won’t be too choosy.

Next week, I’ll talk more about nesting boxes, and why bluebirds, in particular, benefit from their use.

For more information: Cornell Lab of Ornithology, North American Bluebird Society, Sialis