Want More Bluebirds? Here’s How

by Jill Peleuses

Ask any enthusiast about bluebirds, and most every one has a favorite story or experience to share. With its beautiful color and cheerful, warbly song, the Eastern Bluebird continues to be one of our most beloved songbirds. Although it can be found in our area any time of year, the bluebird was just recently a rare visitor. Thanks largely to grass-roots efforts, bluebird populations are on the rebound today.

Due to a series of factors, by the mid1950s the population of Eastern Bluebirds was in serious decline. Widespread pesticide use, the introduction of non-native species like the House (English) Sparrow and European Starling that compete with the bluebirds, and loss of nesting habitat all contributed to the plummeting bluebird population. Guided by groups like the North American Bluebird Society, citizenscientists and backyard birders began trying to support bluebirds by the late 1960s and by the mid-1980s the population had begun to rebound. The most significant factor in the recent population recovery is volunteerism—people putting up and monitoring nest boxes, spreading the word and encouraging others to get involved.

There are several steps one can take to help support the Eastern Bluebird, and one of the most effective is the creation and placement of suitable nesting boxes. The Eastern Bluebird is a cavity nester and naturally chooses dead trees to build their nests. As the human population increased and more land was developed, there were fewer choices available for nest-building. Providing a “Bluebird Trail,” or series of nesting boxes strategically placed to mimic the lost nesting habitat, can be of great help.

Nesting boxes make excellent homes because they can be placed in areas that can be maintained and safe from predators. Bluebirds are looking for a house that is situated in the most open space available. During nesting season these birds become very territorial. In order to protect their home, they stand on the roof of their house and look around at a 360-degree angle to make sure no predators are near. So houses located on freestanding poles with a predator guard or baffle tend to be the most successful. However, bluebirds may still choose a house that is placed on a tree or a fence post.

Bluebirds often return to the same nesting box year after year, so it’s important to maintain the boxes and to clean them routinely to minimize any mold, moisture or parasites that might affect future broods. It’s also possible to add a “nesting cup” to nesting boxes to make cleaning simpler.

Although this Carolina Chickadee has already established a nest in this bluebird nesting box, the approaching Eastern Bluebird will drive it away and take over the space for its own use.

photo by Chuck Carmack

Nesting behaviors can start as early as February and go all the way into August, with some pairs having three broods of chicks in a year. Not all bluebirds nest at the same time; some may not start their first nest until April or May. The female lays one egg a day for several days, then the eggs must incubate for about two weeks before hatching. Once hatched, the young will stay in the house for two to three weeks and the parents will feed them insects, mealworms and sunflower chips. After the birds have fledged and left is a good time to clean out the box; if done right away the parents may start building a new nest there within a week.

Another strategy for encouraging bluebirds is maintaining a year-round food and water supply—this can be in the form of native plant species or bird feeders. Bluebirds are primarily insect eaters, and planting or keeping native species in your area helps provide habitat for the insects that these birds need when raising their young. Native berries are a particular draw for the birds. Bluebirds will also eat insect suets, which are cakes of food that are high in fats and proteins. The main seed that they prefer are shell-free sunflower chips. They also love mealworms and will fill their beaks and take them into the bird house to the young. In winter the bluebirds are not as territorial and you may see multiple individuals eating worms together.

Many other birds enjoy the same diet, so if mockingbirds or others are scaring away your bluebirds, placing feeders in the open where bluebirds can see them but away from shrubbery where mockingbirds like to nest may help. There are also special feeders designed with a 1.5-inch diameter entry hole so larger birds cannot enter but the bluebirds will be able to feed freely. And, as always, squirrels enjoy a plate of free food, so a baffle or weight-sensitive addition may help keep them out of the bluebird feeder.

Water is essential to all songbirds, and a shallow birdbath—less than three inches deep—is recommended for all birdfriendly yards. Birds love clean, moving water, and arranging for the water to ripple or move also cuts down on the possibility of housing mosquito larvae in summer. A bottle suspended above the birdbath with a small hole for dripping can provide enough movement to attract birds and discourage mosquitos.

Combining habitat, food and water will greatly increase chances to attract nesting birds. And, as the last few decades have shown, providing nest boxes can help the populations of songbirds continue where habitat loss and development have squeezed them out of natural surroundings. Bluebird trails have been highly successful and continuing to place more nesting boxes will help ensure nesting success in the future.

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While it is true that bluebirds are territorial of other bluebirds, they do not seem to mind other species in nest boxes closer to their own. We found this to be true in our yard when the brown-headed nuthatches wanted to use our bluebird house. The nuthatches usually won in my yard because they seem to nest a week earlier then the bluebird. We put another bluebird house about twenty feet away from our original bluebird house and within days we had two families—the happy little nuthatches and the soughtafter bluebirds. Both nests were successful and we have had this situation repeat itself in many nesting seasons since. This is one of the best tricks to getting nesting bluebirds—put out additional houses. —Jill

Photographer Chuck Carmack visited a retention pond behind Wilmington Mayfaire Cinema, hoping to find ducks he could photograph. He was surprised to see 200–300 bluebirds. Eastern Bluebirds are very territorial during nesting season, but in winter may bunch together for protection.

Author Jill Peleuses is co-owner of Wild Bird & Garden, Inc. in Wilmington and co-founder of the Cape Fear Bird Observatory. (See www. capefearbirdobservatory.org.) She sponsors educational events on bird habits and habitat and leads birding hikes in Airlie Gardens.