Sustaining the once-dwindling bluebird population depends on human help.
They may just be the ultimate recyclers. Instead of building their own homes from scratch, Eastern bluebirds simply take up residence in tree and fencepost cavities left behind by woodpeckers.
There’s just one problem. “As we expanded the urban population, widened out and started cleaning up the woods and other properties, we removed all of their habitat,” says Bill Hartman, co-president of the Loudon-based Valley Chapter of the Tennessee Bluebird Society, which covers East Tennessee.
“And then we abandoned wooden fenceposts for metal fenceposts, which are a lot more durable and longer-lasting. But [the wooden ones] had holes and knots in them where bluebirds could make nests.”
By the 1970s, avian experts were so concerned about the declining numbers that they feared the birds might go extinct. In response, the North American Bluebird Society and its affiliates (there’s one in just about every Blue Ridge state) and other conservation groups started setting up nest boxes and educating the public about the importance of providing suitable spaces for the birds to raise their young. Volunteers from Tennessee’s Valley chapter alone monitor about 350 bluebird boxes during nesting season, typically from April to August.
Thanks to such efforts, it’s become much more common to spot these beautiful creatures with their blue heads and backs, peach-colored chests and white bellies. In the southernmost Blue Ridge states, where bluebirds remain in winter, they can produce up to four broods with about five eggs each year.
“The dad convinces Mom a box is a great place to live and, once he’s done that, then she builds the nest and he goes off and defends the territory from other bluebirds,” Hartman says, noting that they take turns feeding the babies until they fledge. Dad then takes over the task of teaching them how to fend for themselves while Mom starts building the nest for the next brood.
Erecting a bluebird box is an easy way to participate in the ongoing conservation initiative, says Hartman. Be careful, though, if you regularly spray your yard with pesticides, as the birds will end up ingesting the poison when they eat the insects. In fact, Hartman points out, it’s a good idea to talk to a local gardening professional about adding indigenous plants that not only support the native bug population but “the butterflies and the bees and the other birds, for that matter, because they’re all dependent on one another for survival.”
Do’s and Don’ts of Bluebird Boxes
For detailed instructions on building a bluebird nest box, see tnbluebirdsociety.org/nestbox-plans. Here are some other things you need to know to attract these colorful birds:
• Habitat. Post bluebird houses not too close together in meadows, large grassy lawns or other open areas.
• Height. Mount the box about five feet off the ground—out of reach of ground predators but low enough that the average person can access it. Use a metal pole, not a wooden one, to deter raccoons, snakes and other critters that climb.
• Design. Make sure the entrance hole is about one-and-a-half-inches in diameter; anything larger makes it easy for predatory birds to invade the nest. And, says Bill Hartman, co-president of the Valley Chapter of the Tennessee Bluebird Society, “You do not want to put a perch in front of a bluebird box because it’s just an invitation for other, larger birds to stand on the perch and stick their head in to see what they can find.”
• Ventilation. Cut a half-inch slit in each side for circulation. “In the South, when it’s 85 degrees and sunny outside,” Hartman says, “it could be 100 degrees or more inside that bluebird box.”
• Food and water. Provide a source of fresh water such as a birdbath, and clean it regularly. Bluebirds love bagworms, grasshoppers and other insects, so it’s not critical to set out food for them. But if you want to enjoy watching them up close, consider a feeder with dried mealworms or suet.
Source: Bill Hartman, co-president, Valley Chapter, Tennessee Bluebird Society
The story above first appeared in our May / June 2022 issue. For more like it subscribe today or log in with your active BRC+ Membership. Thank you for your support!