The song “Zip-a-Dee-Doo-Dah” memorably wedded bluebirds with wonderful days in the 1946 Disney movie Song of the South. Wikipedia, however, opines that their role as harbingers of happiness may date back much further, perhaps thousands of years.
When the movie came out, bluebird populations were in severe decline. Among other causes, they lost habitat to humans and suffered from predation by human-introduced species, including house sparrows, starlings, and domestic cats. Much of this and more we learned from Kurt Hagemeister, president of the Michigan Bluebird Society, and Juliet Berger, Ann Arbor’s city ornithologist.
The good news is that, with human help, bluebirds have made a remarkable recovery. Knowledgeable foresters and gardeners are now more inclined to leave deadwood in places where it can provide housing and shelter for bluebirds and other wildlife. And humans have done a bang-up job of putting up bluebird housing.
Bluebird trails–strings of nest boxes placed far enough apart so as to not create intraspecies territorial conflicts–have sprung up all over bluebird country. Bluebirds can usually find food of some sort wherever they go, but housing is hard to come by. Unlike their cousin, the American robin (both are thrushes), bluebirds do not build cup nests. Instead, they rely on natural nesting cavities, such as those carved by woodpeckers–and, in recent years, human-built alternatives. Berger says she’s seen a substantial increase in the bluebird population here since the city’s Natural Area Preservation unit started putting up bluebird boxes earlier in this century.
A bluebird trail runs from Gallup Park to Parker Mill Park along the Border-to-Border Trail. NAP has also placed bluebird boxes elsewhere, including the Leslie Park and Huron Hills golf courses. Hagemeister also suggests looking for bluebirds at Matthaei Botanical Gardens and Hudson Mills Metropark, which has a really good nest box program.
Nongovernmental entities and individuals also put up bluebird boxes. Providing a nest box will not guarantee bluebirds in all environments, but if the offer is accepted, the bluebird landlord may be treated to fledglings not just once, but twice yearly. Two broods, one following quickly after the other, are common in this area.
While we typically look for bluebirds in the spring, some overwinter here. They are not as visible in the winter, though, because they range over a wider area looking for food and spend more time in the woods, sheltering in spruces and pines. Hagemeister told us that more males overwinter than females–those that do gain an advantage in staking out the best territories come spring.
When you admire a bluebird, the color you see is all in the eye of the beholder: bluebird blue is not a pigment, but a structural arrangement of feathers and their interplay with light waves, sending blue wavelengths to our eyes.
Much more about bluebirds, suitable bluebird environments, bluebird housing and feeding, and predator control can be found on the websites of the Michigan Bluebird Society (michiganbluebirds.org) and the North American Bluebird Society (nabluebirdsociety.org).
Go bluebirding!
