Eastern Bluebird
Poets might describe this seven-inch bird as the joining of blue skies and red earth, but its scientific name Sialia sialis doesn’t provide any intrigue, even when translated. Birders and those living in open country appreciate the bright colors that bluebirds bring to Carver County summers.
Bluebirds are most often seen perched on wires and fences, often with others who are looking down for insects on the ground. They will drop down, catch a bug, then quickly resume their watch. After filling their own stomach, hunting will continue so they can bring their groceries back to their nest to feed the female and their nestlings. She may do some of the hunting, but her roles as a nest builder and caregiver keep her busy. The female’s grayish head and subdued blue wings and back still are distinctive to identify her species.
The newly fledged juveniles, however, present some identification challenges. First, they aren’t very blue – regardless of their sex. Second, their backs have white spots and their chests are gray and full of dark spots. Third, the youngsters probably aren’t doing much hunting and are usually hiding in the shade of bushes or leaves. Without sunshine reflecting from their wings, none of the bluebirds show the bright color of their name. Two months or so after hatching, juveniles will molt their spotted chest feathers and start to show the rufous breast colors of their parents.
Sixty years ago, the fate of the eastern bluebird species was not looking good. Pesticide use, loss of bug-filled meadows and nest-hole competition from starlings and house sparrows were causes for decreased numbers throughout the species’ range in eastern North America. As awareness of their plight grew, “bluebird trails” established lumber-built boxes alongside spaces of wild grasses and low shrubs. With holes sized too small for competitors, these habitats augmented the natural nesting spaces created by woodpeckers, and bluebird populations have increased.
Towards the end of August and into September, eastern bluebirds will have raised their young—sometimes they will have three broods in one season—and they’ll have berries to supplement their diet of insects. Eventually, instinct and seasonal cues will take over and southward migration will occur for those that spend the breeding season in Canada and cold northern states. Winters in southern states, Mexico and Central America will provide them with time and resources to recover from their migration journey and the stress of the breeding season. In one documented study, after a southern winter, 26 percent of banded individuals returned as adults to their hatching areas.
A late May freezing spell might result in fatal conditions, but if you’re in an area within Carver County that supports bluebird nesting, you probably will see them every year. Visits to the county’s many parks will also result in sighting these beautiful and welcomed birds of the sky and earth.
Sept. 24 is “Bluebird of Happiness Day” that celebrates these symbols of joy and happiness. Don’t forget to stop and enjoy a bluebird.
For more information:
The Sibley Guide to Birds, David Allen Sibley
Birds of Minnesota and Wisconsin, Janssen, Tessen, and Kennedy
Birds of Minnesota, Robert B. Janssen
The Audubon Society’s Encyclopedia of North American Birds, John K. Terres
Birds of the World, Cornell Lab of Ornithology
Online: All About Birds, Cornell Lab of Ornithology LINK
Online: Minnesota Breeding Bird Atlas
