Blane Klemek: Bluebirds bouncing back
I checked some of my bluebird houses recently. Not as many bluebirds seem to be occupying the houses this season as last, and I suspect the reason might be because of the oddball spring. After all, some migrants, including bluebirds, returned to the Northland at the typical time, but I believe the unending winter might have delayed courtship and nesting in some locales.
Even so, a bluebird box I have mounted on a short pole alongside Lake Assawa has four little featherless bluebird chicks inside it. And when I whistled softly at them while peering through the entrance hole, all four heads popped up with their mouths agape.
Though there are a few other species inhabiting North America that are blue in color, only the bluebird has a reddish breast. The blue jay, for instance, which is much larger, has a whitish breast and a crested head. Meanwhile, the indigo bunting and blue grosbeak have all-blue breasts. As well, the bluebird, as my field guidebook reads, has a slight “hunched posture, eye ring, and the blue in wings and tail.”
Eastern bluebirds are relatively small songbirds at about 5 to 7 inches in length. They are also cavity-nesting birds. In other words, bluebirds nest inside holes in trees that are most often the result of hard working woodpeckers. Bluebirds simply do not have the wherewithal to chisel out their own tree holes, so the birds have to rely on woodpeckers for cavity construction.
Really, this is not that unusual for birds and other animals. Burrowing owls in the Great Plains utilize the excavations of burrowing mammals like prairie dogs for their nest sites. Great horned and long-eared owls seek out abandoned crow, magpie, and hawk nests to use as their nests. For some reason, these and other owls never learned the art of nest building. Furthermore, and much to the delight of wildlife enthusiasts, bluebirds readily accept and use artificial nest boxes.
Bluebirds belong to the same family of birds as robins and thrushes. Though not commonly observed on the ground like robins and thrushes, bluebirds are most often seen perching on fence posts, utility wires or on conspicuous branches from where they watch to ambush insects.
Like all members of the family, bluebirds feed primarily on insects, but will forage on berries if insects are scarce. This frequently occurs when migrating birds arrive at their northern breeding grounds and cold weather sets in. When this happens, insects are inactive and difficult to locate. Fruit-bearing trees and shrubs that have kept their fruits throughout the winter then become a highly important food source.
Eastern bluebirds typically arrive to our region between late March and early April. Preferred habitats include orchards, meadows, farms, roadsides, golf courses, backyards, cemeteries, and open woodlands. The male, bright blue with a rusty-red upper breast and white belly, sings from favored perches throughout his territory. Female bluebirds’ plumage is somewhat less brilliant than male birds.
Soon after their arrival, breeding and nesting takes place and both parents cooperate in raising their clutch of usually four or five nestlings. After an incubation period of just 12 to 14 days, fledging takes place about 20 days later. Second clutches are frequently raised and sometimes the young of the first brood assist parents in caring for the second brood.
Not long ago, eastern bluebird populations were perilously low. Habitat loss has most affected bluebird distribution and abundance, but competition for nest sites from non-native species of birds like the house sparrow and European starling has also contributed to bluebird decline. But thanks to conservation-minded individuals, groups, and wildlife agencies such as the Minnesota Department of Natural Resources and its Nongame Wildlife Program, bluebird populations are not nearly as troubled as they once were.
All across eastern bluebird range, which includes much of the eastern United States, parts of the Great Plains to Texas, and throughout southern portions of Canada, countless numbers of ambitious projects have been implemented to assist in the bluebird recovery. Miles and miles of “bluebird trails” with houses along their routes have been established in order to increase the availability of nesting habitat and to increase bluebird populations.
Indeed, few birds have received as much attention as the eastern bluebird. Four states have adopted the bluebird as their state bird and it is the focus of many organizations, societies, and events devoted entirely to bluebird awareness and conservation.
The male’s sweet song and beautiful plumage, both sexes’ parental devotion to their young, and their ready acceptance of artificial nesting boxes, make them a favorite of everyone that appreciates these beautiful blue birds. There’s no question that catching sight of an eastern bluebird is a special and rewarding moment as we get out and enjoy the great outdoors.
— Blane Klemek is a Minnesota DNR wildlife manager. He can be reached at firstname.lastname@example.org