Forestry & Wildlife
Bird enthusiasts and homeowners alike often list the Eastern Bluebird (Sialia sialis), a year-long resident of Alabama, among their favorites. The eastern bluebird is named for the vibrant blue color of males of the species. Females are also striking, if less vibrant, with a greyish-blue coloring. Both sexes have a rust-colored breast, leading early settlers in the region to refer to them as “blue robins.”
Bluebirds in Alabama
In Alabama, bluebirds produce two to three broods a year. The female usually begins laying eggs in mid-April and will generally lay one egg a day for several days. She incubates her eggs for approximately twelve days. Not long after hatching, the birds begin sprouting feathers. However, the male birds will not appear fully vibrant until they are one year old.
The bluebird hatchlings remain in the nest for about fifteen days. For several days after the baby birds leave the nest the male bluebird cares for the young, feeding them and teaching them how to gather food for themselves. While the male is busy caring for the young birds, the female is preparing the nest for the next brood.
Bluebirds prefer nesting near open areas such as cutover woodlands, old orchards, parks, yards, and roadsides. They are often referred to as secondary cavity nesters. Bluebirds nest in the hollow cavities of trees but cannot excavate the cavities themselves. It is becoming increasingly difficult for bluebirds to locate available tree cavities due to similar nesting requirements of non-native species, such as the highly aggressive House Sparrow (Passer domesticus). Because the availability of suitable nesting cavities has declined, bluebirds have come to rely on man-made homes.
Homeowners can build or purchase a bluebird house. Whether purchasing or building a bluebird house, it is important to ensure houses have moveable panels or hinged openings so they can be easily cleaned between nesting seasons. It’s best to erect the houses on a free-standing metal pole or PVC pipe. This provides protection from possible predators. The houses should be located in an open area with a few trees or on the edge of a forest or wooded lot. If there is no open area in the yard, place the box so that the opening faces east and looks out onto an open area. If homeowners plan to put up multiple boxes, be sure to space them at least 100 feet apart. Bluebirds are territorial and do not enjoy having neighbors close by. The further apart houses are placed, the better.
For those interested in building a bluebird box, building plans are available online in the Alabama Cooperative Extension publication, Bird Houses for Songbirds. It includes birdhouse measurements for several different species of songbirds. Other plan variations are also available online.
In addition to providing hours of entertainment, erecting bluebird houses can also provide an opportunity to learn about the species courtship behavior, migration habits, nesting, and seasonal plumage changes. Watching birds also helps to relieves stress and promotes mental wellbeing, so put up a bluebird house and begin enjoying the wildlife in your backyard.
For more information, contact Lynn Dickinson, regional Extension agent.