Eastern Bluebird

Sialia sialis

Judy Lyle
  • Thrushes

The familiar blue songbird is a year-round resident from the mid-Atlantic States south to northern Florida and west to Oklahoma and eastern Texas. In the summer it ranges farther north to southern Canada. A separate population ranges from southeastern Arizona south into Mexico. Bluebirds nest in tree cavities and eat both insects and small fruits. They can be helped by placing and maintaining bluebird nest boxes and planting fruiting trees and shrubs.

What Eastern Bluebirds Need

Food: Bluebirds feed on insects and other arthropods and also on small fruits. During spring and summer, insects and other arthropods predominate. Bluebirds survey the ground from a perch and drop down to pick up prey from the ground. In late summer through winter, a wide variety of small fruits and berries dominate the diet.
Nesting: Bluebirds are secondary cavity nesters, utilizing woodpecker holes and other natural cavities as well as bird boxes. They will nest in a wide range of open habitats. Nests are open cups 1 to 4 inches high, made of dried grass or pine needles. Eggs (usually 4 to 6) are powdered blue color.
Shelter: Bluebirds sleep in nest cavities or on sheltered branches of trees and shrubs.
Other: House Wrens, House Sparrows, and Tree Swallows are aggressive nest site competitors and may drive bluebirds from nest boxes. Raccoons, cats, fire ants, and snakes may kill nestlings.

How You Can Help

* Install and maintain a live mealworm feeder.
* Plant native fruiting trees and shrubs along field or woodland edges, including blueberry, sumac, sassafras, and pin cherry.
* Limit pesticide use on fruiting trees and shrubs and on insects in proximity to nesting bluebirds
* Whenever safe to do so, leave standing dead trees (snags) and small fence posts to provide perches for foraging bluebirds.
* Provide nest boxes 3-6 feet up on fence posts or low poles in open areas away from trees. Inside of box should be at least 4 x 4 inches wide and 8-12 inches deep, with a 1 1/2 inch entrance hole.
* Monitor nest boxes at least weekly to check for predation or other problems.
* For more details on nest box specifications and nest box management see www.nabluebirdsociety.org.
* Plant scattered native trees and shrubs near open nesting and foraging areas to provide adequate roosting opportunities.
* Provide several boxes in appropriate areas to make room for bluebirds and other cavity nesters.
* Remove House Sparrow nests from boxes.
* Install predator guards below nest boxes to keep climbing predators from reaching nests.
* Discourage cats and raccoons by providing a 5 inch roof overhang above the nest box entrance hole.

Climate change and the Eastern Bluebird

According to Audubon's scientists, many North American birds, including the Eastern Bluebird, are on the move, extending their winter ranges north and inland in response to warming winter temperatures.

Eastern Bluebirds are a conservation success story. Thanks in part to people who added bluebird nesting boxes to their landscapes, these bright blue and orange birds, considered very rare fifty years ago, are now found throughout the eastern U.S.  However, climate change has bluebirds wintering further and further north, which can leave them vulnerable to sudden cold snaps and food shortages.

For more information visit: http://stateofthebirds.audubon.org/cbid/index.php