This Eastern Bluebird FAQ provides quick answers to the most common questions about identification, behavior, nesting, and attracting these birds to your yard. For detailed behavioral insights and historical context, see our complete guide to Eastern Bluebirds.
Identification
What does an Eastern Bluebird look like?
Male Eastern Bluebirds have brilliant azure blue upperparts, rusty-red throat and breast, and clean white belly. Females display more subdued coloring with gray-blue wings and tail and buffy breast coloring, but maintain the same basic pattern. Male Eastern Bluebirds have bright blue upperparts, rusty-red throat and breast, and white belly. Females are grayer with more subdued coloring. According to the Cornell Lab of Ornithology, both sexes are about 7 inches long with a 13-inch wingspan, have relatively large heads, and a characteristic upright thrush posture.
How do I identify Eastern Bluebird song?
Eastern Bluebirds produce a soft, musical warbling typically transcribed as “chur-lee, chur-lee” or “tur-a-lee” in 2-3 second phrases. The song is softer and more plaintive than an American Robin’s louder carol. Males sing persistently from prominent perches during territory establishment at dawn through early breeding season. Listen to the Eastern Bluebird here.
Eastern Bluebird vs Western Bluebird – what’s the difference?
| Feature | Eastern Bluebird | Western Bluebird |
|---|---|---|
| Throat color | Rusty-red | Blue |
| Breast color | Rusty-red | Rusty-red |
| Range | Eastern US | Western US |
| Habitat | Open woodland edges | Oak woodlands |
| Range overlap | Minimal (Great Plains) | Minimal (Great Plains) |
Eastern Bluebirds show rusty-red throats while Western Bluebirds have blue throats, making identification straightforward where ranges overlap minimally in the Great Plains region.
Eastern Bluebird vs Mountain Bluebird – what’s the difference?
| Feature | Eastern Bluebird | Mountain Bluebird |
|---|---|---|
| Throat color | Rusty-red | Blue |
| Breast color | Rusty-red | Gray-blue |
| Elevation preference | Low to moderate | High elevation |
| Habitat | Open woodland edges | Mountain meadows |
| Body color pattern | Blue with rusty underparts | All blue/gray-blue |
Mountain Bluebirds lack any rusty coloring entirely and prefer higher elevation meadow habitats, making them easily distinguished from Eastern Bluebirds.
How can I tell male and female Eastern Bluebirds apart?
Male Eastern Bluebirds show brilliant azure blue upperparts with intense rusty-red coloring on throat and breast. Females have more subdued gray-blue wings and tail with buffy rather than rusty breast coloring. Both sexes share the same basic color pattern and white belly, but females appear noticeably duller overall.
Behavior & Biology
Do Eastern Bluebirds migrate?
Eastern Bluebirds are partial migrants, meaning some populations migrate while others remain year-round. Northern populations typically move south for winter, while southern populations remain in their breeding territories. Migration decisions depend primarily on food availability, with winter diet shifting from insects to berries, allowing some populations to overwinter in northern regions.
What do Eastern Bluebirds eat?
Eastern Bluebirds eat predominantly insects during breeding season (April-August), including beetles, grasshoppers, caterpillars, and crickets. Their diet shifts dramatically to berries in winter (November-March) from dogwood, sumac, holly, and eastern red cedar. This seasonal dietary flexibility allows partial populations to remain in northern ranges when insect availability drops.
How do Eastern Bluebirds hunt for food?
Eastern Bluebirds use perch-and-pounce hunting typical of the thrush family, watching for ground insects from fence posts, utility wires, or low tree branches before dropping directly onto prey. During breeding season, they add hover-gleaning behavior, briefly hovering to pick insects from foliage. Winter flocks of 5-20 birds concentrate at productive berry sources.
How long do Eastern Bluebirds live?
Eastern Bluebirds typically live 6-10 years in the wild, though many die in their first year. The oldest recorded Eastern Bluebird reached 10 years and 5 months according to Bird Banding Laboratory data. Survival rates improve significantly after the first year, with adult annual survival averaging 40-50%.
What is Eastern Bluebird habitat?
Eastern Bluebirds prefer open woodlands, orchards, or farmland edges with scattered trees, short grass or sparse ground cover for hunting visibility, and perching sites within 100 yards of nest cavities. They require protection from aggressive cavity competitors like House Sparrows and European Starlings. The species demonstrates strong site fidelity, often returning to successful nesting territories year after year.
Do Eastern Bluebirds mate for life?
Eastern Bluebirds form monogamous pair bonds during the breeding season, but these bonds typically last only for a single season rather than for life. Pair bonds may reform in subsequent years if both birds return to the same territory. Occasionally, helper birds from previous broods assist with feeding, demonstrating complex social structures beyond simple pair bonding.
Nesting & Reproduction
When do Eastern Bluebirds nest?
Eastern Bluebirds begin nesting in March-April across most of their range, with timing varying by latitude and local spring conditions. The breeding season extends through August, with pairs typically raising 2-3 broods per year. Southern populations may begin as early as February, while northern populations start in late April or early May.
How many eggs do Eastern Bluebirds lay?
Eastern Bluebirds typically lay 4-5 eggs per clutch, with clutch size varying slightly by latitude and food availability. First clutches of the season tend to be slightly larger than later broods. Eggs are pale blue to white, occasionally with faint brown spotting, and measure approximately 0.8 x 0.6 inches.
How long do Eastern Bluebird eggs take to hatch?
Eastern Bluebird eggs incubate for 13-16 days, with 14 days being most typical. The female performs all incubation while the male brings food. Eggs typically hatch synchronously within a 24-hour period, meaning all eggs in a clutch hatch at approximately the same time.
When do Eastern Bluebird chicks leave the nest?
Eastern Bluebird chicks fledge (leave the nest) at 16-21 days old, with 18-19 days being most common. After fledging, parents continue feeding young birds for 3-4 weeks while they learn to hunt independently. Fledglings from early broods occasionally help parents feed later broods in the same season.
What size hole for an Eastern Bluebird nest box?
The entrance hole should be 1.5 inches in diameter (1-9/16 inches is also acceptable). Larger holes allow House Sparrows and European Starlings to enter and compete for the box, while smaller holes may exclude bluebirds. The hole should be positioned 5-6 inches above the box floor for optimal predator protection.
Where should I place an Eastern Bluebird nest box?
Mount nest boxes 4-6 feet high on posts in open areas with short grass, facing away from prevailing winds and afternoon sun. Space boxes 100-300 yards apart in “bluebird trails” configuration. Position boxes within 100 yards of perching sites but away from dense vegetation that provides cover for predators and competitor species.
How many broods do Eastern Bluebirds raise per year?
Eastern Bluebirds typically raise 2-3 broods per breeding season, with northern populations more commonly raising 2 broods and southern populations often managing 3. Later broods may have slightly smaller clutch sizes and lower success rates. The ability to raise multiple broods helped the species recover from population lows in the 1960s-70s.
Conservation & Population
Are Eastern Bluebirds endangered?
Eastern Bluebirds are not endangered and are currently listed as a species of low conservation concern. Partners in Flight assigns them a Continental Concern Score of 8/20 (lower scores indicate lower concern). The species has increased approximately 2% annually since 1966 according to Breeding Bird Survey data, representing one of conservation’s most successful grassroots recovery stories.
What caused the Eastern Bluebird population decline?
Eastern Bluebird populations declined severely from 1900-1970 due to three compounding factors: invasive cavity competitors (House Sparrows and European Starlings), pesticide impacts (particularly DDT from 1945-1972), and habitat changes from modern forest management removing natural nest cavities. By the early 1970s, populations had reached historic lows across their entire range.
How did nest boxes save the Eastern Bluebird?
Volunteer nest box programs beginning in the 1970s addressed the specific limiting factor of cavity availability. Lawrence Zeleny pioneered systematic nest box programs, which spread as “bluebird trails”—linear arrangements of boxes spaced 100-300 yards apart in open habitat. The North American Bluebird Society, founded in 1978, coordinated volunteer networks that installed tens of thousands of boxes and monitored their success.
What are the current threats to Eastern Bluebirds?
Current threats include climate change affecting insect emergence timing (creating phenological mismatches with chick-rearing periods), suburban sprawl reducing open habitat, and ongoing competition from House Sparrows at nest boxes. House Sparrows remain a persistent threat because they aggressively displace bluebirds and occasionally kill adult birds or destroy eggs. Winter berry source availability also affects survival rates in northern populations.
Attracting Eastern Bluebirds
How do I attract Eastern Bluebirds to my yard?
- Install proper nest boxes with 1.5-inch entrance holes, mounted 4-6 feet high in open areas with short grass
- Maintain short grass through mowing or grazing to provide visible hunting areas for ground insects
- Plant berry-producing shrubs including dogwood, sumac, holly, and eastern red cedar for winter food sources
- Provide perching sites such as fence posts, utility wires, or dead branches within 100 yards of nest boxes
- Avoid pesticides to maintain healthy insect populations during breeding season
Do Eastern Bluebirds come to bird feeders?
Eastern Bluebirds rarely visit traditional seed feeders but will come to specialized bluebird feeders offering live or dried mealworms. They may also visit suet feeders, particularly in winter when insect availability drops. Platform feeders offering mealworms positioned near nest boxes or perching sites have the highest success rate for attracting bluebirds.
What is a bluebird trail?
A bluebird trail is a linear arrangement of nest boxes spaced 100-300 yards apart along fence lines, field edges, or other open habitat corridors. Trails allow volunteers to efficiently monitor multiple boxes and provide enough spacing to prevent territorial conflicts between nesting pairs. The bluebird trail concept, pioneered in the 1970s, enabled the widespread nest box movement that rescued the species from population decline.
How do I keep House Sparrows out of bluebird nest boxes?
Monitor boxes weekly during breeding season and remove House Sparrow nesting material immediately (they build messy nests with grass, feathers, and debris). Consider installing sparrow spookers or monofilament line deterrents after bluebirds begin nesting. Position boxes away from buildings and barns where House Sparrows concentrate. Some monitors use traps specifically designed for House Sparrows to protect active bluebird nests.
Can Eastern Bluebirds and Tree Swallows share nest boxes?
Not as roommates, but as neighbors. Eastern Bluebirds and Tree Swallows can coexist on bluebird trails if boxes are placed in pairs 15-25 feet apart, allowing each species to claim a box without territorial conflict. Tree Swallows help deter House Sparrows through their aggressive defense of nest sites. This pairing strategy increases overall native cavity-nester success while maintaining both species’ breeding territories. See our complete article for more on multi-species management strategies.
For complete Eastern Bluebird identification, behavior, ecology, and historical perspective—including John Burroughs’s 1871 observations and the 150-year conservation timeline—see our full article.
Last updated: January 2026 | Data sources: Cornell Lab of Ornithology, North American Breeding Bird Survey, Partners in Flight, North American Bluebird Society