Eastern Bluebird

Common Name:
Eastern Bluebird
Scientific Name:
Sialia sialis
Type:
Birds
Size:
Length: 7 inches
IUCN Red List Status:
Least concern
Current Population Trend:
Increasing

The eastern bluebird is a species familiar to millions in eastern North America. Polytypic. Length 7" (17.5 cm).

Identification

Male: bright blue above, with orange throat, ear surround, chest, sides, and flanks. Female: differs in that upperparts are less blue (often grayish); has partial whitish eye ring, and whitish throat bordered by brown lateral throat stripes. Juvenile: very similar to western bluebird, but with tertials fringed cinnamon; immatures discernable with duller upperparts and browner primary coverts. Flight as in other bluebirds; pale wing stripe less obvious than in the western bluebird.

Geographic Variation

Four subspecies in North America; compared with widespread and somewhat migratory, short-billed nominate sialis, resident fulva of southern Arizona slightly larger and paler, males with cinnamon-fringed scapulars; southern Texas nidificans larger, more richly colored, with upperparts feathers edged with cinnamon; and southern Florida grata with longer bill.

Similar Species

Male western bluebird with all-blue head, including chin and throat, and generally a deeper blue. Male western also has at least some rufous on upperparts, particularly on scapulars.

Voice

Call: musical, typically 2-noted too-lee. This call is also given in flight. Song: mellow series of warbled phrases; varied.

Status and Distribution

Common in the eastern three-fifths of the lower 48 states and in southern Canada; uncommon and local in southeastern Arizona. Breeding: nests in open woodland, second-growth habitats, and along the edges of fields and pastures, placing nest in cavity; readily accepts nest boxes. Migration: short- to medium-distance migrant. Spring: arrivals. Great Lakes ±25 February; southern Saskatchewan ±1 April. Departs northernmost range during October. Usually migrates in flocks. Winter: almost always in flocks, often mixed with yellow-rumped, pine, and palm warblers and/or dark-eyed juncos; mainly central and southern United States., but to south-central Colorado, central New Mexico, and northeastern Mexico. Vagrant: casual west to Alberta and Utah; recent local colonization in western Colorado.

Population

Nest boxes have apparently helped reverse a decline.

—From the National Geographic book Complete Birds of North America, 2006

Read This Next

See what a year looks like in the fastest-warming place on Earth
This bird survived Maui’s fires—but it could soon vanish
This bird can predict the intensity of a hurricane season

Go Further

Subscriber Exclusive Content

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet