Eastern Bluebird
Eastern Bluebird Sialia sialis
Sound (138 KB)
DESCRIPTION:
Size:
7 inches (18 cm)
Abundance:
• Common
Quick Identification:
• Male: bright blue back, head, wings, tail
• Female: pale blue, gray head
• Chestnut-red throat and chest
Identification Tips:
• Thin bill
• Most often seen in open habitats: agricultural areas, wood edges, et al
• Southwestern United States birds are paler
Adult male:
• Bright blue upperparts
• Orange-red throat, breast and sides
• White belly and undertail coverts
Female:
• Blue wings and tail-duller than male
• Gray crown and back
• White eye ring
• Brownish throat, breast and sides
• White belly and undertail coverts
Juvenile:
• Blue wings and tail-duller than male
• Gray crown and back
• White eye ring
• Spotted underparts
Similar species:
• The Eastern Bluebird is most likely to be confused with other bluebirds. Male Western
Bluebirds have blue throats while male Easterns have orange-red ones. Male Mountain
Bluebirds lack any reddish coloration on their underparts. Females are more difficult to
separate. Both Western and Mountain Bluebirds have gray throats and gray bellies while the
Eastern Bluebird has a brownish throat and white belly.
HABITAT:
Open woodlands, clearings, farmlands, parks, orchards, gardens, fields, along roadsides on
utility wires and fences. Numbers declined due to competition from starlings and house
sparrows for nest sites. Making a comeback as people erect bluebird houses.
NESTING & FEEDING:
BREEDING: Forest edge, burned or cutover woodland, open country with scattered trees. 2,
occasionally 3 broods. Mating system is monogamous.
DISPLAYS: Courting male sings and flutters in front of female, wings half open, tail
spread, then perches beside and preens female, and may offer food.
NEST: Often in woodpecker-excavated cavity; loose cup of grass, weed stems, pine needles,
twigs, occasionally with hair or feathers. Built in average 10-11 days. Female
occasionally builds more than 1 nest.
EGGS: Pale blue, occasionally white, unmarked. 0.8" (21 mm).
CHICK DEVELOPMENT: Female incubates. Incubation takes 12-14 days. Development is altricial
(immobile, downless, eyes closed, fed). Young leave the nest after 15-20 days. Both sexes
tend young.
DIET: Including insects, fruit, earthworms, snails, other invertebrates; especially
berries. Young fed primarily insects. Hawking often from low perch, catching insects near
ground. Very dependent on berries in winter.
CONSERVATION: Winters mostly within U.S. Blue List 1972, 1978-82, Special Concern 1986.
Felling dead trees and removing dead branches reduces nest holes and increases competition
with other cavity-nesting species (especially House Sparrows and European Starlings). Nest
boxes now maintain populations that have declined by up to 90% this century. Rare cowbird
host.
NOTES: Young from previous brood occasionally help at parent's nest. Broods often derived
from more than 1 female and/or more than 1 male, indicating less than total fidelity by
both sexes, and egg dumping by some females. Often successfully defend nest hole against
swallows or House Sparrows (but not starlings), although sparrows occasionally kill
bluebird adults and nestlings. Female broods. Winter flocks to 100 + ; often roost singly
or in small groups in nest boxes.
WORLD RANGE:
Sialia sialis EASTERN BLUEBIRD. Open woods, forest edge, farms, pine savanna.
From s Saskatchewan and n Montana e across s Canada to s Quebec, New Brunswick and sw Nova
Scotia s to e New Mexico, ne,c,s,e Texas, Gulf coast and s Florida, and from se Arizona
(with an outlying population in sw Texas) s in w,c highlands, 1200-3200 m, of Mexico in ne
Sonora, w,sw Chihuahua, w Durango, e Sinaloa, e Nayarit, w Zacatecas, c,s Jalisco, Colima,
Michoacan, Guanajuato, San Luis Potosí, Hidalgo to sw Tamaulipas and extreme s Nuevo
León, s in Puebla to n Oaxaca. Sierra Madre del Sur in s Guerrero and s Oaxaca. N
Chiapas, c,s Guatemala, s Belize, El Salvador and nw Honduras to the Mosquitia and n
Nicaragua; lowland pine savanna in Honduras and Nicaragua. Winters from se Canada and c e
U.S. s through breeding range to ne Mexico and w Cuba. Variable at the northern extremes
of the range. Vagrants to n Yucatán Peninsula.
