- Sialia sialis
Identification
Length 16·5–21 cm (6½-8¼ in), Wingspan 33cm (13 in)
Male
- Blue upperparts
- Orange throat, sides of neck, and chest
- White belly
- Blackish tips on tail
- Black eyes and legs
Female: similar, but drabber, with rusty colour in place of orange, and grey nape
Juvenile: has speckled breast.
Similar Species
Similar to Western Bluebird, which has a blue throat. Belly and undertail whiter, not as grey.
Distribution
Eastern Bluebirds are found east of the Rockies, southern Canada to the Gulf States and south-eastern Arizona and south to Nicaragua.
A rare vagrant in Cuba.
Taxonomy
Subspecies
This is a polytypic species, consisting of seven subspecies in two groups[1]:
Eastern Group
- S. s. sialis:
- Breeds in eastern North America, from southern Canada to north-eastern Mexico (southern Tamaulipas); winters from eastern United States to northern Mexico, rarely to Cuba
- S. s. bermudensis:
Guatemala Group
- S. s. fulva:
- S. s. nidificans:
- Mexico (south-western Tamaulipas to central Veracruz)
- S. s. guatemalae:
- Southern Mexico (Chiapas) and Guatemala
- S. s. meridionalis:
- Northern El Salvador, central and western Honduras, and north-central Nicaragua; birds from western Belize probably also this subspecies
- S. s. caribaea:
- Eastern Honduras and north-eastern Nicaragua
Habitat
Found in open stands of mature pine woods and dead trees, farmlands and orchards.
Behaviour
The bright blue breeding plumage of the male, makes it easy to see when perched on a wire or open perch, prior to fluttering down to the ground to feed.
Diet
The diet consists of insects such as grasshoppers, crickets or beetles during the summer with fruit and berries added in the autumn and winter months. Feeds mostly in open to semi-open areas.
Defends its feeding areas in winter, even when in flocks.
Breeding
Breeding season mainly from March to August with a peak in April in all areas. Most populations are double-brooded, however birds in boreal Canada and Florida are mostly single-brooded, while in the south of its range many pairs breed three times a year (with records of up to five broods in one season). A monogamous species, but polygyny and polyandry occur. Can be a semi-colonial nester if the opportunity arises.
The nest is a loose cup made of grass and/or pine needles. It's placed in cavities including bird houses. Lays 3 to 7 eggs. 13 to 14 days incubation period is followed by 18 to 19 days nestling period.
Brood parasitism by Cowbirds occurs but is low.
Movements
Northern populations migrate south in small groups, sometimes in flocks of several hundreds. A diurnal migrant.
Migrating birds arrive in their breeding grounds from late February to mid-May and leave again from late September to October or mid-November. In Central America residents move to lower altitudes in winter.
References
- Clements, J. F., T. S. Schulenberg, M. J. Iliff, S. M. Billerman, T. A. Fredericks, J. A. Gerbracht, D. Lepage, B. L. Sullivan, and C. L. Wood. 2021. The eBird/Clements checklist of Birds of the World: v2021. Downloaded from https://www.birds.cornell.edu/clementschecklist/download/
- Gowaty, P. A. and J. H. Plissner (2020). Eastern Bluebird (Sialia sialis), version 1.0. In Birds of the World (A. F. Poole, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.easblu.01
Recommended Citation
- BirdForum Opus contributors. (2024) Eastern Bluebird. In: BirdForum, the forum for wild birds and birding. Retrieved 19 April 2024 from https://www.birdforum.net/opus/Eastern_Bluebird
External Links
GSearch checked for 2020 platform.1
