IdentificationScientific & Common Names, Subspecies Bluebirds

Scientific & Common Names, Subspecies Bluebirds

Note: I am still trying to verify and sort some of this out, so don’t consider it gospel (or anything else you find on the Internet that isn’t peer-reviewed or from an official agency!)

Audubon paintings, Other Common Names, Name in French, Name in Spanish, Scientific Name, Former Scientific Name Appearing in Literature, Described by, Alpha Code, ITIS Taxonomic Serial No., Subspecies, Distinguishing Characteristics (Male), Distinguishing Characteristics (Female), Differences between Species (Characteristics), Size, Range, Interbreeding, Recommended distance between nestboxes, Nests, Incubation, Fledging, State Bird, Postal Stamps, Classification and Notes.

Common Name

Eastern Bluebird

Mountain Bluebird

Western Bluebird

Audubon Plate
(John James Audubon, The Birds of America, 1840)
Common Blue-Bird Audubon Plate Artic Blue-Bird Audubon plate Western Bluebird Audubon Plate
Other Common Names
  • Wilson’s Bluebird
  • Blue Robin
  • Common Bluebird
  • Blue Redbreast
  • American Bluebird
  • Blew Bird
  • Bluebird


  • Florida bluebird (S.s.grata)
  • Tamaulipas bluebird (S.s.episcopus)
  • Azure bluebird (S.s.fulva)
  • Arctic Blue-bird
  • Ultramarine Blue-bird
  • California Bluebird


  • Chestnut-backed (S.mexicana bairdi)
  • Bluebird
  • San Pedro Bluebird (S.mexicana anabelae)
Name in French
merlebleu de l’est
merlebleu azuré
merlebleu de l’ouest
Name in Spanish

Azulejo garganta canela

Azulejo pálido
Azulejo garganta azul
Scientific Name
Sialia sialis
Sialia currucoides
Sialia mexicana
Former Scientific Names Appearing in Literature?

Sialia sialis sialis

Motacilla sialis (Linnaeus 1758)

Sialia arctica? (Audubon)
Erythaca Arctica?(Swains and Rich)

Sylvia mexicana occidentalis (Townsend)?

Described by

Linnaeus, 1758

Bechstein, 1798
Swainson, 1832
Taxonomic Serial No.
Subspecies (distinguished by coloration and range) – name is preceded by Genus and Species (e.g., Sialia sialis grata). For description see (NABS) Bluebird, Winter 2003, Vol.25, No.1
  1. Sialia sialis bermudensis (Verrill, 1901)
  2. Sialia sialis caribaea (Howell 1965)
  3. Sialia sialis episcopus (Oberholser) – note BNA lists Sialis sialis sialis (Linnaeus 1758 which includes episcopus)
  4. Sialia sialis fulva (Brewster 1885)
  5. Sialia sialis grata (Bangs 1898)
  6. Sialia sialis guatemalae (Ridgway 1882)
  7. Sialia sialis meridionalis (Dickey and van Rossem, considered part of guatemalae by Webster 1930)
  8. Sialia sialis nidificans (Phillips 1991)
No subspecies recognized.


  1. Sialia mexicana amabilis (Townsend)
  2. Sialia mexicana anabelae (Anthony, not on Phillips list)
  3. Sialia mexicana bairdi (Ridgway)
  4. Sialia mexicana jacoti (Phillips)
  5. Sialia mexicana mexicana (Swainson)
  6. Sialia mexicana nelsoni (Phillips)
  7. Sialia mexicana occidentalis (Townsend)
Distinguishing Characteristics (Adult Male)
Red-brown throat and white belly
Pale sky- blue breast and flanks. Lacks distinct red coloration but may show a trace of rufous on throat and breast. Straighter posture/
Bright purplish-cobalt-blue on head, chin, throat, and tail. Brown breast and a gray-blue belly.
Distinguishing Characteristics (Adult Female)
Orange-brown throat and white belly with pale brown outline
Pale sky-blue. Pale chin? Grayer back? Ashy gray belly, may have rufous wash on breast.

Tend to have a brown abdomen and gray head, throat and back. Tails and wings gray-blue color.

Differences between Species (Sibley and others) Like Western but smaller overall and slightly thicker-billed Slimmer, especially longer-winged and tailed, thinner bill with little or no yellow at base. Males and females paler blue. Stocky with rather short tail and wings, stout bill, large head. Darker underwing coverts than Eastern. Less vocal than EABL.
Size (Sibley) Length 7″, Wingspan 13″, WT 1.1 oz Length 7.25″, Wingspan 14″, WT 1 oz Length 7″, Wingspan 13.5″, WT 1 oz.
East of the Rocky Mountains, spanning from southern Canada to the Gulf states and on into Mexico and Honduras. Populations are found in Cuba, although it is not a native species there. (Terres, 1980)
Nests in the foothills and mountains of western North America, from east-central Alaska, east to southwestern Manitoba and the Dakotas, south to southern California, northern Arizona, and southern New Mexico. May winter as far south as Mexico, or as far north as British Columbia.
Throughout parts of western North America, including southeastern British Columbia, Alberta, Washington, Oregon, Idaho, California, Nevada, Utah, Colorado, New Mexico, Arizona, northern Baja California, and the central Mexican states. (Guinan, Gowaty, and Eltzroth, 2000)
Inter-breeding (rare in wild) Interbreeds with Mountain Hybridizes with both Eastern (Lane 1969, Rounds and Munro 1982, Steblay 1986) and Western (Aylesworth 1987) Considered extremely rare although overlap exists with MOBL in part of range
Other Differences Male may be more aggressive defending nest. Most migratory. Eggs are paler blue. Establish territories later than WEBL in areas where ranges overlap Least migratory. Do not prefer large open meadows. Establish territories earlier than MOBL.
Recommended distance between nestboxes
100 yards minimum
200-300 yards
100 yards. 200-300 yards may be better
Nestbox Hole Size 1.5″ round minimum 1 9/16″ round minimum 1.5″ round minimum
Nests Seldom (or just a few) feathers, nest usually of grass and pine needles May use twigs, rootlets, bark, and, sometimes, wool, hair, or feathers May use feathers and trash, hair, thin bark, leaves in nest cup
Incubation 12-18 days 13-15 days 13-14 days
Song Pleasing musical series of mellow whistles, sings frequently. Also a chatter. Series of low, burry whistles. Quieter than EABL? Male warbles at dawn, also sings in flight. Sings infrequently, mainly at dawn; simple series of call notes.
Fledging 12-19 days 17-22 days +/- 18-24 days +/- Average 21.8
State Bird
  • Missouri (1927)
  • New York (1970)
  • Idaho (1931)
  • Nevada (1967)
Postal Stamps (year issued)
  • 1982: 20 cent State Birds and Flowers series (MO, NY)
  • 1991: three cent (does not have a “¢” symbol after the number)
  • 1996: 3 cent again
  • 1982: 20 cent State Birds and Flowers series (ID, NV)
  • 1990: 25 cent for the Idaho Statehood Centenary
  • 1997: 45 cent Birds of Canada series
Has never appeared on a U.S. stamp.

Notes and References:

  • Sialia is pronounced: sy-AL-lay-uh
  • Sialia (the genus) should always be capitalized
  • “Sialia” comes from the Greek word sialis which simply means “a bird,” according to bluebirder Fred Loane.
  • Swainson described the genus Sialia in 1827.
  • Classification: Kingdom: Animalia (animals), Phylum: Chordata (chordates), Subphylum: Vertebrata (vertebrates), Class: Aves (Birds),
    • Order: Passeriformes (Perching Birds – of which there are 96 families, 1218 genera and 5753 species according to Ornithology by Frank Gill, 3rd ed.)
    • Family: per American Ornithologists Union: Turdidae (Thrushes and Allies). The ITIS lists bluebirds as being in the Family Muscicapidae (Old World Flycatchers) per the Sibley-Monroe list.
    • Subfamily: Turdinae (Thrushes) is a subfamily of Muscicapidae in the Sibley-Monroe list (second paragraph).
    • Genus: Sialia (a kind of bird), Species (3), Subspecies (14 or 15 depending on whose list you use).
  • ITIS is Integrated Taxonomic Information System, which issues Taxonomic Serial Numbers.
  • The American Ornithologists Union determines species splits or lumps, name changes and bird alpha codes in the U.S. The USGS Patuxent Wildlife Research Center also maintains a list of bird alpha codes.
  • Subspecies information from (NABS) Bluebird, Winter 2003, Vol.25, No.1
  • A.R. Phillips recognized 6 subspecies of the Western Bluebird in his 1991 paper, The Known Birds of North and Middle America, Part II
  • J.D. Webster, Middle American Races of the Eastern Bluebird, The Auk 90: 579-590.
  • Some information from USDA Forest Service
  • David Allen Sibley, The Sibley Guide to Birds, November 2001
  • Native american names for bluebirds include: Chimalis or Chimalus, Chosovi (Hopi) – source: Spotted Wolf’s Corner, Native American Names; Chimalus version from Indian Popular Names, from the Library of the University of California, L.A., E98 N2U5)
  • On this website, also see:

The bluebird is well named, for he wears a coat of the purest, richest, and most gorgeous blue on back, wings, and tail; no North American bird better deserves the name, for no other flashes before our admiring eyes so much brilliant blue.
– Arthur C. Bent, 1949


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