Eastern Bluebird - Sialia sialis
The Eastern Bluebird is a small thrush (16 to 21 cm long) with a wingspan of approximately 33 cm. The male has a bright blue back, head, wings, and tail. The throat, sides of the neck, and upper breast are orange, with the orange on the breast extending down the flanks. The white belly is bright and apparent. The female is similarly colored, but is duller overall. The head and back are more of a gray or gray-blue than blue, but the wings and tail are primarily blue. Unlike the male, the female has a white throat. On both sexes, the eye is black, and the bill is dark and stout, with a yellow gape (Gowaty and Plissner 1998, Sibley 2000).
Vocalization of the Eastern Bluebird is described as a song of mellow whistles sounding somewhat like "chiti WEEW wewidoo"
(Gowaty and Plissner 1998, Sibley 2000). The male sings loudly from high, conspicuous perches, sometimes during flight (Gowaty and Plissner 1998).
For a comprehensive review of the conservation status, habitat use, and ecology of this and other Montana bird species, please see Marks et al. 2016, Birds of Montana.
The plumage of the male Eastern Bluebird is most similar to that of the Western Bluebird. The Eastern Bluebird is discernable by its white belly, orange throat and blue scapulars, while the Western Bluebird has a blue belly and throat and chestnut scapulars. The features distinguishing the female Eastern, Western, and Mountain Bluebirds are less distinct. The Eastern Bluebird female is distinguishable from the Western Bluebird by the white throat, rufous on the sides of the neck, and more distinct rufous flanks. The Eastern Bluebird is darker overall than the Mountain Bluebird, with more rufous-orange on the flanks, upper breast, and sides of the neck. The Western Bluebird and Mountain Bluebird females lack the white throat. In addition, the bill of the Eastern Bluebird is thicker and stouter than that of the two other bluebird species.
Western Hemisphere Range
eBird Occurrence Map
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Observations in Montana Natural Heritage Program Database
Number of Observations:
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(direct evidence "B")
(indirect evidence "b")
No evidence of Breeding
(regular observations "W")
(at least one obs. "w")
(Observations spanning multiple months or years are excluded from time charts)
Based upon limited records, spring arrival occurs in May. Records indicate that birds are present through August, and fall migration begins soon after. In 1990, the presence of an individual bird was recorded at Long Pines, Carter County as late as October (Montana Bird Distribution Committee 2012).
Limited specific information exists on habitat use by Eastern Bluebirds in Montana, but the species may generally be limited to the deciduous trees (primarily cottonwood, Populus spp.), along the rivers of eastern Montana, which can provide significant habitat where nest boxes haven't supplanted these natural nesting sites (Johnsgard 1986, Gowaty and Plissner 1998).
Other frequently used habitats can include pastures, roadsides, farmlands, meadows, yards, and other open grassy areas that might provide adequate foraging habitat (Northern Prairie Research Center 2003). Reports of breeding in the state indicate the use of nesting boxes, with other potential nesting sites including old woodpecker holes and natural cavities in riparian forests, shelterbelts, farmsteads and city parks (Johnsgard 1986, Montana Bird Distribution Committee 2012).
Ecological Systems Associated with this Species
- Details on Creation and Suggested Uses and Limitations
How Associations Were Made
We associated the use and habitat quality (common or occasional) of each of the 82 ecological systems mapped in Montana for
vertebrate animal species that regularly breed, overwinter, or migrate through the state by:
- Using personal observations and reviewing literature that summarize the breeding, overwintering, or migratory habitat requirements of each species (Dobkin 1992, Hart et al. 1998, Hutto and Young 1999, Maxell 2000, Foresman 2012, Adams 2003, and Werner et al. 2004);
- Evaluating structural characteristics and distribution of each ecological system relative to the species' range and habitat requirements;
- Examining the observation records for each species in the state-wide point observation database associated with each ecological system;
- Calculating the percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system to get a measure of "observations versus availability of habitat".
Species that breed in Montana were only evaluated for breeding habitat use, species that only overwinter in Montana were only evaluated for overwintering habitat use, and species that only migrate through Montana were only evaluated for migratory habitat use.
In general, species were listed as associated with an ecological system if structural characteristics of used habitat documented in the literature were present in the ecological system or large numbers of point observations were associated with the ecological system.
However, species were not listed as associated with an ecological system if there was no support in the literature for use of structural characteristics in an ecological system, even if
point observations were associated with that system.
Common versus occasional association with an ecological system was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species as represented in scientific literature.
The percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system was also used to guide assignment of common versus occasional association.
If you have any questions or comments on species associations with ecological systems, please contact the Montana Natural Heritage Program's Senior Zoologist.
Suggested Uses and Limitations
Species associations with ecological systems should be used to generate potential lists of species that may occupy broader landscapes for the purposes of landscape-level planning.
These potential lists of species should not be used in place of documented occurrences of species (this information can be requested at: mtnhp.org/requests
) or systematic surveys for species and evaluations of habitat at a local site level by trained biologists.
Users of this information should be aware that the land cover data used to generate species associations is based on imagery from the late 1990s and early 2000s and was only intended to be used at broader landscape scales.
Land cover mapping accuracy is particularly problematic when the systems occur as small patches or where the land cover types have been altered over the past decade.
Thus, particular caution should be used when using the associations in assessments of smaller areas (e.g., evaluations of public land survey sections).
Finally, although a species may be associated with a particular ecological system within its known geographic range, portions of that ecological system may occur outside of the species' known geographic range.
- Adams, R.A. 2003. Bats of the Rocky Mountain West; natural history, ecology, and conservation. Boulder, CO: University Press of Colorado. 289 p.
- Dobkin, D. S. 1992. Neotropical migrant land birds in the Northern Rockies and Great Plains. USDA Forest Service, Northern Region. Publication No. R1-93-34. Missoula, MT.
- Foresman, K.R. 2012. Mammals of Montana. Second edition. Mountain Press Publishing, Missoula, Montana. 429 pp.
- Hart, M.M., W.A. Williams, P.C. Thornton, K.P. McLaughlin, C.M. Tobalske, B.A. Maxell, D.P. Hendricks, C.R. Peterson, and R.L. Redmond. 1998. Montana atlas of terrestrial vertebrates. Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT. 1302 p.
- Hutto, R.L. and J.S. Young. 1999. Habitat relationships of landbirds in the Northern Region, USDA Forest Service, Rocky Mountain Research Station RMRS-GTR-32. 72 p.
- Maxell, B.A. 2000. Management of Montana's amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species. Report to U.S. Forest Service Region 1. Missoula, MT: Wildlife Biology Program, University of Montana. 161 p.
- Werner, J.K., B.A. Maxell, P. Hendricks, and D. Flath. 2004. Amphibians and reptiles of Montana. Missoula, MT: Mountain Press Publishing Company. 262 p.
- Commonly Associated with these Ecological Systems
Forest and Woodland Systems
Recently Disturbed or Modified
Shrubland, Steppe and Savanna Systems
Wetland and Riparian Systems
- Occasionally Associated with these Ecological Systems
Human Land Use
No information regarding food habits exist for Eastern Bluebird in the state. Other studies outside of Montana indicate Eastern Bluebirds eat mainly insects, but will also consume other invertebrates and small fruits. Primarily a ground-forager, this bird will perch on a branch, post, or wire and swoop to catch prey items on or near the ground (Northern Prairie Research Center 2003). Orthoptera and beetles comprise a large portion of the Eastern Bluebird's diet (Terres 1980). While foraging fruit, which this species consumes primarily in late summer and into winter, the bird will land on the stalks of fruiting bushes or in trees to pluck fruit from the perch (Gowaty and Plissner 1998). Eastern Bluebirds may also be observed gleaning insects from foliage.
No Eastern Bluebird ecological information is available from Montana. Studies from other areas in the species' range state that Eastern Bluebirds are a territorial species and are known to prefer nesting boxes that are at least 100 yards from other bluebird nests (Gowaty and Plissner 1998). Nesting territories range from 1.1 to 2.0 hectares in size, and decrease as the nesting season advances, possibly in response to an increase in food availability or the need for parents to more closely protect the nestlings (Gowaty and Plissner 1998).
Ectoparasites of the Eastern Bluebird include lice (Philopterus sialii, Ricinus sp.); mites (Analgopsis sp. and Dermanyssus prognephilus) (Gowaty and Plissner 1998); flies (Ornithomyia anchineuria); eye worms (Oxyspirura pusillae) (Gowaty and Plissner 1998); nasal mites (Sternostoma siliphilus and Boydaia spatulata) (Gowaty and Plissner 1998); and trematodes (Collyriclum faba) (Kibler 1968, Gowaty and Plissner 1998). Predation by chipmunks (Tamias sp.), and Northern Flying Squirrels (Glaucomys volans) on the Eastern Bluebird is common, the former species raids the nests and eats eggs or young. Adults, nestlings, and/or young can become prey to the House Sparrow, European Starling, domestic cat (Felis domesticus), American Black Bear (Ursus americanus), Raccoon (Procyon lotor), and American Kestrel (Falco sparverius) (Gowaty and Plissner 1998).
Given the rarity of records in the state, relatively numerous nesting observations exist for Montana. The breeding records indicate that at least three eggs have been produced (when eggs have been observed) and on more than one occasion four fledglings have been noted. Four breeding accounts indicate that nesting took place in nest boxes, with breeding dates ranging from May to July (Montana Bird Distribution Committee 2012).
Other than the placement of nesting boxes in appropriate habitat, no management activities designed specifically for the Eastern Bluebird in Montana are known.
- Literature Cited AboveLegend: View Online Publication
- Gowaty, P.A. and J.H. Plissner. 1998. Eastern Bluebird (Sialia sialis). Species Account Number 381. The Birds of North America Online (A. Poole, Ed.). Ithaca, NY: Cornell Laboratory of Ornithology; Retrieved 3/25/2008 from The Birds of North America Online database
- Johnsgard, P.A. 1992. Birds of the Rocky Mountains with particular reference to national parks in the northern Rocky Mountain region. Lincoln: University of Nebraska Press. xi + 504 pp.
- Kibler, L.F. 1968. Collyriclum faba: a challenge to banders. EBBA News 31:257-262.
- Marks, J.S., P. Hendricks, and D. Casey. 2016. Birds of Montana. Arrington, VA. Buteo Books. 659 pages.
- Montana Bird Distribution Committee. 2012. P.D. Skaar's Montana bird distribution. 7th Edition. Montana Audubon, Helena, Montana. 208 pp. + foldout map.
- Northern Prairie Wildlife Research Center (n.d.) Retrieved September 10, 2003.
- Sibley, D.A. 2000. The Sibley guide to birds. National Audubon Society and Alfred A. Knopf, Inc., New York, NY. 544 pp.
- Additional ReferencesLegend: View Online Publication
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- American Ornithologists’ Union [AOU]. 1998. Check-list of North American birds, 7th edition. American Ornithologists’ Union, Washington, D.C. 829 p.
- Baicich, P.J. and C.J.O. Harrison. 2005. A guide to the nests, eggs and nestlings of North American birds. Second edition. Academic Press, New York.
- Bailey, A.M. and R.J. Niedrach. 1965. Birds of Colorado. Denver Museum of Natural History. 895 pp.
- Bird Conservancy of the Rockies. 2017. Pocket Guide to Northern Prairie Birds. Brighton, CO: Bird Conservancy of the Rockies. 98 p.
- Dobkin, D. S. 1992. Neotropical migrant landbirds in the Northern Rockies and Great Plains. U.S.D.A. For. Serv. N. Region Publ. R1-93-34. Missoula, Mont.
- Dobkin, D.S. 1994. Conservation and management of neotropical migrant landbirds in the Northern Rockies and Great Plains. Univ. Idaho Press, Moscow, Idaho. 220 pp.
- Ehrlich, P., D. Dobkin, and D. Wheye. 1988. The birder’s handbook: a field guide to the natural history of North American birds. Simon and Schuster Inc. New York. 785 pp.
- Gillihan, SW. and T. VerCauteren. 2015. Pocket Guide to Prairie Birds. Brighton, CO: Bird Conservancy of the Rockies. 91 p.
- Hutto, Richard L. 1995. "Composition of Bird Communities Following Stand-Replacement Fires in Northern Rocky Mountain (U.S.A.) Conifer Forests". Conservation Biology. 9 (5): 1041-1058.
- Johnsgard, P.A. 1979. Birds of the Great Plains: breeding species and their distribution. University of Nebraska Press, Lincoln. 539 pp.
- Lenard, S., J. Carlson, J. Ellis, C. Jones, and C. Tilly. 2003. P. D. Skaar’s Montana bird distribution, 6th edition. Montana Audubon, Helena, MT. 144 pp.
- Maxell, B.A. 2016. Northern Goshawk surveys on the Beartooth, Ashland, and Sioux Districts of the Custer-Gallatin National Forest: 2012-2014. Montana Natural Heritage Program. Helena, MT. 114pp.
- Northern Prairie Wildlife Research Center: Biological Resources - Eastern Bluebird. United States Geological Survey
- Pence, D. B. 1972. The genus Oxyspirura (Nematoda: Thoeloziidae) from birds in Louisiana. Proc. Helmitholo. Soc. Wash. 39:23-28.
- Pence, D. B. 1973. The nasal mites of birds from Louisiana: IX: Synopsis. Journal of Parasitology 59:881-892.
- Peters, H.S. 1936. A list of external parasites from birds of the eastern part of the United States. Bird-Banding 7:9-27.
- Pinkowski, B.C. 1976. First Michigan record of the trematode Colluriclum faba on an eastern bluebird. Jack-Pine Warbler 54:41.
- Roy F. Weston, Inc., Bozeman, MT., and Western Technology and Engineering, Inc., Helena, MT., 1989, Stillwater PGM Resources East Boulder Project Addendum F: Supplemental Biological Studies. Final Report. December 1989.
- Sibley, D. 2014. The Sibley guide to birds. Alfred A. Knopf, New York, NY. 598 pp.
- Skaar, P. D., D. L. Flath, and L. S. Thompson. 1985. Montana bird distribution. Montana Academy of Sciences Monograph 3(44): ii-69.
- Skaar, P.D. 1969. Birds of the Bozeman latilong: a compilation of data concerning the birds which occur between 45 and 46 N. latitude and 111 and 112 W. longitude, with current lists for Idaho, Montana, Wyoming, impinging Montana counties and Yellowstone National Park. Bozeman, MT. 132 p.
- Stewart, R.E. 1975. Breeding birds of North Dakota. Tri-College Center for Environmental Studies, Fargo, North Dakota. 295 pp.
- Terres, J.K. 1980. The Audubon Society encyclopedia of North American birds. Alfred A. Knopf, New York. 1109 pp.
- U.S. Forest Service. 1991. Forest and rangeland birds of the United States: Natural history and habitat use. U.S. Department of Agriculture, Forest Service Agricultural Handbook 688. 625 pages.
- Vold, S.T. 2018. Effects of livestock grazing management on the ecology of grassland birds and their predators in a northern mixed-grass prairie ecosystem. M.Sc. Thesis. Bozeman, MT: Montana State University. 176 p.
- Wright, P.L. 1996. Status of rare birds in Montana, with comments on known hybrids. Northwestern Naturalist 77(3):57-85.
- Additional Sources of Information Related to "Birds"