American Crow - Corvus brachyrhynchos
FWP Conservation Tier
Similar in appearance to the Northwestern Crow, this species is larger, has a higher-pitched voice, and is less social during the breeding season. Medium sized 43-53 cm, 316-575 g. All black. Adults (greater than 15 months) with feathers glossed violet; stout, glossy black bill; nares covered with stiff bristle-like feathers; and brown iris. Tips of folded wings do not reach tip of tail at rest. Tail slightly rounded. Sexes alike except male slightly larger than female. (Verbeek and Caffrey 2002).
Summary of Observations Submitted for Montana
Number of Observations:
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Map Help and Descriptions
(direct evidence "B")
(indirect evidence "b")
No evidence of Breeding
(regular observations "W")
(at least one obs. "w")
(Records associated with a range of dates are excluded from time charts)
In the Bozeman area, normal migration periods are March 10 to April 5 and September 15 to October 15.
One of the most widespread of North American birds. Found in a wide variety of habitats, particularly in open landscapes, with scattered trees and small woodlots. Uses both natural habitats and those created by humans (logged, areas, agricultural fields, cities, and villages). Generally avoids large areas of forest (Verbeek and Caffrey 2002).
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 (high, medium, or low) 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 2001, 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 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 associated as using 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 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.
High, medium, and low habitat quality was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species in the 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 assignments of habitat quality.
If you have any questions or comments on species associations with ecological systems, please contact Bryce Maxell at email@example.com
or (406) 444-3655.
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: http://mtnhp.org/requests/default.asp
) 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. 2001. The wild mammals of Montana. Special Publication No. 12. Lawrence, KS: The American Society of Mammalogists. 278 p.
- 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
Open Water / Wetland and Riparian Systems
Shrubland, Steppe and Savanna Systems
- Occasionally Associated with these Ecological Systems
Forest and Woodland Systems
Sparse and Barren Systems
Omnivorous. Wide variety of invertebrates (terrestrial and intertidal marine): amphibians; reptiles; small birds and mammals; birds' eggs; nestlings and fledglings; grain crops; seeds and fruits; carrion; and discarded human food (Verbeek and Caffrey 2002).
Nests are usually well hidden in crotches and on horizontal limbs of trees and shrubs, usually near the trunk, and more likely in upper one-third to one-quarter than at lower levels. Eggs are subelliptical to oval, usually ground color - pale bluish green or olive green, marked with irregular shaped blotches. Clutch size ranges from 3 to 6 or 7 (Verbeek and Caffrey 2002). Near Fortine, the earliest eggs were on May 5, the earliest hatch on May 10, and the earliest young on the wing was June 5. Statewide, egg dates are from the last week in April to June 26.
- Additional ReferencesLegend: View WorldCat Record View Online Publication
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- American Ornithologists' Union. 1998. Check-list of North American birds. 7th edition. American Ornithologists' Union, Washington, D.C. 829 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.
- Elliott, Joe C. and Hydrometrics, Inc., Helena, MT., 1994, Supplement to wildlife baseline investigation life-of-mine expansion plan: Regal Mine, Barretts Minerals, Inc., Madison County, Montana. August 2000. In Life-of Mine Expansion Plan: Barretts Minerals, Inc., Regal Mine, Madison County, Montana. Vol. 2. App. C: Baseline Wildlife Reconnaissance. December 1999.
- Godfrey, W. Earl. 1966. The birds of Canada. National Museums of Canada. Ottawa. 428 pp.
- Graham, Dean, and Craig Swick., 1977, A Field evaluation of the cyclone seeder for reducing Richardson ground squirrel populations causing damage in central Montana . August 1977.
- Jellison, W. L. 1933. Faunae of nests of the magpie and crow in western Montana. Can. Entomol. 65:26-31.
- Johnsgard, P. A. 1986. Birds of the Rocky Mountains with particular reference to national parks in the Northern Rocky Mountain region. Colorado Associated University Press, Boulder. xi + 504 pp.
- Land & Water Consulting, Inc., Missoula, MT., 2002, Montana Dept. of Transportation Wetland Mitigation Monitoring Report, Year 2002: Camp Creek, Sula, Montana. Proj. No. 130091.039. February 2003. In 2002 Wetland Mitigation Monitoring Reports, Vol. I.
- Land & Water Consulting, Inc., Missoula, MT., 2002, Montana Dept. of Transportation Wetland Mitigation Monitoring Report, Year 2002: Hoskins Landing, Dixon, Montana. Proj. No. 130091.038. February 2003. In 2002 Wetland Mitigation Monitoring Reports, Vol. I.
- Land & Water Consulting, Inc., Missoula, MT., 2002, Montana Dept. of Transportation Wetland Mitigation Monitoring Report, Year 2002: Peterson Ranch, Hall, Montana. Proj. No. 130091.010. February 2003. In 2002 Wetland Mitigation Monitoring Reports, Vol. II.
- 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.
- Lockhart, J. Michael, 1976, Effects of coal extraction and related development on wildlife populations. Annual progress report; Calendar year 1976. In Decker Coal Company West Pit Permit. Vol. 3. 26.4.304(10-11), 305, 306, and 307. Updated Rules Rewrite, July 1, 1991. Appendix F.
- Madge, S. and H. Burn. 1994. Crows and Jays: A guide to crows, jays, and magpies of the world. Houghton Mifflin Company, N.Y. 191 pp.
- Salt, W.R. and J.R. Salt. 1976. The birds of Alberta. Hurtig Publishers, Edmonton, Alberta. xv + 498 pp.
- Stewart, R.E. 1975. Breeding birds of North Dakota. Tri-College Center for Environmental Studies, Fargo, North Dakota. 295 pp.
- The Anaconda Co., 1976, Wildlife survey: The Anaconda Company Berkeley Complex 1976 Proposed Permit Area. May 6, 1976.
- 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.
- Verbeek, N. A., and C. Caffrey. 2002. American Crow (Corvus brachyrhynchos). Species Account Number 647. 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: http://bna.birds.cornell.edu/bna/
- Waage, Bruce C., compiler., 1984, Western Energy Company Rosebud Mine, Rosebud County, Montana: Annual Wildlife Monitoring Report, 1983 Field Season. June 1984.
- Western Energy Co., Colstrip, MT. Unpub., 1983, Western Energy Company's Application for Amendment to Surface Mining Permit NO. 8003, Area B: sections 7, 8, 17,18 T1N R41E, sections 12, 13 T1N R40E, Mining Expansion. March 1983.
- Western Energy Co., Colstrip, MT., 1982, Western Energy Company Rosebud Mine, Colstrip, Montana: Annual Wildlife Report, 1982.
- Western Technology & Engineering, Inc. (WESTECH)., 1991, 1991 Bull Mountains Mine No. 1 Terrestrial Wildlife Monitoring Study. In Meridian Minerals Company Bull Mountains Mine No. 1 Permit Application, Musselshell County, Montana. Vol. 7 of 14: Section 26.4.304(10): Text. Appendix 304(10)-8. January 31, 1990.
- Western Technology and Engineering, Inc. (WESTECH). 1994. Wildlife Monitoring Absaloka Mine Area Annual Report, 1993. Montana SMP 85005. OSMP Montana 0007C. Mar. 12, 1994.
- Additional Sources of Information Related to "Birds"