Bald Eagle - Haliaeetus leucocephalus
State Rank Reason (see State Rank above)
Populations numbers have steadily increased since the 1980s and breeding pairs now occupy a high percentage of suitable habitat across the state. However the species is still protected under the Bald and Golden Eagle Protection Act of 1940.
- Details on Status Ranking and Review
ScoreD - 1,000-2,500 individuals
CommentThe FWP Bald Eagle database documented 550 breeding territories in 2010 which indicates a minimum breeding population size of 1,100 individuals which seems to solidly place them in the 1,000 to 2,500 category.
ScoreG - 200,000-2,500,000 km squared (about 80,000-1,000,000 square miles)
Comment380,531 square kilometers based on Natural Heritage Program range maps that appear on the Montana Field Guide.
Area of Occupancy
ScoreU - Unknown
ScoreE - Relatively Stable (±25% change)
CommentPopulations declined after European arrival and then dramatically after the introduction of DDT. However, populations have rebounded and are probably best recognized as stable within +/- 25% since European arrival at this point.
ScoreF - Increasing. Increase of >10% in population, range, area occupied, and/or number or condition of occurrences
CommentThe FWP Bald Eagle database documented 280 breeding territories in 2000 and 550 breeding territories in 2010, an increase of 96% over the last 10 years. Similarly, raptor survey routes for Montana between 2000 and 2010 have also shown an increase of 60% over the past 10 years. BBS data for Montana is of lowest credibility and shows an increase of +12.5% per year or 325% increase for the last decade. BBS data for the Northern Rockies is of lowest credibility and shows an increase of +7.2% per year or 200% increase for the last decade.
ScoreF - Widespread, low-severity threat. Threat is of low severity but affects (or would affect) most or a significant portion of the population or area.
CommentEncroachment of human development on nest sites, contaminants, collisions with vehicles at road kill sites, and electrocutions all represent threats to populations in Montana.
SeverityLow - Low but nontrivial reduction of species population or reversible degradation or reduction of habitat in area affected, with recovery expected in 10-50 years.
CommentSpecies seems to be doing well and has shown the ability to recover.
ScopeModerate - 20-60% of total population or area affected
CommentProbably 20-60% of the population is being impacted by threats at any given time.
ImmediacyModerate - Threat is likely to be operational within 2-5 years.
ScoreB - Moderately Vulnerable. Species exhibits moderate age of maturity, frequency of reproduction, and/or fecundity such that populations generally tend to recover from decreases in abundance over a period of several years (on the order of 5-20 years or 2-5 generations); or species has moderate dispersal capability such that extirpated populations generally become reestablished through natural recolonization (unaided by humans).
ScoreB - Narrow. Specialist. Specific habitat(s) or other abiotic and/or biotic factors (see above) are used or required by the Element, but these key requirements are common and within the generalized range of the species within the area of interest.
CommentNarrow Specialist. Need suitable nest sites near riparian foraging areas.
Raw Conservation Status Score
3.5 – 0.25 (population size) + 0.0 (geographic distribution) + 0.25 (short-term trend) + 0.0 (threats) = 3.5
How Scores are Calculated
With a white head and tail contrasting with a dark brown body and wings, the adult plumage of the Bald Eagle, attained at approximately 5 years of age, is unmistakable. In addition to the obvious white head and tail, other distinguishing features include the yellow bill, cere, iris, legs and feet. Second in size of North American birds of prey only to the California Condor (Gymnogyps californianus
), the Bald Eagle ranges in total length from 71 to 96 cm, with an average wingspan of 168 to 244 cm and a body mass ranging from 3.0 to 6.3 kg (Buehler 2000). In general appearance the sexes are similar with females approximately 25 percent larger than males. The plumage of the juvenile birds is much less distinct, being dark brown overall. The head, body, wings, and tail are dark brown with limited mottling on the underside of the wings and on the belly. While the legs and feet of the young bird are yellow like those of adults, the bill and cere are dark gray and the iris is dark brown.
The voice of the Bald Eagle is a weak series of chirps. The vocalization is described as flat chirping, stuttering whistles, given in a halting fashion, with the immature calls generally harsher and more shrill than those of the adults (Buehler 2000, Sibley 2000).
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.
In adult plumage, the Bald Eagle is unlikely to be confused with any other species. Juvenile Bald Eagles may be confused with Golden Eagles (Aquila chrysaetos), especially with adult Goldens. A few characteristics differentiate these two species. The Bald Eagle has unfeathered legs, while those of the Golden Eagle are feathered. During flight, the head and neck of the Bald Eagle extend to about half the length of the tail, while the Golden Eagle is considerably less. This distinction is true for all age classes of both species. The terminal tail band on the Golden Eagle is dark and well defined, especially on the juveniles. In addition, the underwing and belly of the Bald Eagle show a greater amount of white compared to the Golden Eagle, whose white feathering is restricted to the base of the flight feathers (Buehler 2000).
Western Hemisphere Range
Summary of Observations Submitted for Montana
Number of Observations: 17711
(Click on the following maps and charts to see full sized version)
Map Help and Descriptions
(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)
The Bald Eagle is a resident species in the forested, mountainous areas of the state. Other individuals from more northerly latitudes either winter in Montana or migrate through the state to more southerly locations. Residents generally remain in the vicinity of their breeding areas throughout the year, while some, though remaining in the state, may move to the more temperate weather of lower elevations or to other areas with higher concentrations of food (Montana Bald Eagle Working Group 1994). This is especially true of individuals that nest at higher elevations.
Congregations of migrating Bald Eagles may be evident in autumn along the north-south mountain chains with an associated abundance of food sources; numerous eagles have been observed migrating over Rogers Pass and the Bridger Mountains (Hawk Watch International 2003). Large concentrations of eagles have formerly been reported feeding on spawning kokanee (Oncorhynchus nerka) in Glacier National Park and at Canyon Ferry Reservoir, north of Helena, when spawning fish were abundant (Montana Bald Eagle Working Group 1994). In the Bozeman area, birds arrive by November 20 and leave by April 25 (Skaar 1969).
In Montana, as elsewhere, the Bald Eagle is primarily a species of riparian and lacustrine habitats (forested areas along rivers and lakes), especially during the breeding season. Important year-round habitat includes wetlands, major water bodies, spring spawning streams, ungulate winter ranges and open water areas (Bureau of Land Management 1986). Wintering habitat may include upland sites. Nesting sites are generally located within larger forested areas near large lakes and rivers where nests are usually built in the tallest, oldest, large diameter trees. Nesting site selection is dependent upon maximum local food availability and minimum disturbance from human activity (Montana Bald Eagle Working Group 1994). See the Montana Bald Eagle Management Plan (1994) for further details including home range sizes and habitat requirements of fledgling birds.
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: 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. 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
Wetland and Riparian Systems
- Occasionally Associated with these Ecological Systems
Forest and Woodland Systems
Human Land Use
Wetland and Riparian Systems
The majority of their diet is comprised of fish. Important prey for Bald Eagles are waterfowl, especially in the winter, salmonids, suckers, whitefish, carrion and small mammals and birds (Bureau of Land Management 1986).
The number of birds in January increased from about 260 in 1980 to about 450 in 1984 (Bureau of Land Management 1986). Eagles on McDonald Creek in Glacier National Park increased from a peak of less than 50 in 1939 to a peak of more than 500 (Shea 1973), and have since declined because of a drop in the number of kokanee salmon spawning on McDonald Creek. Fall/winter concentrations have been noted on the Missouri River at Canyon Ferry Dam and at Fort Peck.
The Bald Eagle breeds at approximately 5 to 6 years of age. Nests are often massive structures of branches and sticks with an interior cup lined with grass, pine needles, and plant stems (Baicich and Harrison 1997). Nests may be used year after year, resulting in huge constructions, sometimes up to 12 feet in height and 8 feet in diameter. Most nests are in timber stands, 1.2 hectares with a canopy closure less than 80%. The most common nest trees are ponderosa pine, Douglas fir and cottonwood. The eggs are white, non-glossy, short ovals averaging 71 x 54 mm in size (Baicich and Harrison 1997). The clutch, usually consists of two eggs, but may range from one to three, and is laid in March or April. Incubation, performed by both sexes, lasts about 5 weeks. Mortality for the second young to hatch is high. First flight occurs at 10 to 12.5 weeks. The young are cared for by the adults at this time and may remain around the nest for several weeks after fledging. Adults may not reproduce every year.
Breeding dates in Montana range from March to July (Montana Bird Distribution Committee 2012). Across the state between 1980 and 2014 average nest success per year was consistently between 75 and 80%, with an average of 1.3 to 1.5 young fledged per nesting pair (DuBois 2016).
General objectives of habitat management for Bald Eagles in Montana include: maintaining prey bases; maintaining forest stands currently used or suitable for nesting, roosting, and foraging; planning for future potential nesting, roosting, and foraging habitat; and minimizing disturbances from human activities in nest territories, at communal roosts, and at important feeding sites (MBEWG 1991). The Montana Bald Eagle Management Plan (MBEWG 1994) directs management of this species in the state. Specific objectives identified in the plan include: a minimum of 800 nesting pairs in the 7-state Recovery Area; nesting success rate of 65% in occupied sites over a 5-year period with annual average production of 1.0 fledged young per pair; population goals recognized in at least 80% of management zones with nesting potential; and continued population increases for 5 consecutive years. See the Habitat Management Guide for Bald Eagles in Northwestern Montana (MBEWG 1991) and the Montana Bald Eagle Management Plan (MBEWG 1994) for further details on management guidelines and recovery objectives.
- Literature Cited AboveLegend: View Online Publication
- Dubois, K. 2016. Bald eagle nesting populations and nest monitoring, 1980-2014. FinalReport. Montana Fish, Wildlife & Parks. 27 pp.
- Marks, J.S., P. Hendricks, and D. Casey. 2016. Birds of Montana. Arrington, VA. Buteo Books. 659 pages.
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?
- Albers, Mark., 1995, Draft Biological Assessment: Tongue River Basin Project. May 1995. In Tongue River Basin Project Draft Environmental Impact Statement. Appendix B. June 1995.
- American Ornithologists Union. 1983. Checklist of North American birds, 6th Edition. 877 PP.
- American Ornithologists’ Union [AOU]. 1998. Check-list of North American birds, 7th edition. American Ornithologists’ Union, Washington, D.C. 829 p.
- Andrew, J.M. and J.A. Mosher. 1982. Bald eagle nest site selection and nesting habitat in Maryland. J. Wildlife Management 46:382-390.
- Anthony, R. G., and F. B. Isaacs. 1989. Characteristics of bald eagle nest sites in Oregon. J. Wildl. Manage. 53:148-159.
- Anthony, R. G., R. L. Knight, G. T. Allen,. B. R. McClelland and J. I. Hodges. 1982. Habitat use by nesting and roosting bald eagles in the Pacific Northwest. Trans. N. Am. Wildl. And Natur. Resour. Conf. 47:332-342.
- 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.
- Becker, D. M., and P. D. Mullen. 1985. The effects of water level fluctuations on breeding bald eagles and ospreys in the lower Flathead River Drainage, Montana Bureau of Indian Affairs, Pablo. 39 pp.
- Becker, Dale M., 1980, A Survey of raptors on national forest land in Carter County, Montana. Final Progress Report: 1977-1979.
- Bender, M. (ed.). 1994. Regional News - Region 2. End. Sp. Tech. Bull. 19(5): 18.
- Bennetts, R. E. 1986. Age-related differences in spatial distribution and behavior of bald eagles during the autumn concentration at Glacier National Park, Montana. B.A. thesis. University of Montana, Missoula.
- Bennetts, R. E., and B. R. McClelland. 1991. Differences in the distribution of adult and immature Bald Eagles at an autumn concentration in Montana. Northwest Science 65(5): 223-230.
- Bird, D. M., editor. 1983. Biology and management of bald eagles and ospreys. MacDonald. 325 pp.
- Bowerman, W. W., T. G. Grubb, J. P. Giesy, A. J. Bath, and G. A. Dawson. 1993. Population composition and perching habitat of wintering Bald Eagles in northcentral Michigan. Canadian Field Naturalist 107: 273- 278.
- Brown, B. T. 1993. Winter foraging ecology of bald eagles in Arizona. Condor 95:132-138.
- Brown, B. T., P. L. Warren, and L. S. Anderson. 1988. Status of bald eagles in the Rio Yaqui drainage of Sonora, Mexico. Page 321 in Glinski et al., eds. Proc. Southwest raptor management symposium and workshop. Nat. Wildl. Fed. Sci. and Tech. Ser. No. 11.
- Buehler, D. A. 2000. Bald Eagle (Haliaeetus leucocephalus). In The birds of North America, No. 506 (A. Poole and F. Gill, Eds.). Academy of Natural Sciences of Philadelphia and American Ornithologists’ Union.
- Buehler, D. A., et al. 1991. Differences in distribution of breeding, nonbreeding, and migrant bald eagles on the northern Chesapeake Bay. Condor 93:399-408.
- Buehler, D. A., et al. 1991. Survival rates and population dynamics of bald eagles on Chesapeake Bay. J. Wildlife Management 55:608-613.
- Buehler, D. A., et al. 1991. Winter microclimate of bald eagle roosts on the northern Chesapeake Bay. Auk 108:612-618.
- Buehler, D. A., S. K. Chandler, T. J. Mersmann, J. D. Fraser, and J. K. D. Seegar. 1992. Nonbreeding Bald Eagle perch habitat on the northern Chesapeake Bay. Wilson Bulletin 104:540-545.
- Buehler, D.A. 2000. Bald Eagle (Haliaeetus leucocephalus). In The Birds of North America, No. 506. (A. Poole and F. Gills, eds.). The Birds of North America, Inc. Philadelphia, PA.
- Buehler, D.A., T.J. Mersmann, J.D. Fraser, and J.D. Seegar. 1990. Nonbreeding bald eagle communal and solitary roosting behavior and roost habitat on the northern Chesapeake Bay. Journal of Wildlife Management 55 (2) :273-281.
- Buehler, D.A., T.J. Mersmann, J.D. Fraser, and J.K.D. Seegar. 1991. Effects of human activity on bald eagle distribution on the northern Chesapeake Bay. Journal of Wildlife Management 55 (2) :282-290.
- Bureau of Land Management. 1986. Montana Bald Eagle Management Plan. U.S.D.I., Billings, MT. 61 p.
- Campbell, R.W., N.K. Dawe, I. McTaggart - Cowan, J.M. Cooper, G. Kaiser, and M.C.E. McNall. 1990. The birds of British Columbia. Vol. 1. Nonpasserines: introduction and loons through waterfowl. R. B.C. Mus., Victoria.
- Casebeer, R. L., M. J. Rognrud and S. M. Brandberg. 1950. Rocky Mountain goats in Montana. Montana Fish and Game Comm., Wildl. Rest. Div. Bull. No.5. 107 pp.
- Casey, D. 2000. Partners in Flight Draft Bird Conservation Plan Montana. Version 1.0. 287 pp.
- Caton, E. L., B. R. McClelland, D. A. Patterson, and R. E. Yates. 1992. Characteristics of foraging perches used by breeding Bald Eagles in Montana. Wilson Bulletin 104:136-142.
- Caton, E. L., et al. 1992. Characteristics of foraging perches used by breeding bald eagles in Montana. Wilson Bull. 104:136-142.
- Caton, E., M. Donofrio, and B. R. McClelland. 1989. Spring migration of a juvenile bald eagle from Glacier National Park, Montana: habitat use and management recommendations for the Missouri River. Unpubl. Rep., USDI National Park Serv., Glacier National Park, MT. 13 pp.
- Clark, T.W., H.A. Harvey, R.D. Dorn, D.L. Genter, and C. Groves (eds). 1989. Rare, sensitive, and threatened species of the greater Yellowstone ecosystem. Northern Rockies Conservation Cooperative, Montana Natural Heritage Program, The Nature Conservancy, and Mountain West Environmental Services. 153 p.
- Confluence Consulting Inc. 2010. Montana Department of Transportation Wetland Mitigation Monitoring Reports (various sites). MDT Helena, MT.
- Confluence Consulting Inc. 2011. Montana Department of Transportation Wetland Mitigation Monitoring Reports (various sites). MDT Helena, MT.
- Confluence Consulting Inc. 2012. Montana Department of Transportation Wetland Mitigation Monitoring Reports (various sites). MDT Helena, MT.
- Constan, Kerry, Dan Hook, and Rod Berg, 1981, Middle Missouri River Planning Project. FW-3-R-7. June 1981.
- Crenshaw, J. G. 1985. Characteristics of bald eagle communal roosts in Glacier National Park, Montana. M.S. thesis. University of Montana, Missoula. 92 pp.
- Crenshaw, J. G., and B. R. McClelland. 1989. Bald eagle use of a communal roost. Wilson Bull. 101:626-633.
- Curnutt, J. L. 1992. Dynamics of a year-round communal roost of bald eagles. Wilson Bull. 104:536-540.
- Donofrio, M. and B. Zinn 1990. Monitoring of resident and migrant bald eagle habitat use at Lake McDonald. P. 8 in Kathy Dimont, comp., Science in Glacier National Park, USDI National Park Service, Glacier National Park, MT. 52 pp.
- Dubois, K. 2003. Non-game Species Coordinator, Montana Fish, Wildlife, & Parks. Personal Communication regarding data from 2001 Bald Eagle nest monitoring data. Missoula, Montana. 406-542-5551.
- Dzus, E., and J. Gerrard. 1993. Factors influencing bald eagle densities in northcentral Saskatchewan. J. Wildlife Management 57:771-778.
- ECON, Inc. (Ecological Consulting Service), Helena, MT., 1977, Colstrip 10 x 20 Area wildlife and wildlife habitat annual monitoring report, 1977. Proj. 164-85-A. December 31, 1977.
- 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.
- Eng, R.L. and R.J. Mackie. 1996. Supplemental wildlife data collection: McDonald Gold Project.
- Erhlich, P.R., D.S. Doblin, and D. Wheye. 1992. Birds in jeopardy: the imperiled and extinct birds of the United States and Canada, including Hawaii and Puerto Rico. Stanford University Press, Stanford, California.
- Evans, D. L. 1982. Status reports on twelve raptors. U.S. Department of the Interior, Fish and Wildlife Service, Special Scientific Report No. 238. 68 pp.
- Farmer, Pat, and Dean Culwell, Westech, Inc. [Western Technology and Engineering], Helena, MT., 1981, Terrestrial wildlife reconnaissance. March 1981.
- Farmer, Patrick J., Western Technology & Eng., Inc., Helena, MT., 1996, Bald eagle nesting survey in the vicinity of the proposed McDonald Project. June 1996.
- Flath, D. L. 1983. Distribution, status, population recruitment, and habitat use of bald eagles in Montana. Job Prog. Rep., Endangered Species Proj. SE-l, Job 1. Montana Dept. Fish, Wildl. and Parks. 8 pp.
- Flath, D.L., R.M. Hazlewood, and A.R. Harmata. 1991. Status of the Bald Eagle (Haliaeetus leucocephalus) in Montana: 1990. Proceedings Montana Acadamy of Science. 51:15-32.
- Frost, J. E. 1985. Visitor perceptions of management restrictions during Glacier Park's bald eagle concentrations. M.S. thesis, University of Montana, Missoula. 69 pp.
- Garrett, M. G., J. W. Watson, and R. G. Anthony. 1993. Bald Eagle home range and habitat use in the Columbia River estuary. Journal of Wildlife Management 57:19-27.
- Gerrard, J. M., P. N. Gerrard, G. R. Bortolotti, and E. H. Dzus. 1992. A 24-year study of Bald Eagles on Besnard Lake, Saskatchewan. Journal of Raptor Research 26:159-166.
- Goodell, J. 2012. Morse Land Company Breeding Bird Inventory And Analysis. High Desert Museum. Bend, OR. 42 pp + Appendices.
- Green, N. 1985. The Bald Eagle. Pp 508-531 in R.L. DiSilvestro, ed., Audubon Wildlife Report 1985. National Audubon Society, New York.
- Griffin, C. R., T. S. Baskett, and R. D. Sparrowe. 1982. Ecology of bald eagles wintering near a waterfowl concentration. U.S. Fish and Wildlife Service Special Science Report - Wildlife No. 247:1-12.
- Grubb, T. G. 1995. Food habits of bald eagles breeding in the Arizona desert. Wilson Bulletin 107:258-274.
- Grubb, T.G., S. J. Nagiller, W. L. Eakle, and G. A. Goodwin. 1989. Winter roosting patterns of bald eagles (Haliaeetus leucocephalus) in north-central Arizona. Southwestern Naturalist 34:453-459.
- Grubb, T.G., W.W. Bowerman, and P.H. Howey. 1994. Tracking local and seasonal movements of wintering Bald Eagles Haliaeetus leucocephalus from Arizona and Michigan with satellite telemetry. Pages 247-358 IN B.-U. Meyburg and R. D. Chancellor, editors. Raptor conservation today. Pica Press, Moose Jaw, Saskatchewan.
- Harmata, A. R., and D. L. Flath. 1982. Behavior and ecology of wintering and migrant bald eagles in the Rocky Mountains. Job Prog. Rep., Endangered Species Proj. SE-l, Job 1. Montana Dept. Fish, Wildl. and Parks. 11 pp.
- Hawk Watch International. 2003. An online search for migration watch results, 1999-2002 data.
- Haywood, D. D., and R. D. Ohmart. 1986. Utilization of benthic-feeding fish by inland breeding bald eagles. Condor 88:35-42.
- Herkert, J. R., editor. 1992. Endangered and threatened species of Illinois: status and distribution. Vol. 2: Animals. Illinois Endangered Species Protection Board. iv + 142 pp.
- Humphris, Michael., 1990, Wildlife Monitoring Report. Spring Creek Coal Company 1990 Mining Annual Report. Appendix I. April 11, 1990.
- Humphris, Michael., 1991, Wildlife Monitoring Report. Spring Creek Coal Company 1991 Mining Annual Report. Appendix I. April 11, 1991.
- Jenkins, A.M. 1979. Bald eagle essential habitat on and near BLM lands in Wyoming. Animal Report 79. 34 pp.
- Jensen, K. C. 1988. Nest site selection by bald eagles in Montana. M. S. Thesis. Montana State University, Bozeman. pp 56.
- Johnsgard, P.A. 1990. Hawks, eagles, and falcons of North America. Smithsonian Institution Press, Washington, D.C. 403 pp.
- 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.
- Johnson, S. J., and T. Puchlerz. 1982. Hebgen Lake bald eagle management plan. USDA Forest Service. Gallatin National Forest. Hebgen Lake Ranger District. 15 pp.
- Kozie, K. D., and R. K. Anderson. 1991. Productivity, diet, and environmental contaminants in bald eagles nesting near the Wisconsin shoreline of Lake Superior. Arch. Environ. Contam. Toxicol. 20:41-48.
- Kralovec, M. L., et al. 1992. Nesting productivity, food habits, and nest sites of bald eagles in Colorado and southeastern Wyoming. Southwest. Nat. 37:356-361.
- LaVelle, Darlene. 1988. 1988 Nongame surveys in Region 5 and Region 7.' MTFWP. 40pp.
- 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.
- Lincer, J. L., W. S. Clark and M. N. LeFranc, Jr. 1979. Working bibliography of the bald eagle. Raptor Information Center, Nat. Wildlife Fed., Washington, D.C. NWF Scientific/technical Series No. 2. 219 pp.
- Livingston, S. A., et al. 1990. Habitat models for nesting bald eagles in Maine. J. Wildlife Management 54:644-653.
- 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.
- Mace, R.D., D. Casey and K. Dubois. 1987. Effects of water level fluctuations on productivity and distribution of Ospreys and Bald Eagles in the northern Flathead Valley. Montana Fish, Wildl. and Parks, for Montana Power Company, Butte. 90 pp.
- Magaddino, R. 1989. Living with bald eagles. Reprint from Montana Outdoors, July/August 1989. 3 pp.
- Mahaffy, M. S., and L. D. Frenzel. 1987. Elicited territorial responses of northern bald eagles near active nests. Journal of Wildlife Management 51:551-554.
- Matthews, W.L. 1981. Broadus-Pumpkin Creek baseline inventory - wildlife. Bureau of Land Management, Miles City, MT. 83 p.
- McClelland, B. R. 1967. Bald eagle concentrations in Glacier National Park. Unpubl. Rep., USDI National Park Service, Glacier National Park, MT. 11 pp.
- McClelland, B. R. 1981. Invesigation of the bald eagle concentrations along McDonald Creek, Glacier National Park. P. 9 in ResearchlManagement Rep. Series No.3, USDI National Park Service, Glacier National Park, MT. 13 pp.
- McClelland, B. R. 1982. McDonald Creek's bald eagles: an international resource. Montana Outdoors 13(6):2-6.
- McClelland, B. R. 1986. Glacier National Park bald eagle research project: progress report for 1984 and 1985. U. of Montana, School of Forestry, Missoula. 14 pp.
- McClelland, B. R. 1990. Bald eagles and salmon. P. 202 in Birds of Prey. I. Newton, ed., Weldon Owen, Inc., New South Wales, Australia.
- McClelland, B. R. and D. S. Shea. 1977. Local and long-range movements of bald eagles associated with autumn concentrations in Glacier National Park. Pp. 29-30 in K. L. McArthur (compiler), 1976 Annual Research Summary, USDI National Park Service, Glacier National Park, Unpubl. Rep., Glacier National Park, MT. 64 pp.
- McClelland, B. R. and D. S. Shea. 1978. Local and long-range movements of bald eagles associated with autumn concentrations in Glacier National Park. Pp. 36-38 in K. L. McArthur, ed., 1977 Annual Research Summary, Glacier National Park, Unpubl. Rep., USDI National Park Serv., Glacier National Park, MT. 62 pp.
- McClelland, B. R. and P. T. McClelland 1990. The autumn concentration of bald eagles in Glacier National Park - ecology and management recommendations. Pp. 7-8 in Kathy Dimont, comp., Science in Glacier National Park, Glacier Natural History Association. 52 pp.
- McClelland, B. R. and R. E. Yates. 1989. Nesting ecology of bald eagles in Glacier National Park. Pp. 9-10 in Kathy Dimont, comp., 1989 Science Summary, Glacier National Park, Glacier Natural History Assoc., West Glacier, MT. 49 pp.
- McClelland, B. R., and P. T. McClelland. 1986. Bald eagles and kokanee salmon: a rendezvous in Glacier National Park. Western Wildlands 11(4):7-11.
- McClelland, B. R., D. S. Shea, H. L. Allen, and E. B.Spettigue. 1979. Movement patterns, morphology, and numbers of bald eagles associated with the autumn concentration in Glacier National Park, Montana. Proc. of the Second Conference on Scientific Research in the National Parks, 1979, San Francisco. 12 pp.
- McClelland, B. R., E. Caton, and R. E. Yates 1990. Characteristics of nest, perch, and roost trees and associated forest stands within home ranges of nesting bald eagles. P. 6. in Kathy Dimont, comp., Science in Glacier National Park, Glacier Natural History Assoc. 52 pp.
- McClelland, B. R., E. Caton, and R. E. Yates. 1988. Research progress rep. and recommendations for an interim site-specific management plan: logging lake bald eagle territory. Unpubl. progress rep., Glacier National Park, West Glacier, MT. 10 pp.
- McClelland, B. R., L. S. Young, D. S. Shea, P. T. McClelland, H. L. Allen and E. B. Spettigue. 1983. The bald eagle concentration in Glacier National Park, Montana: an international perspective for management. Pp. 69-77 in D. M. Bird, ed., Biology and management of bald eagles and ospreys. Harpell Press, Ste. Ann de Bellevue, Quebec.
- McClelland, B. R., L. S. Young, D. S. Shea, P. T. McClelland, H. L. Allen, and E. B. Spettigue. 1982. The Bald Eagle concentration in Glacier National Park: Origin, growth, and variation in numbers. Living Bird 19:133-155.
- McClelland, B. R., P. T. McClelland and J. G. Crenshaw. 1983. Long-range movements of bald eagles from the autumn concentration in Glacier National Park, Montana. Prog. Rep. USDI National Park Service, Glacier National Park. 20 pp.
- McClelland, B. R., P. T. McClelland, and J. G. Crenshaw. 1982. Movements of bald eagles from the autumn concentration in Glacier National Park, MT, 1981-1982 progress Rep., Unpubl. Rep., USDI National Park Service, Glacier National Park, MT. 20 pp.
- McClelland, B. R., P. T. McClelland, and J. G. Crenshaw. 1984. Ecology of bald eagles associated with the autumn concentration in Glacier National Park, Montana. Prog. Rep., USDI National Park Serv., and School of For., University of Montana, Missoula. 85 pp.
- McClelland, B. R., R. E. Yates, E. Caton, M. McFadzen, and P. T. McClelland. 1990. Nesting ecology of bald eagles. P. 7 in Kathy Dimont, comp, Science in Glacier National Park, 1990, Glacier Natural History Assoc., West Glacier, MT. 52 pp.
- McClelland, B.R. 1973. Autumn concentrations of bald eagles in Glacier National Park. Condor 75:121-123.
- McClelland, B.R. 1981. Management of people at the autumn concentration of bald eagles in Glacier National Park, Montana. pp. 237-240. In: Eagle Valley Environ. Tech. Rep. BED81.
- McClelland, P. 1989. Bald eagle survey, Kootenai National Forest, spring 1989, final report. Unpublished report. 17 pp. plus maps.
- McClelland, P.T. 1992. Ecology of bald eagles at Hungry Horse Reservoir, Montana. M.S. thesis, University of Montana, Missoula. 94 pp.
- Montana Bald Eagle Working Group. 1991. Habitat management guide for bald eagles in northwestern Montana. 29 p.
- Montana Bald Eagle Working Group. 1994. Montana Bald Eagle Management Plan, 2nd edition. U.S. Bureau of Reclamation, Montana Projects Office, Billings, Montana. 104pp.
- Montana Bird Distribution Committee. 2012. P.D. Skaar's Montana bird distribution. 7th Edition. Montana Audubon, Helena, Montana. 208 pp. + foldout map.
- Montana Bird Distribution Online Database. 2001. Helena, Montana, USA. April-September 2003.
- Montana Dept. of Fish, Wildlife and Parks. Region Four., 1996, Draft Environmental Analysis for Weed Management.
- Montana Dept. of Natural Resources and Conservation, 1979, Kootenai Falls Wildlife Inventory and Impact Analysis. Final Report, for the period January 1, 1978 - September 1, 1979; October 1979.
- Montopoli, G. J., and D. A. Anderson. 1991. A logistic model for the cumulative effects of human intervention on bald eagle habitat. J. Wildlife Management 55:290-293.
- Northrop, Devine and Tarbell, Inc. 1995. Cabinet Gorge and Noxon Rapids Hydroelectric Developments, 1994 Wetland Mapping and Assessment Study, Volume I of II. 27 pp. plus appendices.
- Olendorff, Richard R., and Robert N. Lehman, USDI Bureau of Land Management., 1986, Raptor collisions with utility lines: An Analysis using subjective field observations. Final Report. February 1986.
- Palmer, R. S., editor. 1988. Handbook of North American birds. Vol. 4. [Diurnal raptors, part 1]. Yale University Press, New Haven. vii + 433 pp.
- Restani, M. and A.R. Harmata. 1992. Survey of raptors along the upper Missouri River, Montana. Montana State University. Bozeman, MT. 53 pp plus appendix.
- Rogers, Ralph and Jay Sumner. 2004. Montana Peregrine Falcon Survey. Centmont Bioconsultants. Winifred, Montana. 32 pp plus appendix.
- 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.
- Shea, D. S. 1978. Bald Eagle concentrations in Glacier National Park. Western Birds 9:35-37.
- Shea, D. S. 1973. A management-oriented study of bald eagle concentrations in Glacier National Park. M.S. thesis. University of Montana, Missoula, 78 pp.
- Shea, D. S. 1978. Some observations on bald eagle concentrations in Glacier National Park. UnpubI. Rep., USDI National Park Service, Glacier National Park, MT. 7 pp.
- Sibley, C.G., and B. L. Monroe. 1990. Distribution and taxonomy of birds of the world. Yale Univ. Press, New Haven. xxiv + 1111 pp.
- 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.
- Steenhof, K. 1978. Management of wintering bald eagles. U.S. Fish and Wildlife Service, FWS/OBS-79/79, 55 pp.
- Sumner, J. and R. Rogers. 1999. Montana Peregrine Falcon Survey. prepared for Montana Fish, Wildlife & Parks. 27pp. (plus maps and photos).
- Sumner, J. and R. Rogers. 2001. Montana Peregrine Falcon Survey. prepared for Montana Fish, Wildlife & Parks. 22 pp.
- Sumner, J. and R. Rogers. 2002. Montana Peregrine Falcon Survey. prepared for Montana Fish, Wildlife & Parks. 29 pp plus appendix.
- Sumner, Jay and Ralph Rogers. 2006. Montana Peregrine Falcon Survey. Montana Peregrine Institute. Arlee, Montana. 36 pp plus appendix.
- Swenson, J. E. 1975. Ecology of the bald eagle and osprey in Yellowstone National Park. Thesis. Bozeman, Montana: Montana State University. 146 p.
- Swenson, J. E., T. C. Hinz, S. J. Knapp, H. J. Wentland, and J. T. Herbert. 1981. A survey of wintering Bald Eagles in southeastern Montana. Raptor Research 15(4):113-120.
- Swenson, J.E., K.L. Alt, and R.L. Eng. 1986. Ecology of Bald Eagles in the greater Yellowstone ecosystem. [Washington, D.C.]: Wildlife Society Monographs 95:1-46.
- Terres, J.K. 1980. The Audubon Society encyclopedia of North American birds. Alfred A. Knopf, New York. 1109 pp.
- TVX Mineral Hill Mine, Amerikanuak, Inc., Gardiner, MT., 2002, Yearly summary of wildlife observation reports. 1990-2002 Letter reports.
- U.S. Fish & Wildlife Service., 1984, Charles M. Russell National Wildlife Refuge, Montana: Draft Environmental Impact Statement.
- U.S. Fish & Wildlife Service., 1985, Charles M. Russell National Wildlife Refuge, Montana: Final Environmental Impact Statement.
- U.S. Fish and Wildlife Service. 1980. Management of Charles M. Russell National Wildlife Refuge. Draft. Reprint
- U.S. Fish and Wildlife Service. 1999. Proposed rule to remove the Bald Eagle in the lower 48 states from the list of endangered and threatened wildlife. Federal Register 64:36453-36464.
- U.S. Forest Service, Kootenai National Forest. Montana Dept. of State Lands., 1978?, Final Environmental Impact Statement. Proposed Plan of Mining and Reclamation. Troy Project, Asarco, Inc., Lincoln County, Montana. Vol. III.
- 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.
- USDI National Park Service. 1978. Bald eagle management plan, 13 March 1978. Unpubl. Rep., Glacier National Park, MT. 13 pp.
- USDI National Park Service., 2000, Bison Management for the State of Montana and Yellowstone National Park. Final Environmental Impact Statement for the Interagency Bison Management Plan for the State of Montana and Yellowstone National Park. Vol. I. August 2000.
- Waage, B.C. 1984. Western Energy Company Rosebud Mine, Rosebud County, Montana: Annual Wildlife Monitoring Report, 1983 Field Season. June 1984.
- Waage, B.C. 1986. Western Energy Company Rosebud Mine, Rosebud County, Montana: Annual Wildlife Monitoring Report, 1985 Field Season. December 1985.
- Waage, Bruce C., 1993, Western Energy Company Rosebud Mine, Colstrip, Montana: Annual Wildlife Monitoring Report; 1993 Field Season. April 1993.
- Waage, Bruce C., compiler., 1985, Western Energy Company Rosebud Mine, Rosebud County, Montana: Annual Wildlife Monitoring Report, 1984 Field Season. October 1985.
- Watson, J. W., M. G. Garrett, and R. G. Anthony. 1991. Foraging ecology of bald eagles in the Columbia River estuary. J. Wildlife Management 55:492-499.
- Western EcoTech, Helena, MT., 1999, Wetland delineation report for the Haskins Landing Proposed Wetland Mitigation Area. MWFE? June 2, 1999.
- Western Energy Co., Colstrip, MT., 1981, Western Energy Company Rosebud Mine, Colstrip, Montana: Annual Wildlife Report, 1981.
- Western Energy Co., Colstrip, MT., 1982, Western Energy Company Rosebud Mine, Colstrip, Montana: Annual Wildlife Report, 1982.
- Westmoreland Resources, Inc., Hardin, MT., 1983, 1980 Wildlife Monitoring Report. 12/21/79-12/20-80.
- Wiemeyer, S. N., R. W. Frenzel, R. G. Anthony, B. R. McClelland, and R. L. Knight. 1989. Environmental contaminants in blood of western Bald Eagles. Journal of Raptor Research 23:140-146.
- Witmer, G., and T. A. O'Neil. 1990. Assessing cumulative impacts to wintering bald eagles in western Washington. Pages 144-150 in Mitchell et al., eds. Ecosystem management: rare species and significant habitats. New York State Museum Bull. 471.
- Wood, P. B., T. C. Edwards, Jr., and M. W. Collopy. 1989. Characteristics of bald eagle nesting habitat in Florida. J. Wildlife Management 53:441-449.
- Wright, M. And R. E. F. Escano. 1986. Montana Bald Eagle Nesting Habitat, Macro-Habitat Description. USDA FS, Northern Region, Missoula, MT. WFHR Unnumbered Rept. 30 pp.
- Wright, M. F. 1986. Simulating the search image of nesting bald eagles in western. Montana: a management model. Unpubl. Rep., University of Montana, Missoula. 26 pp.
- Yates, R. E, B. R. McClelland, and C. Key. 1992. Graphic depiction of bald eagle use patterns in Montana. Proc. of the Symp. On bald eagles in Alaska, Juneau.
- Yates, R. E. 1988. Nesting ecology of bald eagles in Glacier National Park. M.S. thesis, University of Montana, Missoula.
- Yates, R. E. 1989. Bald eagle nesting ecology and habitat use: Lake McDonald, Glacier National Park, Montana. M.S. thesis. University of Montana, Missoula. 102 pp.
- Yates, R. E. 1989. Bowman Lake bald eagle territory summary of observations during 1989. Unpubl. Rep., USDI National Park Service, Glacier National Park, MT. 6 pp.
- Yates, R. E., and B. R. McClelland. 1989. Unusual injury to a nestling bald eagle. J. Raptor Research 23(1): 14-16.
- Young, L. S. 1983. Movements of bald eagles associated with autumn concentrations in Glacier National Park. M.S. thesis. University of Montana, Missoula. 102 pp.
- Young, L. S., B. R. McClelland, H. L. Allen, P. T. McClelland, and J. G. Crenshaw. 1983. Long-range movements of bald eagles associated with the autumn concentration in Glacier National Park, Montana: a preliminary report. P. 325 in D. M. Bird, ed., Biology and management of bald eagles and ospreys. Harpell Press, Ste. Anne de Bellevue, Quebec.
- Zubik, R. J. 1988. A site specific management plan for the lower Stillwater bald eagle territory. [Unpublished report]. Montana Department of Fish, Wildife, and Parks, Kalispell. 43 PP.
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