Prairie Falcon - Falco mexicanus
Sexes are similar in color, uniformly buffy brown above and creamy white below. The tail is rufous-brown with very fine barring. Adults have a brown-barred breast and belly, while juveniles have more boldly brown-streaked under-parts. Both adults and young have dark brown feathers on the undersides of the wings near the body ("wing pits"), and a dark brown stripe running diagonally backward from below the eye. The eye is dark brown. Average length 39 to 50 cm, wingspan 89 to 109 cm; males average about 15 inches in length and have a wingspan of about 37 inches in length, and females average about 17 inches in length with a wingspan of about 41 inches. A medium-sized falcon with pointed wings, a hooked bill, and conspicuous (in flight) dark patches near the body on the underside of the wings (axillaries and coverts).
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.
Prairie Falcons are about the same size as juvenile Peregrine Falcons, but lighter in color and lack the heavy dark wedge on the side of the face of the Peregrine Falcon. They are much smaller than Gyrfalcons, and much larger and lighter in color than female Merlins. Differs from all other North American falcons in having dark patches in the wingpits.
Western Hemisphere Range
Summary of Observations Submitted for Montana
Number of Observations:
(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)
Migration southward and eastward from Montana nesting areas is common (FWP). Bozeman area: wintering birds arrive November 1 to November 15 and leave by March 25 (Skaar 1969).
Prairie Falcons use cliffs for nesting, and grassland and prairie habitats for hunting. 83% nesting territories located between 4000 and 6000 ft. Most nests are on cliffs averaging 125 ft in height. Mean height above base of cliff was 80 ft. 72% of eyries faced south or east. Almost all nests overlooked at least some grassland (Leedy 1972).
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 firstname.lastname@example.org
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
Human Land Use
Recently Disturbed or Modified
Shrubland, Steppe and Savanna Systems
Sparse and Barren Systems
Wetland and Riparian Systems
- Occasionally Associated with these Ecological Systems
Forest and Woodland Systems
Recently Disturbed or Modified
Wetland and Riparian Systems
Prairie Falcons feed primarily on birds and mammals, often exploiting locally abundant prey populations. In Montana, common prey are Western Meadowlarks, Horned Larks, and ground squirrels. Western MT: Richardson's Ground Squirrels (Citellus ricardsonii) and Horned Larks (Eremophilia alpestris) were most common prey at eyries, with Western Meadowlarks (Stornella neglecta) next in abundance (Leedy 1972).
Nests sites are on cliffs, usually in a large hole or sheltered ledge, or sometimes in stick nests built by Golden Eagles or hawks. Adults establish nesting territories in late March or early April, and noisy aerial courtship displays are common. Clutches of three to five eggs are usually laid in late April, and incubated for about one month. Young leave the nest when about 40 days old, but may stay nearby for up to four weeks afterward. Pairing occurred April 1; completion of clutches April 10 to May 14; hatching May 9 to June 12; fledging June 15 to July 21. Mean no.'s: eggs/clutch 4.3; fledglings/success/pair 2.9; fledglings/territory 1.9; young fledged/nesting attempt 0.9 (Leedy 1972).
- Literature Cited AboveLegend: View Online Publication
- Leedy, R. R. 1972. The status of Prairie Falcons in western Montana: Special emphasis on possible effects of chlorinated hydrocarbon insecticides. M.S. thesis, University of Montana, Missoula.
- Marks, J.S., P. Hendricks, and D. Casey. 2016. Birds of Montana. Arrington, VA. Buteo Books. 659 pages.
- 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.
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?
- Allen, G. T. 1979. An assessment of potential conflicts between nesting raptors and human activities in the Long Pines area of southeastern Montana with special emphasis on uranium development. M.S. thesis, Washington State University, Pullman. 109 pp.
- Allen, G. T. 1987. Estimating prairie falcon and golden eagle nesting populations in North Dakota. The Journal of Wildlife Management. 51(4):711-715.
- Allen, G. T. 1987. Prairie falcon aerie site characteristics and aerie use in North Dakota. Condor 89: 187-190.
- American Ornithologists’ Union [AOU]. 1998. Check-list of North American birds, 7th edition. American Ornithologists’ Union, Washington, D.C. 829 p.
- Beak Consultants, Inc., Portland, OR., 1983, Wildlife. January 1983. In Stillwater Project Environmental Studies. Addendum A, Wildlife. Vol. I. Tech. Report No. 7. 1982.
- Bechard, Mark. 1986. Early Montana naturalists and oologists. Blue Jay. 44(1):20-30.
- Becker, D. M. 1981. Development of artificial nest sites for prairie falcons -- progress report. Montana Coop. Wildl. Res. Unit. 8 pp.
- Becker, D.M. and Holt, D.W. 1982. A survey of raptor breeding activity and habitat utilization along the Missouri River in North Central Montana with special emphasis on Peregrine and Prairie Falcons.
- Becker, Dale M., 1980, A Survey of raptors on national forest land in Carter County, Montana. Final Progress Report: 1977-1979.
- Beebe, F.L. 1974. Field studies of the Falconiformes of British Columbia. Occ. Paper Series, British Columbia Prov. Mus., No. 17. British Columbia Provincial Museum, Victoria. 163 pp.
- Bramblett, Robert G., and Alexander V. Zale. 2002. Montana Prairie Riparian Native Species Report. Montana Cooperative Fishery Research Unit, Montana State University - Bozeman.
- Casey, D. 2005. Rocky Mountain Front avian inventory. Final report. Prepared for the U.S. Fish and Wildlife Service and The Nature Conservancy by the American Bird Conservancy, Kalispell, Montana.
- Decker Coal Co., 1981, Wildlife survey. July 7, 1981. In North Decker 5-Year Permit Application. Vol. III. Rule 26.4.304(12-14).
- Decker Coal Company., 1991, Decker Coal Company West Pit Permit. Vol. 3. 26.4.304(10-11), 305, 306, and 307. Updated Rules Rewrite, July 1, 1991.
- 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.
- Dood, A.R. 1980. Terry Badlands nongame survey and inventory final report. Montana Department of Fish, Wildlife, and Parks and Bureau of Land Management, Helena, MT. 70 pp.
- Dubois, K. 1988. Kevin Rim/Sweetgrass Hills raptor survey. Bureau of Land Management. 8 pp. plus data appendices.
- 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.
- ECON, Inc. (Ecological Consulting Service), Helena, MT., 1979, Annual wildllife report of the Colstrip Area for 1978. Proj. 195-85-A. April 6, 1979.
- ECON, Inc. (Ecological Consulting Service), Helena, MT., 1979, Annual wildllife report of the Colstrip Area for 1979, including a special raptor research study. Proj. 216-85-A. March 1, 1980.
- 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.
- Enderson, J. H. 1964. A study of the Prairie Falcon in the central Rocky Mountain region. Auk 81:332-352.
- 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.
- Flath, Dennis and David Dickson. 1994 Systematic wildlife observations on the Blackfoot-Clearwater Wildlife Management Area 1991-1993. Montana Department of Fish, Wildlife and Parks.
- Gniadek, Steve. 1983. Southwest Glendive Wildlife Baseline Inventory. BLM, Miles City District. 56pp with appendices.
- Goodell, J. 2012. Morse Land Company Breeding Bird Inventory And Analysis. High Desert Museum. Bend, OR. 42 pp + Appendices.
- Gorman, J. D., 1984, Interagency Rocky Mountain Front Wildlife Monitoring/Evaluation Program.
- 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.
- Harmata, Al and Jaffe, Rose. 2003. Success and Productivity of Key Raptor Species Nesting in the Kevin Rim Raptor Study Area, 2002-2003. Challenge Cost Share Progress report to BLM Great Falls District.
- Harmata, Al and Rose Jaffe. 2001. Population Dynamics of Key Raptor Species in the Kevin Rim Raptor Study Area, 2001. Challenge cost share progress report to: Bureau of Land Management Great Falls District. Department of Ecology Fish and Wildlife Program. Montana State University. Bozeman, MT.
- Hendricks, P., and K.H. Dueholm. 1995. Cliff-nesting raptor survey of the Sioux District, Custer National Forest: 1994. Unpubl. report to U.S.D.A. For. Serv., Custer N.F., Billings. 20 pp.
- Humphris, Michael., 1990, Wildlife Monitoring Report. Spring Creek Coal Company 1990 Mining Annual Report. Appendix I. April 11, 1990.
- 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.
- Kevin Rim Raptor Study Group. 1991. Impacts of oil and gas development on raptors associated with Kevin Rim, Montana. Unpublished report for the Bureau of Land Management, Great Falls. 37pp.
- 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.
- Lockhart, J. Michael, and Terrence P. McEneaney, 1978, Effects of coal extraction and related development on wildlife populations. Annual progress report; Calendar year 1978. 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.
- Lockhart, J. Michael, Terrence P. McEneaney, and Albert L. Harting, Jr., 1977, Effects of coal extraction and related development on wildlife populations. Annual progress report; Calendar year 1977. 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.
- MacLaren, P. A. , D.E. Runde, and S. H. Anderson. 1984. A record of tree-nesting Prairie Falcons in Wyoming. Condor 86:12-18.
- Matthews, W.L. 1980a. Wibaux-Beach comparison study: Sydney, Glendive and Plevna Study Areas. Bureau of Land Management, Miles City, MT. 50 p.
- Matthews, W.L. 1981. Broadus-Pumpkin Creek baseline inventory - wildlife. Bureau of Land Management, Miles City, MT. 83 p.
- Maxim Technologies, Inc., 2002, Western Energy Company Rosebud Mine, Colstrip, Montana: 2002 Annual Wildlife Monitoring Report; December 1, 2001 - November 30, 2002. Febr. 24, 2002.
- Montana Bird Distribution Committee. 2012. P.D. Skaar's Montana bird distribution. 7th Edition. Montana Audubon, Helena, Montana. 208 pp. + foldout map.
- Montana Dept. of State Lands (Montana Dept. of Natural Resources and Conservation). U.S. Dept. of the Interior. U.S. Office of Surface Mining, 1985, Draft Environmental Impact Statement. Western Energy Company's Rosebud Mine Area D; January 1985.
- Montana Dept. of State Lands. U.S. Office of Surface Mining Reclamation and Enforcement., 1988, Draft Environmental Impact Statement. Peabody Coal Company's Big Sky Area B Mine, Rosebud County, Montana; July 1988.
- Montana Prairie Dog Working Group. 2002. Conservation plan for black-tailed and white-tailed prairie dogs in Montana. Montana Fish, Wildlife and Parks. Helena MT. 51 pp.
- Moritsch, M. Q. 1983. Photographic guide for aging nestling Prairie Falcons. USDI Bureau of Land Management, Snake River Birds of Prey Project. Boise District, ID.
- Phillips, R.L., A.H. Wheeler, N.C. Forrester, J.M. Lockhart, and T.P. McEneaney. 1990. Nesting ecology of golden eagles and other raptors in southeastern Montana and northern Wyoming. U.S. Fish Wildl. Serv. Tech. Rep. 26:1-13.
- Powder River Eagle Studies, Inc., Gillette, WY., 1996, Spring Creek Mine 1995 Wildlife Monitoring Studies. Spring Creek Coal Company 1995-1996 Mining Annual Report. Vol. I, App. I. May 1996.
- Powder River Eagle Studies, Inc., Gillette, WY., 2000, Spring Creek Mine 1999 Wildlife Monitoring. March 2000.
- 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.
- Roppe, J. A., S. M. Siegel, and S. E. Wilder. 1989. Prairie Falcon nesting on transmission towers. Condor 91:711-712.
- 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.
- Runde, D. E. and S. H. Anderson. 1986. Characteristics of cliffs and nest sites used by breeding Prairie Falcons. Raptor Res. 20:21-28.
- 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.
- Snow, C. 1974. Habitat management series for unique or endangered species, Report No. 8, Prairie Falcon, Falco mexicanus. Bureau of Land Management, U.S. Department of Interior Technical Note, T-N-240, Denver.
- Steenhof, K. 1998. Prairie Falcon (Falco mexicanus). Species Account Number 346. 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
- Stewart, R.E. 1975. Breeding birds of North Dakota. Tri-College Center for Environmental Studies, Fargo, North Dakota. 295 pp.
- Suter, G. W., II and J. L. Joness. 1981. Criteria for Golden Eagle, Ferruginous Hawk, and Prairie Falcon nest site protection. Raptor Res. 15:12-18.
- Thomas, J. W. (ed). 1979. Wildlife habitats in managed forests: the Blue Mountains of Oregon and Washington. Agriculture Handbook 553, USDA, Forest Service, Wildlife Management Institute, Washington, DC. 512 pp.
- Thompson, Richard W., Western Resource Dev. Corp., Boulder, CO., 1996, Wildlife baseline report for the Montana [Montanore] Project, Lincoln and Sanders counties, Montana. In Application for a Hard Rock Operating Permit and Proposed Plan of Operation, Montanore Project, Lincoln and Sanders Counties, Montana. Vol. 5. Stroiazzo, John. Noranda Minerals Corp., Libby, MT. Revised September 1996.
- 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.
- Vanderhorst, J.P. 1993. Rapid ecological assessment of selected state lands in southcentral Montana for plant species of special concern. Unpublished report to the Montana Department of Fish, Wildlife and Parks, Parks Division, Region Five. Montana Natural Heritage Program, Helena, MT. 30 pp.
- Waage, Bruce C., 1987, Western Energy Company Rosebud Mine, Colstrip, Montana: Annual Wildlife Monitoring Report, 1987 Field Season. December 1987.
- Waage, Bruce C., 1988, Western Energy Company Rosebud Mine, Colstrip, Montana: Annual Wildlife Monitoring Report, 1988 Field Season. December 1988.
- Waage, Bruce C., 1989, Western Energy Company Rosebud Mine, Colstrip, Montana: Annual Wildlife Monitoring Report, 1989 Field Season. December 1989.
- Waage, Bruce C., 1992, Western Energy Company Rosebud Mine, Colstrip, Montana: Annual Wildlife Monitoring Report, 1991 Field Season. December 1992.
- Waage, Bruce C., 1993, Western Energy Company Rosebud Mine, Colstrip, Montana: Annual Wildlife Monitoring Report; 1992 Field Season. December 1993.
- Waage, Bruce C., 1993, Western Energy Company Rosebud Mine, Colstrip, Montana: Annual Wildlife Monitoring Report; 1993 Field Season. April 1993.
- Waage, Bruce C., 1995, Western Energy Company Rosebud Mine, Colstrip, Montana:1994 Annual Wildlife Monitoring Report; December 1, 1993 - November 30, 1994. February 27, 1995.
- Waage, Bruce C., 1998, Western Energy Company Rosebud Mine, Colstrip, Montana: 1997 Annual Wildlife Monitoring Report; December 1, 1996 - November 30, 1997 Survey Period. March 23, 1998.
- Waage, Bruce C., 1999, Western Energy Company Rosebud Mine, Colstrip, Montana: 1998 Annual Wildlife Monitoring Report; December 1, 1997 - November 30, 1998 Survey Period. February 24, 1999.
- Waage, Bruce C., 2002, Western Energy Company Rosebud Mine, Colstrip, Montana. 2001 Annual Wildlife Monitoring Report; December 1, 2000 - November 30, 2001. Febr. 26, 2002.
- Waage, Bruce C., compiler., 1984, Western Energy Company Rosebud Mine, Rosebud County, Montana: Annual Wildlife Monitoring Report, 1983 Field Season. June 1984.
- Waage, Bruce C., compiler., 1985, Western Energy Company Rosebud Mine, Rosebud County, Montana: Annual Wildlife Monitoring Report, 1984 Field Season. October 1985.
- Waage, Bruce C., compiler., 1986, Western Energy Company Rosebud Mine, Rosebud County, Montana: Annual Wildlife Monitoring Report, 1985 Field Season. December 1986.
- Waage, Bruce C., compiler., 1986, Western Energy Company Rosebud Mine, Rosebud County, Montana: Annual Wildlife Monitoring Report, 1986 Field Season. December 1986.
- 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., 1980, Western Energy Company Rosebud Mine, Colstrip, Montana: Annual Wildlife Report, 1980.
- Western Energy Co., Colstrip, MT., 1981, Western Energy Company Rosebud Mine, Colstrip, Montana: Annual Wildlife Report, 1981.
- Western Energy Co., Colstrip, MT., 1981, Western Energy Company's Application for a Surface Mining Permit: Area C - Block 1. Vol. 1. May 1981.
- 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
- Western Technology and Eng., Inc., 1991, Wildlife resources of the Little Rocky Mountains Environmental Study Area. March 1991. In Application for Amendment to Operating Permit No. 00096, Zortman Mining, Inc., Phillips County, Montana. Vol. 3. Jan. 3, 1995.
- Western Technology and Eng., Inc., Helena, MT., 1996, Terrestrial Wildlife Reconnaissance: Stillwater Mining Company Hertzler Tailings Facility and Tailings Line, 1996. October 1996. In Stillwater Mining Co. Mine Waste Management Plan Amendment to Permit #00118 Supplemental Baseline Reports: Terrestrial Wildlife, Vegetation, Soils, Land Application Disposal, Waters of the U.S. January 1997.
- Western Technology and Engineering, Inc. (WESTECH)., 1993, Wildlife Monitoring Asaloka Mine Area Annual Report, 1992. Montana SMP 85005 R1. OSMP Montana 00078. 1993.
- Western Technology and Engineering, Inc. (WESTECH)., 2001, Wildlife Monitoring Absaloka Mine Area Annual Report, 2000. Montana SMP 85005. OSMP Montana 0007E. February 2001.
- Westmoreland Resources, Inc., Hardin, MT., 1983, 1980 Wildlife Monitoring Report. 12/21/79-12/20-80.
- Westmoreland Resources, Inc., Hardin, MT., 1983, 1983 Wildlife Monitoring.
- Wright, M. 1985. Prairie falcon and peregrine falcon survey on the Flathead Indian Reservation. University of Montana, Missoula. 81 pp.
- Zelenak, J. R. 1996. Breeding ecology of Ferruginous Hawks at the Kevin Rim in northern Montana. M.S. thesis, Montana State University, Bozeman.
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