Burrowing Owl - Athene cunicularia
State Rank Reason (see State Rank above)
Species has a negative short-term population trend.
- Details on Status Ranking and Review
ScoreU - Unknown
ScoreG - 200,000-2,500,000 km squared (about 80,000-1,000,000 square miles)
Comment310,345 square kilometers based on Natural Heritage Program range maps that appear on the Montana Field Guide
Area of Occupancy
ScoreU - Unknown
ScoreD - Moderate Decline (decline of 25-50%)
CommentProbably have lost >25% of prairie dog habitat in Montana since European arrival. Extirpated from B.C. where reintroduction efforts have reestablished small numbers. Also, range has contracted in Minnesota and other portions of Canada. Evidence suggests populations have declined due to habitat loss, pesticides, predators, and vehicle collisions. Human shooting and nest burrow disturbance have been a significant problem in some areas.
ScoreD/E - Either stable, or declining with a decline of 10-30% in population, range, area occupied, and/or number or condition of occurrences
CommentBreeding Bird Survey (BBS) data for Montana is of very moderate credibility and shows an insignificant negative trend from 1966 to 2009 of -1.6% per year or -15% decline per decade. Between 1999 and 2009 there is an insignificant +2% increase per year or a +22% increase per decade. Most surrounding states and provinces east of the Continental Divide with credible data show evidence for declines. Thus, the short-term trend is probably best regarded as negative.
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.
CommentDeclines of prairie dog populatoins due to plague and anthropogenic factors is the greatest threat to the species. Evidence suggests populations have declined due to habitat loss, pesticides, predators, and vehicle collisions. Human shooting and nest burrow disturbance have been a significant problem in some areas. Vehicle collisions result from owls sitting on roads at night while hunting.
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 should recover from declines within 10-50 years if burrow habitats and/or prairie dogs are present.
ScopeModerate - 20-60% of total population or area affected
Comment>20% of prairie dog habitat is being impacted or threatened.
ImmediacyModerate - Threat is likely to be operational within 2-5 years.
ScoreC - Not Intrinsically Vulnerable. Species matures quickly, reproduces frequently, and/or has high fecundity such that populations recover quickly (< 5 years or 2 generations) from decreases in abundance; or species has high dispersal capability such that extirpated populations soon become reestablished through natural recolonization (unaided by humans).
CommentNot Intrinsically Vulnerable. Species matures quickly, reproduces frequently, and/or has a high fecundity such that populations recover quickly (< 5 years or 2 generations) from decreases in abundance. Species has good dispersal capabilities such that extirpated populations generally become reestablished through natural recolonization.
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. Dependent on burrow habitats which are still widespread because prairie dogs are fairly widespread.
Raw Conservation Status Score
3.5 + 0.0 (geographic distribution) + 0.0 (environmental specificity) -0.25 (short-term trend) + 0.0 (threats) = 3.25
Burrowing Owls are probably most distinguishable because of their ground-dwelling behavior. They may also be identified by their long legs, round, tuft-less head, and bright yellow eyes. The distinct oval facial ruff is framed by a buffy white eyebrow-to-malar stripe near the bill (Haug et al. 1993). The primary feathers of their relatively long, rounded wings are brown with buffy-white barring. Their tail is short and also decorated with this same brown with buffy-white barring. The back, scapulars, and crown are brown with buffy-white spotting (Haug at al. 1993). The underparts are a buffy-white with broad brown barring, while the throat and undertail coverts are white (Haug et al. 1993). The bill is pale, cream colored to yellowish-white or greenish-yellow (Haug et al. 1993). As with other owl species, females may be darker than males, especially in worn plumage. Juveniles are similar to the adults, except the head is plain brown, the upper chest has a dark tan band, and the lower chest and belly are light-to-white in color.
This owl averages 24 cm (9.5 inches) long with a wingspan of 53 cm (21 inches), and a weight of approximately 155 grams (5 onces) (Sibley 2000).
The male call is described as a high nasal trumpeting "coo-coo",
which may be answered by the female with a short clear "eeep"
or a harsh rasping "ksshh"
(Sibley 2000). A rasping alarm call is made by both sexes. Vocalizations heard year round include short, sharp husky "chuk"
or a series of barking notes, with a rasping scream described as "kwee-ch-ch-ch-ch"
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.
Burrowing Owls can be identified from other owl species by the fact that they live in the ground. They are found in open grassland habitat where they nest and roost in abandoned animal burrows. In addition to perching on the lip of their prairie burrows, these owls may be observed on fence posts. They are also active during both the day and night. An owl species common in Montana, which also may be seen on the ground, is the Short-eared Owl. This species, however, is about twice the size of the Burrowing Owl, has dark patches on the wings and at the eyes, short ear tufts, a dark bill, and does not nest is burrows (it nests in a scrape in the ground) (Ehrlich et al. 1988).
Western Hemisphere Range
Observations in Montana Natural Heritage Program Database
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)
Burrowing Owls are migratory in the northern portion of their range, which includes Montana. The extreme dates of observation for Burrowing Owls in this state are, at the earliest, March and, the latest, October (Montana Bird Distribution Committee 2012). The majority of the spring reports for this species occur, however, in April with most fall observations in September.
Some U.S./Canadian breeders winter in Mexico and possibly in Central America (James and Ethier 1989). Canadian breeders are believed to winter south of the U.S.-Mexico border.
Burrowing Owls are found in open grasslands, where abandoned burrows dug by mammals such as ground squirrels (Spermophilus spp.), prairie dogs (Cynomies spp.) and Badgers (Taxidea taxus) are available. Black-tailed Prairie Dog (Cynomys ludoviscianus) and Richardson's Ground Squirrel (Spermophilus richardsonii) colonies provide the primary and secondary habitat for Burrowing Owls in the state (Klute et al. 2003). The burrows may be enlarged or modified, making them more suitable. Burrowing Owls spend much time on the ground or on low perches such as fence posts or dirt mounds.
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
Shrubland, Steppe and Savanna Systems
Sparse and Barren Systems
Wetland and Riparian Systems
- Occasionally Associated with these Ecological Systems
Human Land Use
Recently Disturbed or Modified
Wetland and Riparian Systems
Burrowing Owls are opportunistic feeders; their diet is varied and may depend upon the time of year. Invertebrates comprise the majority of their diet in most areas, but small mammals, amphibians, reptiles, and birds may also be consumed (Haug et al. 1993).
Burrowing Owls have been found using Badger holes in the Bozeman latilong (Skaar 1969). Generally, the reported densities of Burrowing Owls varied from different locations: 8 pairs per square kilometer were found in California; 3.5 to 6 hectares per pair in North Dakota; and 13 to 16 hectares per pair in Saskatchewan.
Territorial defense is mainly limited to the immediate vicinity of nest burrow and individuals may share foraging areas.
Home ranges for Burrowing Owls in Saskatchewan were found to be 0.14 to 4.81 square kilometers; with 95% of all movements within 600 meters of the nest burrow (Haug and Oliphant 1990). Significantly smaller home ranges were reported in Saskatchewan (0.08 to 0.49, average 0.35 square kilometers) during periods of small mammal superabundance (Sissons et al. 1998, Wellicome 1998). Dispersing young use satellite burrows in the vicinity of their natal burrows for about two months after hatching before departing the natal area (King and Belthoff 2001).
The Badger plays an important role in the nesting ecology of Burrowing Owls in northern Oregon. This mammalian species provides nest burrows and can be a major predator of Burrowing Owls (Green and Anthony 1989).
Breeding of Burrowing Owls is well documented in the state. Since this owl species is so tied to prairie dogs and ground squirrels, both species occuring primarily east of the Continental Divide, the majority of confirmed breeding records for Burrowing Owls are also east of the Divide (Klute et al. 2003). The nest chamber, located within a mammal burrow, may be lined with horse dung, cow chips, dry grass, pellets, or feathers; they may occasionally be unlined (Ehrlich et al. 1988). Clutch size averages 6 to 7. The female incubates the elliptical (almost spherical at times), smooth, glossy-white eggs (31x26 mm in size) for 27 to 30 days (Baicich and Harrison 2005). The male provides food during incubation and the early nestling stages. The young owls can run and forage at 4 weeks and can sustain flight at 6 weeks. The average number of fledglings per brood is three to five. This species may first breed at one year of age; generally one brood per year is produced.
No specific management activities directed at the conservation of this species in Montana are documented. Recreational shooting of prairie dogs in their colonies, however, has the potential to cause direct illegal mortality to this owl species (Klute et al. 2003). Systematic suppression of prairie dogs by state agricultural agencies reduces Burrowing Owl habitat, but the overall impact of these activities in combination with recreational shooting has not been studied (Klute et al. 2003).
- Literature Cited AboveLegend: View Online Publication
- 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.
- 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.
- Green, G. A. and R. G. Anthony. 1989. Nesting success and habitat relationships of burrowing owls in the Columbia Basin, Oregon. Condor 91:347-354.
- Haug, E. A. and L. W. Oliphant. 1990. Movements, activity patterns, and habitat use of burrowing owls in Saskatchewan. Journal of Wildlife Management 54:27-35.
- James, P. C. and T. J. Ethier. 1989. Trends in the winter distribution and abundance of burrowing owls in North America. American Birds 43:1224-1225.
- King, R. A. and J. R. Belthoff. 2001. Post-fledging dispersal of burrowing owls in southwestern Idaho: characterization of movements and use of satellite burrows. Condor 103:118-126.
- Klute, D. S., L.W. Ayers, M.T. Green, W.H. Howe, S.L. Jones, J.A. Shaffer, S.R. Sheffield, and T.S. Zimmerman. 2003. Status assessment and conservation plan for western burrowing owl the in the United States. U.S. Department of the Interior; Fish and Wildlife Service, Biological Technical Publication FWS/BTP-R6001-2003, Washington, D.C.
- 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.
- Sibley, D.A. 2000. The Sibley guide to birds. National Audubon Society and Alfred A. Knopf, Inc., New York, NY. 544 pp.
- Sissons, R., K. Skalise, and T. Wellicome. 1998. Nocturnal foraging habitat use of the burrowing owl in a heavily cultivated region of southern Saskatchewan. Abstracts of the Second International Burrowing Owl Symposium, September 1998, Ogden, UT.
- 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.
- Wellicome, T.I. 1998. Can we manage reproductive output in burrowing owls by managing their prey? Second International Burrowing Owl Symposium, September 29-30, 1998, Ogden, Utah. Canadian Wildlife Service and Environment Canada.
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?
- [PRESI] Powder River Eagle Studies Incorporated. 1998b. Spring Creek Mine 1997 wildlife monitoring studies. Powder River Eagle Studies Incorporated. Gillete, WY.
- Abstracts from Montana Rare Animal Meeting. 1992. [November 5-6, 1992]. Lewistown, MT. 20 pp.
- 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.
- American Ornithologists Union. 1983. Checklist of North American birds, 6th Edition. 877 PP.
- American Ornithologists’ Union [AOU]. 1997. Forty-first supplement to the American Ornithologists’ Union Check-list of North American birds. Auk 114(3):542-552.
- American Ornithologists’ Union [AOU]. 1998. Check-list of North American birds, 7th edition. American Ornithologists’ Union, Washington, D.C. 829 p.
- Becker, Dale M., 1980, A Survey of raptors on national forest land in Carter County, Montana. Final Progress Report: 1977-1979.
- Bird Conservancy of the Rockies. 2017. Pocket Guide to Northern Prairie Birds. Brighton, CO: Bird Conservancy of the Rockies. 98 p.
- Burton, J.A. 1973. Owls of the world: their evolution, structure and ecology. 1st ed., E.P. Dutton & Co., Inc., New York, NY.
- Casey, D. 2000. Partners in Flight Draft Bird Conservation Plan Montana. Version 1.0. 287 pp.
- Cavanagh, P. M. 1990. Above-ground nesting by burrowing owls. J. Raptor Res. 24:68-69.
- Cooper, S.V., C. Jean, and P. Hendricks. 2001. Biological survey of a prairie landscape in Montana's glaciated plains. Report to the Bureau of Land Management. Montana Natural Heritage Program, Helena, MT. 24 pp. plus appendices.
- Decker Coal Co., 1981, Wildlife survey. July 7, 1981. In North Decker 5-Year Permit Application. Vol. III. Rule 26.4.304(12-14).
- 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.
- Drost, C.A., and R.C. McCluskey. 1992. Extirpation of alternative prey during a small rodent crash. Oecologia 92:301-304.
- Dundas, H., and J. Jensen. 1994/95. Burrowing owl status and conservation. Bird Trends (Canadian Wildlife Service) (4):21-22.
- 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.
- Econ, Inc., Helena, MT., 1991, Wildlife monitoring report: 1989 field season, Big Sky Mine. March 1991.
- Gillihan, SW. and T. VerCauteren. 2015. Pocket Guide to Prairie Birds. Brighton, CO: Bird Conservancy of the Rockies. 91 p.
- Gniadek, S. 1983. Southwest Glendive Wildlife Baseline Inventory. Miles City, Mont: Bureau of Land Management, Miles City District Office. 56 pp with appendices.
- Goodell, J. 2012. Morse Land Company Breeding Bird Inventory And Analysis. High Desert Museum. Bend, OR. 42 pp + Appendices.
- Hand, R. L. 1969. A distributional checklist of the birds of western Montana. Unpublished. Available at Mansfield Library, University of Montana, Missoula.
- Haug, E.A., and A.B. Didiuk. 1991. Updated Status Report on the Burrowing Owl Athene cunicularia hyugaea in Canada. Committee On the Status of Endangered Wildlife in Canada (COSEWIC). 29 pp.
- Haug, E.A., B.A. Millsap, and M.S. Martell. 1993. Burrowing Owl (Athene cunicularia). Species Account Number 061. The Birds of North America Online (A. Poole, Ed.). Ithaca, NY: Cornell Laboratory of Ornithology.
- Jellison, W. L. 1940. The burrowing owl as a host to the argasid tick, Ornithodoros parkeri. Public Health Reps. 55:206-208.
- 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.
- Kantrud, H. A. 1981. Grazing intensity effects on the breeding avifauna of North Dakota native grasslands. Can. Field-Nat. 95:404-417.
- Kantrud, H. A., and R. L. Kologiski. 1982. Effects of soils and grazing on breeding birds of uncultivated upland grasslands in the northern Great Plains. Wildlife Research Report No. 15, U.S. Fish and Wildlife Service, Washington, D.C.
- Knowles, C. J. and P. R. Knowles. 1995. A survey of biological resources at the proposed Malta, MT airport site. Unpublished report. FaunaWest Wildlife Consultants, Boulder, MT. 6 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.
- 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.
- Matthews, W.L. 1981. Broadus-Pumpkin Creek baseline inventory - wildlife. Bureau of Land Management, Miles City, MT. 83 p.
- 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.
- Pitkin, P. and L. Quattrini. 2017. Pocket Guide to Sagebrush Birds. Bird Conservancy of the Rockies and Point Blue Conservation Science. 68 p.
- Plumpton, D.L. 1992. Aspects of nest site selection and habitat use by Burrowing Owls at the Rocky Mountain Arsenal, Colorado. M.S. thesis, Texas Tech. Univ., Lubbock.
- 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., 1997, Spring Creek Mine 1996 Wildlife Monitoring Studies. February 1997.
- Powder River Eagle Studies, Inc., Gillette, WY., 1999, Spring Creek Mine 1998 Wildlife Monitoring. March 1999.
- Powder River Eagle Studies, Inc., Gillette, WY., 2000, Spring Creek Mine 1999 Wildlife Monitoring. March 2000.
- Rogers, Ralph. 1996. Interim Report: Burrowing owls inhabiting prairie dog towns on BLM lands in north central Montana.
- 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, 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.
- South Dakota Ornithologists' Union. 1991. The birds of South Dakota. Second Edition. Northern State University Press, Aberdeen, South Dakota. 411 pp.
- Thompson, L.S. 1981. Circle West wildlife monitoring study: Third annual report. Technical report No. 8. Montana Department of Natural Resources and Conservation. Helena, Montana.
- Thompson, L.S. 1982. Circle West Wildlife Monitoring Study. Fourth annual report. Technical report 10. Montana Department of Natural Resources and Conservation, Helena, Montana.
- 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.
- Waage, B.C. 1989. Western Energy Company Rosebud Mine, Colstrip, Montana: Annual Wildlife Monitoring Report, 1989 Field Season. December 1989.
- 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.
- Wedgwood, J. A. 1979. Status Report on the Burrowing Owl, Athene cunicularia, in Canada. Committee on the Status of Endangered Wildlife in Canada. 90 pp.
- Wellicome, T.I., and E.A. Haug. 1995. Second update of status report on the burrowing owl (Speotyto cunicularia) in Canada. Committee on the Status of Endangered Wildlife in Canada, Canadian Wildlife Service, Environment Canada, Ottawa, Ontario. 32 pp.
- 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 Technology and Engineering, Inc. (WESTECH)., 1989, Wildlife Monitoring: Absaloka Mine Area Annual Report, 1989. 12/21/88-12/20/89. Montana SMP 85005 R1. OSMP Montana 0007B. Febr. 15, 1990.
- Wiley, J.W. 1998. Breeding-season food habits of burrowing owls (Athene cunicularia) in southwestern Dominican Republic. J. Raptor Res. 32(3): 241-245
- Zelenak, J. R. 1996. Breeding ecology of Ferruginous Hawks at the Kevin Rim in northern Montana. M.S. thesis, Montana State University, Bozeman.
- Additional Sources of Information Related to "Birds"