Gadwall - Mareca strepera
Species sexually dimorphic. Males in alternate plummage have gray brown body with a white abdomen and black rump. Black and chestnut portions of some inner median and lesser wing-coverts, slate gray bill, and yellow legs. Females overall brownish color with distinctive bill color (orange yellow with dark longitudinal midsection and gray black lateral spots), and presence of white speculum.
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.
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)
Normal migration periods in the Bozeman area are from March 20 to May 20 and from October 1 to November 10, with peak numbers reached on April 20 and October 15 (Skaar 1969).
At Bowdoin National Wildlife Refugem, Gadwall nest density was highest in saline lowlands, followed by dense nesting cover, panspots, and silty/ shallow clay. Nest success was highest in saline lowlands, then clay, panspots, silty sites and dense cover (Holm 1984).
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
Human Land Use
Recently Disturbed or Modified
Wetland and Riparian Systems
- Occasionally Associated with these Ecological Systems
Wetland and Riparian Systems
Diet consists mainly of submerged aquatic vegitation, seeds and aquatic invertebrates.
The primary cause of nest loss was depradation (67%) from (in order of importance): Striped Skunk, Red Fox, Coyote, Richardson's Ground Squirrel, Raccoon, avian, and American Mink. At Freezeout Lake, Striped Skunks were the major cause of unsuccessful nests.
The brood size was 6.2 in rest-rotation grazing pastures in north-central Montana. Nesting occurred from late May to the third week of August. At Freezeout Lake, island nesters were most successful (75%). The average of all types was 28%. The average clutch size was 11.9 and hatching dates were from May 21 to August 10.
- Literature Cited AboveLegend: View Online Publication
- Holm, I. 1984. Hatching success of upland nesting ducks in north central Montana in relation to vegetation cover. 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?
- [WWPC] Washington Water Power Company. 1995. 1994 wildlife report Noxon Rapids and Cabinet Gorge Reservoirs. Washington Water Power Company. Spokane, WA.
- American Ornithologists’ Union [AOU]. 1998. Check-list of North American birds, 7th edition. American Ornithologists’ Union, Washington, D.C. 829 p.
- Banks, R.C. and P.F. Springer. 1994. A century of population trends of waterfowl in western North America. Studies in Avian Biology, No. 15: 134-146.
- Belanger, L. 1988. Use of man-made ponds by dabbling duck broods. J. Wildl. Manage. 52(4): 718-723.
- Bird Conservancy of the Rockies. 2017. Pocket Guide to Northern Prairie Birds. Brighton, CO: Bird Conservancy of the Rockies. 98 p.
- Bramblett, R.G., and A.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.
- Confluence Consulting Inc. 2011. Montana Department of Transportation Wetland Mitigation Monitoring Reports (various sites). MDT Helena, MT.
- Confluence Consulting Inc. 2013. Montana Department of Transportation Wetland Mitigation Monitoring Reports (various sites). MDT Helena, MT.
- Crabtree, R.L., L.S. Broome and M.L. Wolfe. 1989. Effects of habitat characteristics on Gadwall nest predation and nest site selection. J. Wildl. Manage. 53(1): 129-137.
- Decker Coal Company., 1979?, West Decker 5 Year Permit: Avian research and mitigation. In Decker Coal Company West Pit Permit. Vol. 3. 26.4.304(10-11), 305, 306, and 307. Updated Rules Rewrite, July 1, 1991.
- Duebbert, H.F., J.T. Lokemoen, and D.E. Sharp. 1983. Concentrated nesting of Mallards and Gadwalls on Miller Lake Island, North Dakota. J. Wildl. Manage. 47(5): 729-740.
- ECON, Inc. (Ecological Consulting Service), Helena, MT., 1975, Colstrip 10 x 20 Area wildlife and wildlife habitat annual monitoring report, 1975. Proj. 71-23-A. December 31, 1975.
- ECON, Inc. (Ecological Consulting Service), Helena, MT., 1976, Colstrip 10 x 20 Area wildlife and wildlife habitat annual monitoring report, 1976. Proj. 135-85-A. December 31, 1976.
- 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.
- ECON, Inc. (Ecological Consulting Service), Helena, MT., 1979, Area B four-section wildlife report. August 3, 1979.
- Econ, Inc. 1988. Wildlife monitoring report, 1987 field season, Big Sky Mine. March 1988. In Peabody Mining and Reclamation Plan Big Sky Mine Area B. Vol. 8, cont., Tab 10 - Wildlife Resources. Appendix 10-1, 1987 Annual Wildlife Report.
- Econ, Inc., Helena, MT., 1978, Peabody Coal Company Big Sky Mine, Rosebud County, MT. Wildlife and wildlife habitat monitoring study. Proj. 190-85-A. December 31, 1978.
- Econ, Inc., Helena, MT., 1989, Wildlife monitoring report, 1988 field season, Big Sky Mine. March 1989.
- 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.
- 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.
- Johnsgard, P.A. 1975. Waterfowl of North America. Indiana University Press, Bloomington.
- Johnsgard, P.A. 1979. Birds of the Great Plains: breeding species and their distribution. University of Nebraska Press, Lincoln. 539 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, D.H. and J.W. Grier. 1988. Determinants of breeding and distributions of ducks. Wildl. Monogr. 100: 1-37.
- Klett, A.T., T.L. Shaiffer, and D.H. Johnson. 1988. Duck nest success in the Prairie Pothole Region. J. Wildl. Manage. 52(3): 431-440.
- Lambing, J. H., D. A. Nimick, J. R. Knapton, and D. U. Palawski. 1994. Physical, chemical, and biological data for detailed study of the Sun River Irrigation Project, Freezout Lake Wildlife Management Area, and Benton Lake National Wildlife Refuge, west-central Montana, 1990-92, with selected data for 1987-89. Open-File Report 94-120, U.S. Geological Survey, Helena, Montana.
- Land & Water Consulting, Inc., Missoula, MT., 2002, Montana Dept. of Transportation Wetland Mitigation Monitoring Report, Year 2001: Beaverhead Gateway, Dillon, Montana. Proj. No. 130091.011. July 2002. In 2001 Wetland Mitigation Monitoring Reports, Vol. I.
- Land & Water Consulting, Inc., Missoula, MT., 2002, Montana Dept. of Transportation Wetland Mitigation Monitoring Report, Year 2001: Johnson - Valier, Valier, Montana. Proj. No. 130091.018. July 2002. In 2001 Wetland Mitigation Monitoring Reports, Vol. I.
- Land & Water Consulting, Inc., Missoula, MT., 2002, Montana Dept. of Transportation Wetland Mitigation Monitoring Report, Year 2001: Musgrave Lake, Montana. Proj. No. 130091.019. July 2002. In 2001 Wetland Mitigation Monitoring Reports, Vol. II.
- Land & Water Consulting, Inc., Missoula, MT., 2002, Montana Dept. of Transportation Wetland Mitigation Monitoring Report, Year 2002: Fourchette Creek Reservoir Complex, Phillips County, Montana. Proj. No. 130091.023. February 2003. In 2002 Wetland Mitigation Monitoring Reports, Vol. I.
- Land & Water Consulting, Inc., Missoula, MT., 2002, Montana Dept. of Transportation Wetland Mitigation Monitoring Report, Year 2002: Musgrave Lake, Zurich, Montana. Proj. No. 130091.019. May 2003. In 2002 Wetland Mitigation Monitoring Reports, Vol. II.
- Lenard, S. and P. Hendricks. 2005. Birds of selected grassland and riparian plots along the Rocky Mountain Front. Montana Natural Heritage Program for US Fish and Wildlife Service and The Nature Conservancy. 17pp + maps.
- 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.
- LeSchack, C. R., S. K. McKnight, and G. R. Hepp. 1997. Gadwall (Anas strepera). In The birds of North America, No. 283 (A. Poole and F. Gill, Eds.). Academy of Natural Sciences of Philadelphia and American Ornithologists’ Union.
- Lokemoen, J.T., H.F. Duebbert, and D.E. Sharp. 1990. Homing and reproductive habits of Mallards, Gadwalls, and Blue-winged Teal. Wildl. Monogr. 106:1-28.
- Mack, G.D. and L.D. Flake. 1980. Habitat relationships of waterfowl broods on South Dakota stock ponds. J. Wildl. Manage. 44(3): 695-700.
- Matthews, W.L. 1981. Broadus-Pumpkin Creek baseline inventory - wildlife. Bureau of Land Management, Miles City, MT. 83 p.
- Montana Bird Distribution Committee. 2012. P.D. Skaar's Montana bird distribution. 7th Edition. Montana Audubon, Helena, Montana. 208 pp. + foldout map.
- Palawski, D.U., et al., 1991, Contaminant biomonitoring at the Benton Lake National Wildlife Refuge in 1988.
- Palmer, R.S. 1962. Handbook of North American birds. Volume 1. Loons through flamingos. Yale University Press, New Haven. 567 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.
- Stewart, R. E., and H. A. Kantrud. 1973. Ecological distribution of breeding waterfowl populations in North Dakota. Journal of Wildlife Management 37(1):39-50.
- Stewart, R.E. and H.A. Kantrud. 1974. Breeding waterfowl populations in the Prairie Pothole Region of North Dakota. Condor 76: 70-79.
- TRC Environmental Corporation. 2009. Results of the 2008 grassland bird displacement study at the Judith Gap wind energy project, Wheatland County, Montana. Judith Gap Energy LLC. Chicago, IL. 24 pp + appendices.
- 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.
- 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 Technology and Engineering, Inc. (WESTECH)., 2000, Wildlife Monitoring Absaloka Mine Area Annual Report, 1999. Montana SMP 85005. OSMP Montana 0007E. February 2000.
- Additional Sources of Information Related to "Birds"