Lesser Scaup - Aythya affinis
A medium-sized (41.9 to 43 cm, 730 to 850 g) black and white diving duck, one of the most abundant and widespread of North American ducks. Adults sexually dimorphic most of year. Male in Definitive Alternate plumage characterized by slaty blue bill; black head with purplish gloss; black neck, breast, and upper mantle; white flanks and belly; gray-flecked lower mantle; and black vent and undertail region. Female is fuscous to chocolate brown with white patch of varying size at base of bill (sometime broken into patches of white); upperparts darker; wing-coverts flecked with gray; bill dark gray. Iris color in males is brilliant yellow, but in females varies with age from olive brown to olive or brownish yellow (Austin 1998).
Western Hemisphere Range
Summary of Observations Submitted for Montana
Number of Observations:
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Map Help and Descriptions
(direct evidence "B")
(indirect evidence "b")
No evidence of Breeding
(regular observations "W")
(at least one obs. "w")
(Observations spanning multiple months or years are excluded from time charts)
Normal migration periods in the Bozeman area are April 10 to May 25 and October 1 to November 20, with peak numbers on April 25 and October 25 (Skaar 1969).
In the Bozeman area, habitat is generally restricted to lakes and ponds (Skaar 1969). Throughout fall and winter this species forms large flocks on rivers, lakes, and large wetlands. Pairs and broods typically associated with fresh to moderately brackish, seasonal and semipermanent wetlands and lakes with emergent vegetation such as bulrush, cattail and river bulrush (Austin et al. 1998).
Ecological Systems Associated with this Species
- Details on Creation and Suggested Uses and Limitations
How Associations Were Made
We associated the use and habitat quality (high, medium, or low) of each of the 82 ecological systems mapped in Montana for
vertebrate animal species that regularly breed, overwinter, or migrate through the state by:
- Using personal observations and reviewing literature that summarize the breeding, overwintering, or migratory habitat requirements of each species (Dobkin 1992, Hart et al. 1998, Hutto and Young 1999, Maxell 2000, Foresman 2001, Adams 2003, and Werner et al. 2004);
- Evaluating structural characteristics and distribution of each ecological system relative to the species’ range and habitat requirements;
- Examining the observation records for each species in the state-wide point database associated with each ecological system;
- Calculating the percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system to get a measure of “observations versus availability of habitat”.
Species that breed in Montana were only evaluated for breeding habitat use, species that only overwinter in Montana were only evaluated for overwintering habitat use, and species that only migrate through Montana were only evaluated for migratory habitat use.
In general, species were associated as using an ecological system if structural characteristics of used habitat documented in the literature were present in the ecological system or large numbers of point observations were associated with the ecological system.
However, species were not associated with an ecological system if there was no support in the literature for use of structural characteristics in an ecological system, even if
point observations were associated with that system.
High, medium, and low habitat quality was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species in the literature.
The percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system was also used to guide assignments of habitat quality.
If you have any questions or comments on species associations with ecological systems, please contact Bryce Maxell at email@example.com
or (406) 444-3655.
Suggested Uses and Limitations
Species associations with ecological systems should be used to generate potential lists of species that may occupy broader landscapes for the purposes of landscape-level planning.
These potential lists of species should not be used in place of documented occurrences of species (this information can be requested at: http://mtnhp.org/requests/default.asp
) or systematic surveys for species and evaluations of habitat at a local site level by trained biologists.
Users of this information should be aware that the land cover data used to generate species associations is based on imagery from the late 1990s and early 2000s and was only intended to be used at broader landscape scales.
Land cover mapping accuracy is particularly problematic when the systems occur as small patches or where the land cover types have been altered over the past decade.
Thus, particular caution should be used when using the associations in assessments of smaller areas (e.g., evaluations of public land survey sections).
Finally, although a species may be associated with a particular ecological system within its known geographic range, portions of that ecological system may occur outside of the species’ known geographic range.
- Adams, R.A. 2003. Bats of the Rocky Mountain West; natural history, ecology, and conservation. Boulder, CO: University Press of Colorado. 289 p.
- Dobkin, D. S. 1992. Neotropical migrant land birds in the Northern Rockies and Great Plains. USDA Forest Service, Northern Region. Publication No. R1-93-34. Missoula, MT.
- Foresman, K.R. 2001. The wild mammals of Montana. Special Publication No. 12. Lawrence, KS: The American Society of Mammalogists. 278 p.
- Hart, M.M., W.A. Williams, P.C. Thornton, K.P. McLaughlin, C.M. Tobalske, B.A. Maxell, D.P. Hendricks, C.R. Peterson, and R.L. Redmond. 1998. Montana atlas of terrestrial vertebrates. Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT. 1302 p.
- Hutto, R.L. and J.S. Young. 1999. Habitat relationships of landbirds in the Northern Region, USDA Forest Service, Rocky Mountain Research Station RMRS-GTR-32. 72 p.
- Maxell, B.A. 2000. Management of Montana’s amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species. Report to U.S. Forest Service Region 1. Missoula, MT: Wildlife Biology Program, University of Montana. 161 p.
- Werner, J.K., B.A. Maxell, P. Hendricks, and D. Flath. 2004. Amphibians and reptiles of Montana. Missoula, MT: Mountain Press Publishing Company. 262 p.
- Commonly Associated with these Ecological Systems
Wetland and Riparian Systems
- Occasionally Associated with these Ecological Systems
Forest and Woodland Systems
Shrubland, Steppe and Savanna Systems
Mainly aquatic invertebrates such as insects, crustaceans, and mollusks. Seeds and vegetative parts of aquatic plants are important in certain areas (Austin et al. 1998).
At Bowdoin National Wildlife Refige, 25,000 were seen in November 1949. The major cause of unsuccessful nests at Freezeout Lake was skunk predation.
Individuals form new pair bonds during spring migration each year. Female builds nest on the ground near or over water, as well as in uplands, unlike other diving ducks. Eggs are elliptical to nearly oval in shape. The color is pale olive or greenish buff to dark olive buff. Most clutches have 8 to 10 eggs (Austin et al. 1998). Actual nest records are scattered from mid-May to August 10. Hatching dates at Freezeout Lake were from June 1 to August 20. Birds nesting on islands were more successful (60%) than those in other habitat types (average of all was 23.5%). Average clutch size was 9.5.
- Additional ReferencesLegend: View WorldCat Record View Online Publication
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- American Ornithologists' Union. 1998. Check-list of North American birds. 7th edition. American Ornithologists' Union, Washington, D.C. 829 pp.
- Austin, Jane E., Christine M. Custer, and Alan D. Afton. 1998. Lesser Scaup (Aythya affinis). Species Account Number 338. 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
- 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.
- 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.
- Golden Sunlight Mines, Inc., Whitehall, MT., 2000, Golden Sunlight Mines, Inc., Annual Permit Reports.
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- 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.
- Lambing, John H., et al., 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. May 1994. Open-file report 94-120.
- 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.
- 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.
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- Powder River Eagle Studies, Inc., Gillette, WY., 2000, Spring Creek Mine 2000 Wildlife Monitoring. March 2000.
- Sibley, D. 2014. The Sibley guide to birds. Alfred A. Knopf, New York, NY. 598 pp.
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- The Anaconda Co., 1976, Wildlife survey: The Anaconda Company Berkeley Complex 1976 Proposed Permit Area. May 6, 1976.
- 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.
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- 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., 1996, Western Energy Company Rosebud Mine, Colstrip, Montana: 1995 Annual Wildlife Monitoring Report; December 1, 1994 - November 30, 1995. February 28, 1996.
- 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., 2001, Western Energy Company Rosebud Mine, Colstrip, Montana: 2000 Annual Wildlife Monitoring Report; December 1, 1999 - November 30, 2000. March 30, 2001.
- 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.
- 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)., 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.