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Lesser Scaup - Aythya affinis
General Description
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 et al. 1998).
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.Species Range
Montana Range
Range Descriptions
Western Hemisphere Range
Observations in Montana Natural Heritage Program Database
Number of Observations: 8195
(Click on the following maps and charts to see full sized version)
Map Help and Descriptions
Relative Density
Recency
SUMMER (Feb 16 - Dec 14)
Direct Evidence of Breeding
Indirect Evidence of Breeding
No Evidence of Breeding
WINTER (Dec 15 - Feb 15)
Regularly Observed
Not Regularly Observed
(Observations spanning multiple months or years are excluded from time charts)
Migration
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).
Habitat
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 (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:
mtnhp.org/requests) 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.
Literature Cited
- 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
Grassland Systems
Recently Disturbed or Modified
Wetland and Riparian Systems
- Occasionally Associated with these Ecological Systems
Forest and Woodland Systems
Grassland Systems
Human Land Use
Shrubland, Steppe and Savanna Systems
Food Habits
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).
Ecology
At Bowdoin National Wildlife Refige, 25,000 were seen in November 1949. The major cause of unsuccessful nests at Freezeout Lake was skunk predation.
Reproductive Characteristics
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.
Stewardship Responsibility
References
- Literature Cited AboveLegend:
View Online Publication
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- 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.
- Bayless, S.R. 1992. Duck population responses to water development in north central Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 69 p.
- Bramblett, R.G., and A.V. Zale. 2002. Montana Prairie Riparian Native Species Report. Montana Cooperative Fishery Research Unit, Montana State University - Bozeman.
- Butler, M.A. 1996. The validity of using artificial nests to assess nest-predation rates in prairie nesting ducks. M.Sc. Thesis. Bozeman, MT: Montana State University. 82 p.
- Cameron, E. S. 1907. The birds of Custer and Dawson counties, Montana. Auk 24(3): 241-270.
- Cornely, J.E. 1982. Waterfowl production at Malheur National Wildlife Refuge, 1942-1980. Transactions of the 47th North American Wildlife and Natural Resources Conference. pp 559-571.
- Cutting, K.A. 2010. Nutrient allocation to egg formation of Lesser Scaup. M.Sc. Thesis. Bozeman, Montana: Montana State University. 74 p.
- Deane, C.E. 2017. Harvest, nasal-markers, and Lesser Scaup vital rates. M.Sc. Thesis. Bozeman, MT: Montana State University. 102 p.
- Dickson, D.C. 1991. Systematic wildlife observations on the Blackfoot-Clearwater Wildlife Management Area. Montana Department of Fish, Wildlife and Parks. Missoula, MT. 14 pp. plus appendices and photographs.
- 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.
- Ellig, L.J. 1953. Waterfowl relationships to Greenfields Lake, Teton County, Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 49 p.
- Gjersing, F.M. 1971. A study of waterfowl production on two rest rotation grazing units in northcentral Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 42 p.
- Gjersing, F.M. 1975. Waterfowl production in relation to rest-rotation grazing. Journal of Range Management 28:37-42.
- Gniadek, S. 1983. Southwest Glendive Wildlife Baseline Inventory. Miles City, Mont: Bureau of Land Management, Miles City District Office. 56 pp with appendices.
- Golden Sunlight Mines, Inc. 2000. Golden Sunlight Mines, Inc., Whitehall, MT. Annual Permit Reports.
- Goodell, J. 2012. Morse Land Company Breeding Bird Inventory And Analysis. High Desert Museum. Bend, OR. 42 pp + Appendices.
- Hays, R., R.L. Eng, and C.V. Davis (preparers). 1984. A list of Montana birds. Helena, MT: MT Dept. of Fish, Wildlife & Parks.
- Hendricks, P, S. Lenard, and C. Currier. 2012. Grassland Bird Surveys in North Valley County and Northwest Phillips County, Montana: 2011 Summary. Report to the USDI Bureau of Land Management. Montana Natural Heritage Program. Helena, MT. 7pp.
- Hendricks, P. and C.J. Norment. 1986. Additions to the alpine avifauna of the Beartooth Mountains. The Murrelet 67:90-92.
- Hendricks, P., S. Lenard, C. Currier, B. A. Maxell, and J. Carlson. 2008. Surveys for grassland birds of the Malta Field Office-BLM, including a seven-year study in north Valley County. Montana Natural Heritage Program, Helena.
- Hildebrand, B. D. 1979. Habitat requirements of molting Canada Geese at Lima Reservoir, Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 79 p.
- Hudson, M.S. 1980. Waterfowl production on three age-classes of stock ponds in north central Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 45 p.
- Johnsgard, P.A. 1975. Waterfowl of North America. Bloomington, IN: Indiana University Press. 575 p.
- 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, K.M. 1990. Aquatic vegetation, salinity, aquatic invertebrates, and duck brood use at Bowdoin National Wildlife Refuge, Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 77 p.
- Joslin, Gayle, and Heidi B. Youmans. 1999. Effects of recreation on Rocky Mountain wildlife: a review for Montana. [Montana]: Montana Chapter of the Wildlife Society.
- Knight, R.R. 1960. Vegetative characteristics of two water areas in Teton County, Montana, in relation to waterfowl usage. M.Sc. Thesis. Bozeman, MT: Montana State University. 38 p.
- Knight, R.R. 1965. Vegetative characteristics and waterfowl usage of a Montana water area. J. Wildl. Manage. 29(4):782-788.
- Korschgen, C.E., and R.B. Dahlgren. 1992. Human disturbances of waterfowl: causes, effects, and management. Ch. 13.2.15 In: Waterfowl Management Handbook. Fish and Wildlife Service Leaflet. 8 p.
- 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.
- Lenard, S. 2006. Birds of Blaine County, Riparian Point Count Surveys 2005. Report to the Bureau of LandManagement, Havre Field Station, Havre, Montana. Montana Natural Heritage Program, Helena, MT. 16pp.plus appendices.
- 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.
- Lokemoen, J.T. 1966. Breeding ecology of the redhead duck in western Montana. Journal of Wildlife Management 30(4):668-681.
- Lokemoen, J.T. 1993. Increasing waterfowl nesting success on islands and peninsulas. Ch. 13.2.11 In: Waterfowl Management Handbook. Fish and Wildlife Service Leaflet. 7 p.
- Lokemoen, J.T., and R.O. Woodward. 1992. Nesting waterfowl and water birds on natural islands in the Dakotas and Montana. Wildlife Society Bulletin 20:163-171.
- Lorang, K.D. 1979. Waterfowl and hunter use of Freezeout Lake Game Management Area. M.Sc. Thesis. Bozeman, Montana: Montana State University. 79 p.
- Matthews, W.L. 1981. Broadus-Pumpkin Creek baseline inventory - wildlife. Bureau of Land Management, Miles City, MT. 83 p.
- McCarthy, J.J. 1973. Response of nesting Canada geese (Branta canadensis) to islands in stockdams in northcentral Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 36 p.
- Miller, M.G. 1980. The influence of habitat features on waterfowl productivity on stock reservoirs in south Valley County, Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 43 p.
- Montana Bird Distribution Committee. 2012. P.D. Skaar's Montana bird distribution. 7th Edition. Montana Audubon, Helena, Montana. 208 pp. + foldout map.
- MT Fish, Wildlife & Parks. No date. Blackfoot-Clearwater Wildlife Management Area checklist.
- Mundinger, J.G. 1975. The influence of rest-rotation grazing management on waterfowl production on stock-water reservoirs in Phillips County, Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 100 p.
- Oechsli, L.M. 2000. Ex-urban development in the Rocky Mountain West: consequences for native vegetation, wildlife diversity, and land-use planning in Big Sky, Montana. M.Sc. Thesis. Montana State University, Bozeman. 73 p.
- Palawski, D.U., et al., 1991, Contaminant biomonitoring at the Benton Lake National Wildlife Refuge in 1988.
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