Index of Species Information

WILDLIFE SPECIES:  Anas strepera


AUTHORSHIP AND CITATION : Tesky, Julie L. 1993. Anas strepera. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: [].

ABBREVIATION : ANST COMMON NAMES : gadwall gray (grey) duck gray mallard gray widgeon redwing TAXONOMY : The currently accepted scientific name for the gadwall is Anas strepera Linnaeus. There are no recognized subspecies [1,6]. ORDER : Anseraformes CLASS : Bird FEDERAL LEGAL STATUS : No special status OTHER STATUS : NO-ENTRY


GENERAL DISTRIBUTION : In North America the gadwall's breeding range extends from southern Alaska and southern Yukon to the New Brunswick-Nova Scotia border, south locally to southern California, northern Texas, central Minnesota, and northern Pennsylvania, and along the Atlantic Coast south to Florida and the Gulf Coast [6,19].  It also breeds in Iceland, the British Isles, Europe, and Asia [6]. In North America the gadwall winters from coastal Alaska south to southern Mexico, the Gulf Coast, and along the Atlantic Coast to southern New England [6,19]. ECOSYSTEMS : FRES14 Oak-pine FRES15 Oak-hickory FRES17 Elm-ash-cottonwood FRES18 Maple-beech-birch FRES19 Aspen-birch FRES36 Mountain grasslands FRES37 Mountain meadows FRES38 Plains grasslands FRES39 Prairie FRES41 Wet grasslands FRES42 Annual grasslands STATES :


BLM PHYSIOGRAPHIC REGIONS :     1  Northern Pacific Border     2  Cascade Mountains     3  Southern Pacific Border     4  Sierra Mountains     5  Columbia Plateau     6  Upper Basin and Range     7  Lower Basin and Range     8  Northern Rocky Mountains     9  Middle Rocky Mountains    10  Wyoming Basin    11  Southern Rocky Mountains    12  Colorado Plateau    13  Rocky Mountain Piedmont    14  Great Plains    15  Black Hills Uplift    16  Upper Missouri Basin and Broken Lands KUCHLER PLANT ASSOCIATIONS :    K047  Fescue - oatgrass    K048  California steppe    K049  Tule marshes    K050  Fescue - wheatgrass    K051  Wheatgrass - bluegrass    K053  Grama - galleta steppe    K054  Grama - tobosa prairie    K056  Wheatgrass - needlegrass shrubsteppe    K057  Galleta - three-awn shrubsteppe    K058  Grama - tobosa shrubsteppe    K063  Foothills prairie    K064  Grama - needlegrass - wheatgrass    K065  Grama - buffalograss    K066  Wheatgrass - needlegrass    K067  Wheatgrass - bluestem - needlegrass    K068  Wheatgrass - grama - buffalograss    K069  Bluestem - grama prairie    K072  Sea oats prairie    K073  Northern cordgrass prairie    K074  Bluestem prairie    K075  Nebraska Sandhills prairie    K076  Blackland prairie    K077  Bluestem - sacahuista prairie    K078  Southern cordgrass prairie    K079  Palmetto prairie    K094  Conifer bog    K098  Northern floodplain forest    K100  Oak - hickory forest SAF COVER TYPES :     16  Aspen     17  Pin cherry     18  Paper birch     63  Cottonwood     88  Willow oak - water oak - diamondleaf oak     89  Live oak     95  Black willow    203  Balsam poplar    217  Aspen    235  Cottonwood - willow    252  Paper birch SRM (RANGELAND) COVER TYPES : NO-ENTRY PLANT COMMUNITIES : During the breeding season, gadwalls often inhabit islands in wetland communities with patches of dense western snowberry (Symphoricarpos occidentalis), slim nettle (Urtica gracilis), Canada thistle (Cirsium arvense), rose (Rosa spp.), and brome (Bromus spp.).  Additionally, gadwalls commonly use areas dominated by cattail (Typha spp.), bulrush (Scirpus spp.), sedge (Carex spp.), and common rivergrass (Scolochloa festucacea) [8].  Gadwalls will also use upland cover types of cropland, pasture and hayland, grassland, and mixed prairie and weed [8,9,16]. REFERENCES : NO-ENTRY


TIMING OF MAJOR LIFE HISTORY EVENTS : Breeding and nesting - The gadwall's breeding season varies but usually occurs in May through mid-July, somewhat later in the northern regions and earlier in the south [2,11]. Clutch/incubation - Gadwalls lay 5 to 13 eggs per nest, and incubation is 24 to 28 days [1,13]. Fledge - Gadwalls fledge 7 to 8 weeks after hatching [6]. Maturity - Gadwalls become sexually mature and acquire their breeding plummage during their first winter [6]. Migration - Gadwalls are one of the last ducks to arrive on breeding areas in the spring [1]. Some early dates of arrival for various areas in North America are as follows [2]:                 Southern Iowa - March 10                 Minnesota, Heron Lake - March 17                 Montana - April 1                 Manitoba - April 23                 Saskatchewan - April 18                 Alberta - May 5 PREFERRED HABITAT : Gadwall pairs use wetlands for feeding, loafing, and courtship prior to nesting [16].  They prefer prairie marshes, sloughs, ponds, or small lakes in grasslands of both freshwater and brackish habitats.  They generally avoid wetlands bordered by woodlands or thick brush, preferring those bordered by dense, low herbaceous vegetation, or with grassy islands [6,17,19].  Shallow semipermanent prairie marshes are preferred over deeper marshes, lakes or temporary water areas [6,16]. Sixy one percent of 1,073 gadwall broods observed over a 20-year period in North and South Dakota were in semipermanent wetlands [16]. Winter habitat - Gadwalls prefer to winter in freshwater, marshy habitats and slightly brackish estuarine bays [6,19]. Nesting - Gadwalls nest on well-drained sites on islands in lakes, upland meadows or pastures, alfalfa fields, or on prairies usually within 150 feet (45 m) of water.  They prefer to nest in uplands rather than over water [19] and generally select the tallest, densest, herbaceous or shrubby vegetation available to nest in [16]. COVER REQUIREMENTS : For escape cover, gadwalls prefer large areas of open water water rather than with emergents [16].  Tall, dense vegetation provides good nesting cover for gadwalls.  As the vegetative cover increases, the potential for nest establishment and success increases.  Height and density of vegetation is assumed to be more important than species composition.  In a California study, most gadwall nests were in vegetation 13 to 36 inches (33-91 cm) tall that provided concealment on all sides and above. No nests were found in herbaceous cover less than 6 inches (15 cm) tall. Fifty-one percent of nests in North Dakota nesting fields were in herbaceous cover from 12 to 24 inches (30-60 cm) tall, while 47 percent were in cover less than 6 inches (15 cm) tall [16]. FOOD HABITS : Gadwalls are almost exclusively surface feeders.  They tend to feed in rather shallow marshes having abundant aquatic plant life growing close to the surface [6].  They sometimes feed in stubble fields for grain or in woods for acorns [19].  They mainly consume leaves and stems of aquatic plants but also eat insects, mollusks, crustaceans, amphibians, and fishes [9,16,19].  Aquatic plants commonly eaten by gadwalls include pondweed (Potamogeton spp.), widgeongrass (Ruppia maritima), saltgrass (Distichlis spp.), muskgrass (Chara spp.), eelgrass (Zostera marina), spikerush (Eleocharis spp.), spiked watermilfoil (Myriophyllum spicatum) and filamentous algae [9,16,19].  The two most prominent plants in the diet of gadwall in South Carolina are fragrant flatsedge (Cyperus odoratus) and Carolina redroot (Lachnanthes caroliniana).  Major animal foods include crustaceans, especially those belonging to the order Anostraca, and insects, especially adult and larval chironomids (Chironamidae) [16]. Recently hatched gadwalls in Alberta initially fed on invertebrates but were essentially herbiverous by 3 weeks of age.  Major animal foods of ducklings included adult and larval chironamids, water boatman (Cerixidae), beetles (Coleoptera), and cladocerans (Cladocera). Important plants in the duckling's diets were pondweed, green algae (Cladophoracea), duckweed (Lemna minor), and seeds of American sloughgrass (Beckmannia syzigachne) [16]. PREDATORS : Predators of gadwalls include humans, foxes (Vulpes spp.), raccoons (Procyon lotor), striped skunks (Mephitis mephitis), coyotes (Canis latrans), badgers (Taxidea taxus), weasels (Mustela spp.), minks (Mustela vison), crows (Corvus spp.), and magpies (Pica spp.) [8,9,12,14]. MANAGEMENT CONSIDERATIONS : Grazing and mowing often destroy preferred nesting cover for gadwalls. Although annual mowing or grazing is not recommended, mowing may be useful for maintaining vegetative cover in earlier, more productive successsional stages [16]. REFERENCES : NO-ENTRY


DIRECT FIRE EFFECTS ON ANIMALS : Late spring and summer fires may destroy gadwall nests [20].  Ducklings and molting adults are especially vulnerable to fire.  When not molting adult gadwalls can probably easily escape fire. HABITAT RELATED FIRE EFFECTS : Burning can change the growth form and pattern of nesting cover for gadwalls [20].  Gadwalls prefer nesting in dense cover [16], which can be destroyed by fire.  A study of the effects of nesting cover removal on breeding puddle ducks at Lower Souris National Wildlife Refuge, North Dakota, showed that after spring burning, nest densities of gadwalls were greater in areas where the vegetation was not burned [12]. Additionally, gadwall nests were significantly (P<0.01) less abundant in mowed meadows that would be expected by chance.  They made up 29 percent of all nests found, but only 13 percent of the nests were in mowed meadows.  Gadwalls will, however, use areas that have been burned if cover development is sufficent when they begin nesting [12].  Changes in vegetation cover induced by fire can also benefit gadwalls by destroying unwanted vegetation and increasing vegetation preffed by gadwalls [15]. FIRE USE : Wetlands can be burned to reverse plant succession to a subclimax plant community which is attractive to waterfowl [15].  Fire can be used to remove the accumulation of dead vegetation built up on marshes over the years and restore wetlands that are dominated with plants such as common reed (Phragmites communis). Desirable gadwall foods such as pondweed can be restored by burning.  Burning should be postponed until after the nesting season to avoid destroying nests [15]. REFERENCES : NO-ENTRY


REFERENCES : 1.  Bellrose, Frank C. 1980. Ducks, geese and swans of North America.        Harrisburg, PA: Stackpole Books. 3rd ed. 540 p.  [19802] 2.  Bent, Arthur Cleveland. 1962. Life histories of North American wild        fowl. Part 1. New York: Dover Publications, Inc. 244 p.  [20027] 3.  Bernard, Stephen R.; Brown, Kenneth F. 1977. Distribution of mammals,        reptiles, and amphibians by BLM physiographic regions and A.W. Kuchler's        associations for the eleven western states. Tech. Note 301. Denver, CO:        U.S. Department of the Interior, Bureau of Land Management. 169 p.        [434] 4.  Eyre, F. H., ed. 1980. Forest cover types of the United States and        Canada. Washington, DC: Society of American Foresters. 148 p.  [905] 5.  Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; [and others].        1977. Vegetation and environmental features of forest and range        ecosystems. Agric. Handb. 475. Washington, DC: U.S. Department of        Agriculture, Forest Service. 68 p.  [998] 6.  Johnsgard, Paul A. 1979. A guide to North American waterfowl.        Bloomington, IN: Indiana University Press. 274 p.  [20026] 7.  Johnson, Douglas H.; Grier, James W. 1988. Determinants of breeding        distribution of ducks. Wildlife Monographs. 100: 1-37.  [21350] 8.  Hines, J. E.; Mitchell, G. J. 1983. Gadwall nest-site selection and        nesting success. Journal of Wildlife Management. 47(4): 1063-1071.        [21351] 9.  Dahlsten, D. L.. 1986. Control of invaders. In: Mooney, Harold A.;        Drake, James A., eds. Ecology of Biological Invasions of North America        and Hawaii. Ecological Studies 58. New York: Springer-Verlag: 275-302.        [16144] 10.  Kuchler, A. W. 1964. Manual to accompany the map of potential vegetation        of the conterminous United States. Special Publication No. 36. New York:        American Geographical Society. 77 p.  [1384] 11.  Madge, Steve; Burn, Hilary. 1988. Waterfowl: An indentification guide to        the ducks, geese and swans of the world. Boston, MA: Houghton Mifflin        Company. 298 p.  [20029] 12.  Martz, Gerald F. 1967. Effects of nesting cover removal on breeding        puddle ducks. Journal of Wildlife Management. 31(2): 236-247.  [16284] 13.  Musgrove, Jack W.; Musgrove, Mary R. 1943. Waterfowl in Iowa. Des        Moines, IA: State Convservation Committee. 113 p. + index.  [20028] 14.  Sargeant, Alan B.; Allen, Stephen H.; Eberhardt, Robert T. 1984. Red fox        predation on breeding ducks in midcontinent North America. Wildlife        Monographs No. 89. Washington, DC: The Wildlife Society. 41 p.  [18149] 15.  Schlichtemeier, Gary. 1967. Marsh burning for waterfowl. In:        Proceedings, 6th annual Tall Timbers fire ecology conference; 1967 March        6-7; Tallahassee, FL. No. 6. Tallahassee, FL: Tall Timbers Research        Station: 40-46.  [16450] 16.  Sousa, Patrick J. 1985. Habitat suitability index models: gadwall        (breeding). Biological Report 82(10.100). Washington, DC: U.S.        Department of the Interior, Fish and Wildlife Service. 35 p.  [20031] 17.  Springer, Paul F.; Stewart, Robert E. 1977. Gadwall nesting in Maryland.        Auk. 67: 234-235.  [20042] 18.  Vermeer, Kees. 1970. Some aspects of the nesting of ducks on islands in        Lake Newell, Alberta. Journal of Wildlife Management. 34(1): 126-129.        [20041] 19.  DeGraaf, Richard M.; Scott, Virgil E.; Hamre, R. H.; [and others]. 1991.        Forest and rangeland birds of the United States: Natural history and        habitat use. Agric. Handb. 688. Washington, DC: U.S. Department of        Agriculture, Forest Service. 625 p.  [15856] 20.  Kruse, Arnold D.; Higgins, Kenneth F. 1990. Effects of prescribed fire        upon wildlife habitat in northern mixed-grass prairie. In: Alexander, M.        E.; Bisgrove, G. F., technical coordinators. The art and science of fire        management: Proceedings, 1st Interior West Fire Council annual meeting        and workshop; 1988 October 24-27; Kananaskis Village, AB. Inf. Rep.        NOR-X-309. Edmonton, AB: Forestry Canada, Northwest Region, Northern        Forestry Centre: 182-193.  [14146] 21.  Donohoe, Robert W. 1974. American hornbeam  Carpinus caroliniana Walt.        In: Gill, John D.; Healy, William M., eds. Shrubs and vines for        northeastern wildlife. Gen. Tech. Rep. NE-9. Upper Darby, PA: U.S.        Department of Agriculture, Forest Service, Northeastern Forest        Experiment Station: 86-88.  [13714]

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