Mareca strepera - (Linnaeus, 1758)
Gadwall
Other English Common Names: gadwall
Synonym(s): Anas strepera Linnaeus, 1758
Taxonomic Status: Accepted
Related ITIS Name(s): Anas strepera Linnaeus, 1758 (TSN 175073)
French Common Names: canard chipeau
Spanish Common Names: Pato Friso
Unique Identifier: ELEMENT_GLOBAL.2.101166
Element Code: ABNJB10160
Informal Taxonomy: Animals, Vertebrates - Birds - Waterfowl
 
Kingdom Phylum Class Order Family Genus
Animalia Craniata Aves Anseriformes Anatidae Mareca
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Concept Reference
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Concept Reference: American Ornithologists' Union (AOU). 1998. Check-list of North American birds. Seventh edition. American Ornithologists' Union, Washington, D.C. [as modified by subsequent supplements and corrections published in The Auk]. Also available online: http://www.aou.org/.
Concept Reference Code: B98AOU01NAUS
Name Used in Concept Reference: Anas strepera
Taxonomic Comments: Considered by some authors as two separate species, A. strepera (common gadwall) and A. couesi (Coues' gadwall), the latter now extinct (AOU 1983). Formerly (AOU 1983, 1998) considered part of Anas, but now treated as separate on the basis of genetic data (Gonzalez et al. 2009) which indicate that Anas as previously constituted was paraphyletic, and further that it consisted of four deeply divergent clades, now recognized as the separate genera Sibirionetta, Spatula, Mareca, and Anas (cf. Livezey 1991). Linear sequence of genera and species follows Gonzalez et al. (2009). (AOU 2017).
Conservation Status
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NatureServe Status

Global Status: G5
Global Status Last Reviewed: 06Apr2016
Global Status Last Changed: 21Nov1996
Ranking Methodology Used: Ranked by inspection
Rounded Global Status: G5 - Secure
Nation: United States
National Status: N5B,N5N (05Jan1997)
Nation: Canada
National Status: N5B,N5N,N5M (29Jan2018)

U.S. & Canada State/Province Status
Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
United States Alabama (S5N), Alaska (S4B), Arizona (S5), Arkansas (S5N), California (SNRB,SNRN), Colorado (S5B), Connecticut (S2B,S4N), Delaware (S3B,S4N), Florida (SNRN), Georgia (S4), Idaho (S3), Illinois (SNA), Indiana (SNA), Iowa (S4N), Kansas (S1B,S5N), Kentucky (S4N), Louisiana (S5N), Maine (S1?B), Maryland (S2B,S4N), Massachusetts (S2B,S4M), Michigan (SNRN), Minnesota (SNRB), Mississippi (S4N), Missouri (SNRN,SNRM), Montana (S5B), Navajo Nation (S3), Nebraska (S4), Nevada (S4B,S5N), New Hampshire (SNA), New Jersey (S5), New Mexico (S4B,S5N), New York (S3), North Carolina (S2B,S4N), North Dakota (SNRB), Oklahoma (S5N), Oregon (S5), Pennsylvania (S3N), Rhode Island (S1B), South Carolina (SNRN), South Dakota (S5B), Tennessee (S4N), Texas (S3B,S5N), Utah (S4S5B,S4N), Vermont (S1B), Virginia (S2B,S4N), Washington (S4N,S5B), West Virginia (S3N), Wisconsin (S3B), Wyoming (S4N,S5B)
Canada Alberta (S5), British Columbia (S5B), Manitoba (S5B), New Brunswick (S2B,S3M), Newfoundland Island (SNA), Northwest Territories (SUB), Nova Scotia (S2B), Ontario (S4), Prince Edward Island (S4B,S2N), Quebec (S4S5), Saskatchewan (S5B,S5M,S2N), Yukon Territory (S3B)

Other Statuses

IUCN Red List Category: LC - Least concern

NatureServe Global Conservation Status Factors

Range Extent: >2,500,000 square km (greater than 1,000,000 square miles)
Range Extent Comments: BREEDS: North America: southern Alaska, southern Yukon, southern Mackenzie (north to near Yellowknife; Can. Field-Nat. 106:254-256), northern Saskatchewan, central Manitoba, southern Ontario, southwestern Quebec, Prince Edward Island, Anticosti Island (rarely), and the New Brunswick-Nova Scotia border south locally to southern California, southern Nevada, northern Arizona, southern New Mexico, northern Texas, southern Kansas, Iowa, centralMinnesota, southern Wisconsin, northern Ohio, northern Pennsylvania (formerly), and, on the Atlantic coast, to North Carolina (one isolated breeding area in northern Alabama); also in the Old World (AOU 1983). Highest breeding densities occur in the northern Great Plains and intermountain valleys of the western U.S.; some portions of Alaskan, Pacific, and Atlantic coasts also have important breeding populations (Ringelman 1990). Range may be expanding eastward. WINTERS: North America: southern Alaska, southern British Columbia, Idaho, Colorado, southern South Dakota, Iowa, the southern Great Lakes, and Chesapeake Bay on the Atlantic coast (rarely from New Brunswick and Nova Scotia) south to northern Baja California, Oaxaca, the state of Mexico, Puebla, Veracruz, Tabasco, Yucatan, the Gulf Coast, Florida, the Bahamas, western Cuba, and (formerly) Jamaica; also in Old World (AOU 1983). Major wintering areas include coastal Louisiana and Texas, Gulf Coast of Mexico to Yucatan Peninsula, central and southern Atlantic coast of U.S., Central Valley of California, and much of the west coast of Mexico (Ringelman 1990); also northwestern Utah (Bear River refuge) and southeastern Missouri (Mingo refuge) (Root 1988). Formerly resident (COUESI group) in the northern Line Islands (Washington and New York islands); now extinct (AOU 1983).

Short-term Trend Comments: Although the primary breeding habitat is in drought-prone and degraded habitats of the northern Great Plains, the continental population has remained relatively stable while those of other dabbling ducks have delined (Ringelman 1990). Breeding populations increasing in Great Basin region, intermountain valleys of Rockies, and in Pacific Flyway (Ringelman 1990). Breeding Bird Survey data indicate a significant population increase in North America between 1966 and 1989 (Droege and Sauer 1990). Overall, reproductive success was excellent in the mid-1990s (USFWS).

Other NatureServe Conservation Status Information

Distribution
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Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) BREEDS: North America: southern Alaska, southern Yukon, southern Mackenzie (north to near Yellowknife; Can. Field-Nat. 106:254-256), northern Saskatchewan, central Manitoba, southern Ontario, southwestern Quebec, Prince Edward Island, Anticosti Island (rarely), and the New Brunswick-Nova Scotia border south locally to southern California, southern Nevada, northern Arizona, southern New Mexico, northern Texas, southern Kansas, Iowa, centralMinnesota, southern Wisconsin, northern Ohio, northern Pennsylvania (formerly), and, on the Atlantic coast, to North Carolina (one isolated breeding area in northern Alabama); also in the Old World (AOU 1983). Highest breeding densities occur in the northern Great Plains and intermountain valleys of the western U.S.; some portions of Alaskan, Pacific, and Atlantic coasts also have important breeding populations (Ringelman 1990). Range may be expanding eastward. WINTERS: North America: southern Alaska, southern British Columbia, Idaho, Colorado, southern South Dakota, Iowa, the southern Great Lakes, and Chesapeake Bay on the Atlantic coast (rarely from New Brunswick and Nova Scotia) south to northern Baja California, Oaxaca, the state of Mexico, Puebla, Veracruz, Tabasco, Yucatan, the Gulf Coast, Florida, the Bahamas, western Cuba, and (formerly) Jamaica; also in Old World (AOU 1983). Major wintering areas include coastal Louisiana and Texas, Gulf Coast of Mexico to Yucatan Peninsula, central and southern Atlantic coast of U.S., Central Valley of California, and much of the west coast of Mexico (Ringelman 1990); also northwestern Utah (Bear River refuge) and southeastern Missouri (Mingo refuge) (Root 1988). Formerly resident (COUESI group) in the northern Line Islands (Washington and New York islands); now extinct (AOU 1983).

U.S. States and Canadian Provinces

Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
Color legend for Distribution Map
NOTE: The maps for birds represent the breeding status by state and province. In some jurisdictions, the subnational statuses for common species have not been assessed and the status is shown as not-assessed (SNR). In some jurisdictions, the subnational status refers to the status as a non-breeder; these errors will be corrected in future versions of these maps. A species is not shown in a jurisdiction if it is not known to breed in the jurisdiction or if it occurs only accidentally or casually in the jurisdiction. Thus, the species may occur in a jurisdiction as a seasonal non-breeding resident or as a migratory transient but this will not be indicated on these maps. See other maps on this web site that depict the Western Hemisphere ranges of these species at all seasons of the year.
Endemism: occurs (regularly, as a native taxon) in multiple nations

U.S. & Canada State/Province Distribution
United States AK, AL, AR, AZ, CA, CO, CT, DE, FL, GA, IA, ID, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, MT, NC, ND, NE, NH, NJ, NM, NN, NV, NY, OK, OR, PA, RI, SC, SD, TN, TX, UT, VA, VT, WA, WI, WV, WY
Canada AB, BC, MB, NB, NF, NS, NT, ON, PE, QC, SK, YT

Range Map
Note: Range depicted for New World only. The scale of the maps may cause narrow coastal ranges or ranges on small islands not to appear. Not all vagrant or small disjunct occurrences are depicted. For migratory birds, some individuals occur outside of the passage migrant range depicted. For information on how to obtain shapefiles of species ranges see our Species Mapping pages at www.natureserve.org/conservation-tools/data-maps-tools.

Range Map Compilers: NatureServe, 2002; WILDSPACETM 2002


U.S. Distribution by County Help
State County Name (FIPS Code)
CT Middlesex (09007)*, New London (09011)*
ID Ada (16001), Bear Lake (16007), Bingham (16011), Blaine (16013), Bonner (16017), Boundary (16021), Camas (16025), Canyon (16027), Cassia (16031), Custer (16037), Elmore (16039), Fremont (16043), Gooding (16047), Jefferson (16051), Kootenai (16055), Nez Perce (16069), Power (16077)
RI Washington (44009)
VA Northampton (51131)
VT Grand Isle (50013)
WY Sublette (56035)
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
01 Lower Connecticut (01080205)+*, Pawcatuck-Wood (01090005)+
02 Long Island Sound (02030203)+*, Eastern Lower Delmarva (02040304)+
04 Lake Champlain (04150408)+
14 Big Sandy (14040104)+
16 Bear Lake (16010201)+
17 Lower Kootenai (17010104)+, Pend Oreille Lake (17010214)+, Coeur D'alene Lake (17010303)+, Upper Spokane (17010305)+, Idaho Falls (17040201)+, Upper Henrys (17040202)+, American Falls (17040206)+, Lake Walcott (17040209)+, Raft (17040210)+, Upper Snake-Rock (17040212)+, Beaver-Camas (17040214)+, Camas (17040220)+, Little Wood (17040221)+, Middle Snake-Succor (17050103)+, Lower Boise (17050114)+, Middle Snake-Payette (17050115)+, Lower Snake-Asotin (17060103)+, Upper Salmon (17060201)+, Clearwater (17060306)+
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
Ecology & Life History
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Reproduction Comments: Breeding usually begins in mid-April in the south to early June in the north. Clutch size: usually about 9-11. Incubation: about 4 weeks, by female. Young are tended by female, can fly at 49-63 days. Relatively high percentage of yearlings do not breed. Up to at least a few hundred nests/ha on islands lacking mammalian predators.
Ecology Comments: Molting males may form groups of hundreds or thousands in mid-summer. Annual survivorship of adults banded in Colorado was 69-75% (Szymczak and Rexstad 1991).
Non-Migrant: Y
Locally Migrant: Y
Long Distance Migrant: Y
Mobility and Migration Comments: Partially migratory. Migratory populations move northward in spring, departing wintering areas by March or early April, usually arriving at northernmost breeding grounds late April-early May; move southward September-October (sometimes later) (Ringelman 1990, Terres 1980). Primary migration corridor originates in the prairies and extends through the low plains region of the central and south-central U.S. and into Mexico; secondary migration routes link the prairies with the Pacific Northwest, northern and central California, and northern Utah; Utah breeders winter in central and southern California and Mexico; migrates also along diagonal routes from Great Plains to central and southern Atlantic coast (Ringelman 1990). Gadwalls banded in breeding areas in north-central Colorado were recovered primarily near the banding areas and in central and coastal Texas, northern Utah, along the east and west coast of Mexico, and in the Interior Highlands of Mexico (Szymczak and Rexstad 1991).
Estuarine Habitat(s): Bay/sound, Herbaceous wetland, Lagoon, River mouth/tidal river, Tidal flat/shore
Riverine Habitat(s): Low gradient
Lacustrine Habitat(s): Shallow water
Palustrine Habitat(s): HERBACEOUS WETLAND, Riparian
Terrestrial Habitat(s): Cropland/hedgerow, Grassland/herbaceous
Habitat Comments: Lakes, ponds, rivers, marshes. Prefers freshwater but may be found on any open water during migration and winter. Moderate- to large-sized wetland of a permanent or semipermanent nature, expanses of open water with submersed vegetation, and open undisturbed shorelines are important molting habitats (Ringelman 1990).

Nests in thick vegetation near freshwater lakes, ponds, or streams, including open brackish or alkaline waters. Nests usually in dry upland site under clump of shrubs or in herbaceous vegetation, average of 300 m from water. Tends to nest near semipermanent wetlands that are relatively resistant to drought (Ringelman 1990). Commonly uses man-made ponds. May nest on island, upland meadow or grassland. Suitable nesting islands should be 0.1-0.5 ha in size, elongate, and separated from mainland by at least 150 m of water that remains 0.9 m deep in nesting season (Ringelman 1990). Successful breeders usually return to nesting area used the previous year (Szymczak and Rexstad 1991). A diversity of wetland types is required for successful reproduction, so that brood-rearing habitat is near nesting habitat; females will move brood up to 1.9 km to brood habitat (Ringelman 1990).

Adult Food Habits: Granivore, Herbivore
Immature Food Habits: Granivore, Herbivore
Food Comments: Feeds on leaves, stems, and tubers of aquatic plants. Also eats algae and seeds of sedges and grasses. Occasionally grazes in pastures and grain fields; may feed on acorns. Eats some small fishes and aquatic invertebrates (e.g., insects, crustaceans). Aquatic invertebrates comprise about half the diet in spring and summer; eats green portions of aquatic plants in non-nesting season; feeds generally in water 15-66 cm deep (Ringelman 1990). Juveniles intitally eat equal amount of animal and plant food; plant food begins to dominate after 2 weeks (Ringelman 1990).
Adult Phenology: Circadian
Immature Phenology: Circadian
Length: 51 centimeters
Weight: 990 grams
Economic Attributes
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Economic Comments: Lightly harvested; comprises 4.2% of continental duck breeding population, but only 2.5% of harvest (Ringelman 1990).
Management Summary
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Management Requirements: Wetland management to benefit gadwalls should be directed at maintaining large wetlands with stable water levels suitable for the growth of submersed aquatic vegetation (Ringelman 1990). See Barker et al. (1990) for information on the effects of different livestock grazing systems on nesting success in North Dakota. See Marcy (1986) for specifications for the construction and placement of wire nest baskets.
Population/Occurrence Delineation
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Group Name: Dabbling Ducks

Use Class: Breeding
Minimum Criteria for an Occurrence: Evidence of historical breeding, or current and likely recurring breeding, at a given location, minimally a reliable observation of one or more breeding pairs in appropriate habitat. Be cautious about creating EOs for observations that may represent single breeding events outside the normal breeding distribution.
Separation Barriers: None.
Separation Distance for Unsuitable Habitat: 10 km
Separation Distance for Suitable Habitat: 10 km
Separation Justification: Separation distance a compromise between three times average home range diameters (about 5-6 kilometers), and the great mobility of these birds. Home ranges: female Black Duck, mean 130 hectares during prelaying and laying period (n = 7, Ringelman et al. 1982); Mallards, mean 283 hectares (Dzubin 1955), 210 hectares (females) and 240 hectares (males) (Gilmer et al. 1975).
Breeding site fidelity: female Black Ducks in New England, 25% returned to nest in the following year, most within 91 meters of previous nest (Coulter and Miller 1968).

Inferred Minimum Extent of Habitat Use (when actual extent is unknown): 1.6 km
Inferred Minimum Extent Justification: Diameter of average home range of Mallards (Gilmer et al. 1975).
Date: 08Mar2001
Author: Cannings, S.

Use Class: Migratory stopover
Subtype(s): Staging area, Foraging area, Roosting area
Minimum Criteria for an Occurrence: Evidence of recurring presence of migrating or staging flocks (including historical); and potential recurring presence at a given location, minimally a reliable observation of 25 birds/0.5 square kilometer in appropriate habitat. Occurrences should be locations where the species is resident for some time during the appropriate season; it is preferable to have observations documenting presence over at least 7 days annually. Be cautious about creating EOs for observations that may represent single events.
Separation Distance for Unsuitable Habitat: 10 km
Separation Distance for Suitable Habitat: 10 km
Separation Justification: Separation distance somewhat arbitrary; set at 10 kilometers to define occurrences of managable size for conservation purposes. Occurrences defined primarily on the basis of areas supporting concentrations of foraging birds, rather than on the basis of distinct populations.
Date: 11Apr2002
Author: Cannings, S.

Use Class: Nonbreeding
Subtype(s): Molting area, Wintering area, Non-breeding feeding concentration area, Roosting area
Minimum Criteria for an Occurrence: Evidence of recurring presence of molting or wintering flocks (including historical); and potential recurring presence at a given location, minimally a reliable observation of 25 birds/0.5 square kilometer in appropriate habitat. Occurrences should be locations where the species is resident for some time during the appropriate season; it is preferable to have observations documenting presence over at least 20 days annually. Be cautious about creating EOs for observations that may represent single events.
Mapping Guidance: Map roosting and feeding areas with separate polygons in same EO.
Separation Barriers: None.
Separation Distance for Unsuitable Habitat: 10 km
Separation Distance for Suitable Habitat: 10 km
Separation Justification: Separation distance somewhat arbitrary; set at 10 kilometers to define occurrences of managable size for conservation purposes. Wintering flocks of American Black Ducks fly an average of 10 kilometres from roost to foraging area, but have been recorded flying up to 43 kilometres (Frazer et al. 1990). However, occurrences defined primarily on the basis of areas supporting concentrations of foraging birds, rather than on the basis of distinct populations.
Date: 29May2001
Author: Cannings, S.
Population/Occurrence Viability
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U.S. Invasive Species Impact Rank (I-Rank) Not yet assessed
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Authors/Contributors
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Element Ecology & Life History Edition Date: 21Aug1995
Element Ecology & Life History Author(s): HAMMERSON, G.

Zoological data developed by NatureServe and its network of natural heritage programs (see Local Programs) and other contributors and cooperators (see Sources).

References
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  • Yukon Bird Club. 2004. Yukon Warbler: Newsletter of the Yukon Bird Club - Spring 2004. 32pp.

  • Yukon Bird Club. 2008. Yukon Warbler: Newsletter of the Yukon Bird Club - Fall 2008. 26pp.

  • Yukon Bird Club. 2009. Yukon Warbler: Newsletter of the Yukon Bird Club - Spring 2009. 36pp.

  • Yukon Bird Club. 2011. Yukon Warbler: Newsletter of the Yukon Bird Club - Spring 2011. 24pp.

  • Yukon Bird Club. 2013. Yukon Warbler: Newsletter of the Yukon Bird Club - Fall 2013. 16pp.

  • Yukon Bird Club. 2014. Yukon Warbler: Newsletter of the Yukon Bird Club - Fall-Winter 2014.12 pp.

  • Yukon Bird Club. 2015. Yukon Warbler: Newsletter of the Yukon Bird Club - Winter 2015. 16pp.

  • eBird. 2016. eBird: An online database of bird distribution and abundance [web application]. eBird, Cornell Lab of Ornithology, Ithaca, New York. Available: http://www.ebird.org. Accessed in 2016.

Use Guidelines & Citation

Use Guidelines and Citation

The Small Print: Trademark, Copyright, Citation Guidelines, Restrictions on Use, and Information Disclaimer.

Note: All species and ecological community data presented in NatureServe Explorer at http://explorer.natureserve.org were updated to be current with NatureServe's central databases as of March 2018.
Note: This report was printed on

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Citation for data on website including State Distribution, Watershed, and Reptile Range maps:
NatureServe. 2018. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://explorer.natureserve.org. (Accessed:

Citation for Bird Range Maps of North America:
Ridgely, R.S., T.F. Allnutt, T. Brooks, D.K. McNicol, D.W. Mehlman, B.E. Young, and J.R. Zook. 2003. Digital Distribution Maps of the Birds of the Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA.

Acknowledgement Statement for Bird Range Maps of North America:
"Data provided by NatureServe in collaboration with Robert Ridgely, James Zook, The Nature Conservancy - Migratory Bird Program, Conservation International - CABS, World Wildlife Fund - US, and Environment Canada - WILDSPACE."

Citation for Mammal Range Maps of North America:
Patterson, B.D., G. Ceballos, W. Sechrest, M.F. Tognelli, T. Brooks, L. Luna, P. Ortega, I. Salazar, and B.E. Young. 2003. Digital Distribution Maps of the Mammals of the Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA.

Acknowledgement Statement for Mammal Range Maps of North America:
"Data provided by NatureServe in collaboration with Bruce Patterson, Wes Sechrest, Marcelo Tognelli, Gerardo Ceballos, The Nature Conservancy-Migratory Bird Program, Conservation International-CABS, World Wildlife Fund-US, and Environment Canada-WILDSPACE."

Citation for Amphibian Range Maps of the Western Hemisphere:
IUCN, Conservation International, and NatureServe. 2004. Global Amphibian Assessment. IUCN, Conservation International, and NatureServe, Washington, DC and Arlington, Virginia, USA.

Acknowledgement Statement for Amphibian Range Maps of the Western Hemisphere:
"Data developed as part of the Global Amphibian Assessment and provided by IUCN-World Conservation Union, Conservation International and NatureServe."

NOTE: Full metadata for the Bird Range Maps of North America is available at:
http://www.natureserve.org/library/birdDistributionmapsmetadatav1.pdf.

Full metadata for the Mammal Range Maps of North America is available at:
http://www.natureserve.org/library/mammalsDistributionmetadatav1.pdf.

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