View source for Gadwall

{{Short description|Species of bird}}
{{Other uses}}
{{Speciesbox
| name = Gadwall
| image = Gadwall-Anas-strepera.jpg
| image_caption = [[File:Mareca strepera - Gadwall XC436359.mp3|thumb|center|Calls recorded in the [[Netherlands]]]]
| image2 = Gadwall-female.jpg
| image2_caption = Female
| status = LC 
| status_system = IUCN3.1
| status_ref = <ref name=IUCN>{{cite iucn |author=BirdLife International |year=2016 |title=''Mareca strepera'' |page=e.T22680149A86020572 |doi=10.2305/IUCN.UK.2016-3.RLTS.T22680149A86020572.en |access-date=23 February 2022}}</ref>
| genus = Mareca
| species = strepera
| authority = ([[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]])
| subdivision_ranks = Subspecies
| subdivision = 
* ''M. s. strepera'' <small>([[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]])</small><br /><small>(common gadwall)</small>
* †''M. s. couesi'' <small>([[Thomas Hale Streets|Streets]], 1876)</small><br /><small>([[Coues's gadwall]] – [[extinct]])</small>
| synonyms = *''Anas strepera'' <small>Linnaeus, 1758</small>
| range_map = Mareca strepera map.svg
}}

The '''gadwall''' ('''''Mareca strepera''''') is a common and widespread [[dabbling duck]]<ref name=":0">{{Cite web|url=https://www.allaboutbirds.org/guide/Gadwall/lifehistory|title=Gadwall, Life history|website=All About Birds|publisher=Cornell Lab of Ornithology|access-date=12 April 2016}}</ref> in the family [[Anatidae]].

==Taxonomy==
The gadwall was first described by [[Carl Linnaeus]] in his landmark 1758 [[10th edition of Systema Naturae|10th edition of ''Systema Naturae'']].<ref name=Linnaeus/> [[DNA]] studies have shown that it is a [[Sister group|sister species]] with the [[falcated duck]]; the two are closely related to the three species of [[wigeon]]s, and all of them have been assigned to the genus ''[[Mareca]]''.<ref name=Johnson/><ref name=ioc>{{cite web| editor1-last=Gill | editor1-first=Frank | editor1-link=Frank Gill (ornithologist) | editor2-last=Donsker | editor2-first=David | year=2017 | title=Screamers, ducks, geese & swans | work=World Bird List Version 7.3 | url=http://www.worldbirdnames.org/bow/waterfowl/ | publisher=International Ornithologists' Union | access-date=23 July 2017}}</ref> There are two subspecies:<ref name=ITIS/>
* ''M. s. strepera'', the '''common gadwall''', described by Linnaeus, is the nominate subspecies.
* {{dagger}}''M. s. couesi'', [[Coues's gadwall]], [[extinct]] {{circa}} 1874, was formerly found only on [[Teraina]], a coral atoll in the Pacific Ocean.<ref name=Hume/>

The specific name ''strepera'' is Late Latin for "noisy".<ref name= job90>{{cite book | last= Jobling | first= James A | year= 2010| title= The Helm Dictionary of Scientific Bird Names | url= https://archive.org/details/helmdictionarysc00jobl_997 | url-access= limited | publisher = Christopher Helm | location = London | isbn = 978-1-4081-2501-4 |pages = [https://archive.org/details/helmdictionarysc00jobl_997/page/n46 46], 367}}</ref> The [[etymology]] of the word ''gadwall'' is not known, but the name has been in use since 1666.<ref name=merriam-webster/>

== Description ==
The gadwall is {{convert|47|–|58|cm|in|abbr=on}} long with a {{convert|78|–|85|cm|in|abbr=on}} wingspan.<ref name=Floyd>{{Cite book |last=Floyd |first=T. |year=2008 |title=Smithsonian Field Guide to the Birds of North America |publisher=HarperCollins |location=New York }}</ref> The male is slightly larger than the female, weighing on average {{convert|990|g|oz|abbr=on}} against her {{convert|850|g|oz|abbr=on}}.<ref name=Madge/> The breeding male is patterned grey, with a black rear end, light chestnut wings, and a brilliant white [[speculum feathers|speculum]], obvious in flight or at rest.<ref name=Dunn>{{cite book |last1=Dunn |first1=J. |last2=Alderfer |first2=J. |year=2006 |title=National Geographic Field Guide to the Birds of North America |edition=5th }}</ref> In non-breeding (eclipse) plumage, the drake looks more like the female, but retains the male wing pattern, and is usually greyer above and has less orange on the bill.<ref name=Madge/>

The female is light brown, with plumage much like a female [[mallard]]. It can be distinguished from that species by the dark orange-edged bill, smaller size, the white [[speculum feathers|speculum]], and white belly.<ref name=Dunn/> Both sexes go through two moults annually, following a juvenile moult.<ref name=Floyd/>

The gadwall is a quieter duck, except during its [[courtship display]]. Females give a call similar to the ''quack'' of a female mallard but higher-pitched, transcribed as ''gag-ag-ag-ag''. Males give a grunt, transcribed as ''mep'', and a whistle.<ref name=Madge/>

== Distribution ==
The gadwall breeds in the northern areas of Europe and across the [[Palearctic]], and central North America. In North America, its breeding range lies along the [[Saint Lawrence River]], through the [[Great Lakes]], [[Alberta]], [[Saskatchewan]], the [[Dakotas]], south to [[Kansas]], west to [[California]], and along coastal [[Pacific]] [[Canada]] and southern coastal [[Alaska]].<ref name=Floyd/><ref name=Dunn/> The range of this bird appears to be expanding into eastern North America. This [[dabbling duck]] is strongly [[bird migration|migratory]], and winters farther south than its breeding range, from coastal [[Alaska]], south into [[Central America]], and east into [[Idaho]], [[Kansas]], [[Ohio]], [[Virginia]], and then south all the way into Central America.<ref name=Floyd/><ref name=Dunn/>

In [[Great Britain]], the gadwall is a scarce-breeding bird and winter visitor, though its population has increased in recent years. It is likely that its expansion was partly through introduction, mainly to England, and partly through colonization by continental birds staying to breed in [[Scotland]]. In [[Ireland]] a small breeding population has recently become established, centred on [[County Wexford]] in the south and [[Lough Neagh]] in the north.<ref name=IrishBirds/> The Gadwall is also seen in some parts of [[South Asia]], particularly the southern part of [[India]].<ref>{{Cite news|last=Frederick|first=Prince|date=2020-12-26|title=Gadwalls join the party|language=en-IN|work=The Hindu|url=https://www.thehindu.com/society/gadwalls-join-the-party/article33422528.ece|access-date=2021-08-01|issn=0971-751X}}</ref>

== Behaviour ==
[[File:Gadwall (Anas strepera) female and male dabbling.jpg|thumb|Female and male dabbling, [[WWT London Wetland Centre]], [[Barnes, London|Barnes]]]]
The gadwall is a bird of open wetlands, such as [[prairie]] or [[steppe]] lakes, wet grassland or marshes with dense fringing vegetation, and usually feeds by dabbling for plant food with head submerged. They can also dive underwater for food, more proficiently than other dabbling ducks, and may also steal food from diving birds such as coots.<ref name=":1">{{Cite book |last=Todd |first=Frank S. |url=https://www.worldcat.org/oclc/36056940 |title=Natural history of the waterfowl |date=1996 |publisher=San Diego Natural History Museum |isbn=0-934797-11-0 |location=San Diego, Calif. |oclc=36056940}}</ref>  It nests on the ground, often some distance from water. It is not as gregarious as some dabbling ducks outside the breeding season and tends to form only small flocks.

Gadwalls are monogamous and may start breeding after their first year. Pair formation begins during fall migration or on breeding grounds, but has also been reported to occur in August when males are still in eclipse plumage. Gadwalls are generally quiet, except during courtship. The male utters a ''mep'' call during a display known as the ''burp'', where he raises his head pointing his bill towards a female.<ref>{{Cite journal |last=Dwyer |first=Thomas J. |date=1974 |title=Social Behavior of Breeding Gadwalls in North Dakota |url=https://www.jstor.org/stable/4084516 |journal=The Auk |volume=91 |issue=2 |pages=375–386 |jstor=4084516 |issn=0004-8038}}</ref> The ''grunt-whistle'' is similar to that of mallards, where the male rears his outstretched head with the bill dipped into water, displacing a stream of water droplets towards a nearby female as the bill is raised against the chest. During this display the male makes a loud whistle call followed by a low ''burp''.<ref>{{Cite book |last=Baldassarre |first=Guy A. |url=https://www.worldcat.org/oclc/810772720 |title=Ducks, geese, and swans of North America |date=2014 |isbn=978-1-4214-0751-7 |edition=2 |location=Baltimore |oclc=810772720}}</ref> Paired males may follow other females in flight displays.<ref name=":1" /><ref>{{Cite journal |last1=Crabtree |first1=Robert L. |last2=Broome |first2=Linda S. |last3=Wolfe |first3=Michael L. |date=1989 |title=Effects of Habitat Characteristics on Gadwall Nest Predation and Nest-Site Selection |url=https://www.jstor.org/stable/3801319 |journal=The Journal of Wildlife Management |volume=53 |issue=1 |pages=129–137 |doi=10.2307/3801319 |jstor=3801319 |issn=0022-541X|url-access=subscription }}</ref>

During nesting season, the female lays a clutch of 7–12 eggs with each of them measuring {{cvt|4.9-6|cm}} in length and {{cvt|3.4-4.4|cm}} in width. Incubation lasts for 24–27 days and the nestlings leave after around 1–2 days. A gadwall can only raise one brood a season<ref name=":0" />

== Conservation ==
Currently, the gadwall is listed as [[least concern]] in the [[IUCN Red List of Threatened Species]].<ref name="IUCN" />  The gadwall is one of the species to which the ''Agreement on the Conservation of African-Eurasian Migratory Waterbirds'' ([[AEWA]]) applies. Populations have increased approximately 2.5% over the course of 49 years (from 1966 to 2010), and continue to grow. Gadwalls are one of the most hunted duck species (3rd to the [[mallard]] and [[green-winged teal]]), with 1.7 million shot each year.<ref>{{Cite web |title=Gadwalls: The Wonder Duck {{!}} Ducks Unlimited |url=https://www.ducks.org/conservation/waterfowl-research-science/gadwalls-the-wonder-duck |access-date=2024-02-17 |website=www.ducks.org |language=en}}</ref>

Because of the efforts of the United States and Canadian groups [[Ducks Unlimited]], [[Delta Waterfowl Foundation]] and other private conservation groups, the species continues to be sustainably hunted there.<ref name=":0"/>


==Gallery==
<gallery mode="packed" heights="130">
File:Gadwall Nest.jpg|Nest lined with feathers
File:Anas strepera MWNH 1983.JPG|Eggs, collection [[Museum Wiesbaden]]
File:Gadwall (Anas strepera) female and male.jpg|Female and male, [[WWT London Wetland Centre]], [[Barnes, London|Barnes]]
File:Snatterand ( Anas strepera) Ystad-2020.jpg|Three males and two females resting
File:Anas strepera M F.JPG|Male and female on the [[Lake Ontario]]
File:Gadwalls in flight, Taudaha Lake.jpg|Gadwalls in flight, [[Taudaha Lake]]
</gallery>

== References ==
{{Reflist|refs=

<ref name=Hume>{{Cite book |last1=Hume |first1=Julian P. |first2=Michael |last2=Walters |title=Extinct Birds |year=2012 |location=London, UK |publisher=T. & A. D. Poyser |pages=48 |isbn=978-1-4081-5725-1 |url=https://books.google.com/books?id=xpUBocGB12YC&pg=PA48 |access-date=10 August 2014}}</ref>

<ref name=IrishBirds>{{cite journal |journal=Irish Birds |volume=9 | issue=1 |year=2010 |page=68 |title=Gadwall}}</ref>

<ref name=ITIS>{{cite web |url=https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=175073 |title=ITIS Report: ''Anas strepera'' |publisher=[[Integrated Taxonomic Information System]] |access-date=10 August 2014}}</ref>

<ref name= Johnson>{{Cite journal |last1=Johnson |first1=Kevin P. |last2=Sorenson |first2=Michael D. |year=1999 |title=Phylogeny and biogeography of dabbling ducks (genus: ''Anas''): A comparison of molecular and morphological evidence | journal=The Auk |volume=116 |issue=3 |pages=792–805 |url=http://sora.unm.edu/sites/default/files/journals/auk/v116n03/p0792-p0805.pdf |doi=10.2307/4089339|jstor=4089339 }}</ref>

<ref name=Linnaeus>{{Cite book |last=Linnaeus |first=C. |author-link=Carl Linnaeus |title=Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata. |location=Holmiae [Stockholm] |publisher=Laurentii Salvii |year=1758 |quote=A. macula alarum rufa nigra alba. |language=la |page=125 |url=https://www.biodiversitylibrary.org/item/10277#page/143/mode/1up |access-date=10 August 2014}}</ref>

<ref name=Madge>{{Cite book |last1=Madge |first1=Steve |last2=Burn |first2=Hilary |title=Wildfowl: An Identification Guide to the Ducks, Geese and Swans of the World |year=1988 |publisher=Christopher Helm |pages=200–202 |isbn=0-7470-2201-1}}</ref>

<ref name=merriam-webster>{{cite encyclopedia |url=http://www.merriam-webster.com/dictionary/gadwall |title=gadwall |encyclopedia=Merriam-Webster |access-date=24 August 2011}}</ref>
}}

== Literature cited ==
* {{cite journal |journal=Forktail |volume=15 |page=87 |title=Preliminary notes on some birds in Bhutan |first=K. David |last=Bishop |year=1999 |url=http://orientalbirdclub.org/wp-content/uploads/2012/09/Bishop-Bhutan.pdf |access-date=2014-11-30 |archive-url=https://web.archive.org/web/20150612023923/http://orientalbirdclub.org/wp-content/uploads/2012/09/Bishop-Bhutan.pdf |archive-date=2015-06-12 |url-status=dead }}
* {{Cite book |last=Clements |first=James |year=2007 |url=http://www.cornellpress.cornell.edu/cup_detail.taf?ti_id=4566 |title=The Clements Checklist of the Birds of the World |publisher=Cornell University Press |location=Ithaca}}
*Gadwall Duck Journal (Anas Strepera): 150 Page Lined Notebook/diary. N.p.: CreateSpace Publishing Platform, 2018. ISBN 9781724968739

== External links ==
{{Commons category}}
{{Wikispecies|Anas strepera}}
{{EB1911 poster|Gadwall}}
* {{BirdLife|22680149|Anas strepera}}
* [https://www.rspb.org.uk/birds-and-wildlife/gadwall RSPB Birds by Name Gadwall Page]
* [http://www.birds.cornell.edu/AllAboutBirds/BirdGuide/Gadwall.html Gadwall Species Account] – Cornell Lab of Ornithology
* [https://web.archive.org/web/20080916062958/http://www.mbr-pwrc.usgs.gov/id/framlst/i1350id.html Gadwall – ''Anas strepera''] – USGS Patuxent Bird Identification InfoCenter
* [http://www.massaudubon.org/our-conservation-work/wildlife-research-conservation/statewide-bird-monitoring/breeding-bird-atlases/bba2/find-a-bird/(id)/136 Gadwal at the Massachusetts Breeding Bird Atlas] {{Webarchive|url=https://web.archive.org/web/20140108123612/http://www.massaudubon.org/our-conservation-work/wildlife-research-conservation/statewide-bird-monitoring/breeding-bird-atlases/bba2/find-a-bird/(id)/136 |date=2014-01-08 }}
* {{InternetBirdCollection|gadwall-anas-strepera}}
* {{VIREO|Gadwall}}
* [http://www.ornithos.de/Ornithos/Feather_Collection/Anas_strepera/Anas_strepera.htm Feathers of gadwall (''Anas strepera'')] {{Webarchive|url=https://web.archive.org/web/20131213053321/http://www.ornithos.de/Ornithos/Feather_Collection/Anas_strepera/Anas_strepera.htm |date=2013-12-13 }}

{{North American Game}}
{{Taxonbar |from1=Q25889|from2=Q28106966}}
{{Authority control}}

[[Category:Mareca]]
[[Category:Ducks]]
[[Category:Holarctic birds]]
[[Category:Birds described in 1758]]
[[Category:Taxa named by Carl Linnaeus]]