View source for Mallard

{{short description|Species of duck}}
{{Other uses}}

{{good article}}

{{Use British English|date=September 2025}}
{{Use dmy dates|date=March 2018}}

{{speciesbox
| name = Mallard
| fossil_range = {{Fossil range|Zanclean|present|ref={{efn|Fossil remains are known from between 5.33 and 3.6 million years ago.<ref>{{Cite web |title=Anas platyrhynchos |url=https://www.mindat.org/taxon-9761484.html |access-date=1 Sep 2025 |website=www.mindat.org |language=en}}</ref>}}}}
| image = Anas platyrhynchos male female quadrat.jpg
| image_caption = Female (left) and male (right) in [[Straßlach-Dingharting]], Germany
| image2 = Anas platyrhynchos - Mallard - XC62258.ogg
| image2_caption = 
| status = LC
| status_system = IUCN3.1
| status_ref = <ref name="IUCN">{{Cite iucn |author=BirdLife International |date=2019 |title=''Anas platyrhynchos'' |amends=2017 |article-number=e.T22680186A155457360 |doi=10.2305/IUCN.UK.2019-3.RLTS.T22680186A155457360.en |access-date=23 February 2022}}</ref>
| status2 = G5
| status2_system = TNC
| status2_ref = <ref>{{Cite web |title=Anas platyrhynchos |url=https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.1168407/Anas_platyrhynchos |archive-url=https://web.archive.org/web/20250120032559/https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.1168407/Anas_platyrhynchos |url-status=live |archive-date=20 January 2025 |access-date=17 April 2024 |website=[[NatureServe]] Explorer}}</ref>
| genus = Anas
| species = platyrhynchos
| authority = [[Carl Linnaeus|Linnaeus]], 1758
| subdivision_ranks = Subspecies
| subdivision = ''A. p. platyrhynchos'' <small>Linnaeus, 1758</small><br />
''A. p. conboschas'' <small>[[Christian Ludwig Brehm|C. L. Brehm]], 1831</small>
| synonyms = *''Anas boschas'' {{small|Linnaeus,&nbsp;1758}}
* ''Anas adunca'' {{small|Linnaeus,&nbsp;1758}}
| range_map = AnasPlatyrhynchosIUCN2019 2.png
| range_map_caption = Range of '' A. platyrhynchos''{{leftlegend|#00FF00|Breeding|outline=gray}} {{leftlegend|#008000|Resident|outline=gray}} {{leftlegend|#00FFFF|Passage|outline=gray}} {{leftlegend|#007FFF|Non-breeding|outline=gray}} {{leftlegend|#FF00FF|Vagrant (seasonality uncertain)|outline=gray}} {{leftlegend|#FF80FF|Possibly extant and introduced|outline=gray}} {{leftlegend|#a76f3b|Extant and introduced (seasonality uncertain) |outline=gray}} {{leftlegend|#DFDF00|Possibly extant and introduced (seasonality uncertain)|outline=gray}}
}}
{{birdsong|url=https://xeno-canto.org/species/Anas-platyrhynchos|species=Mallard}}

The '''mallard''' ({{IPAc-en|ˈ|m|æ|l|ɑr|d|,_|ˈ|m|æ|l|ər|d}}) or '''wild duck''' ('''''Anas platyrhynchos''''') is a [[dabbling duck]] that breeds throughout the temperate and subtropical [[Americas]], [[Eurasia]], and [[North Africa]]. It has been [[introduced species|introduced]] to [[New Zealand]], [[Australia]], [[Peru]], [[Brazil]], [[Uruguay]], [[Argentina]], [[Chile]], [[Colombia]], the [[Falkland Islands]], and [[South Africa]]. Belonging to the [[subfamily]] [[Anatinae]] of the [[Anseriformes|waterfowl]] family [[Anatidae]], mallards live in [[wetland]]s, eat water plants and small animals, and are [[social animal]]s preferring to congregate in groups or flocks of varying sizes.

Males (drakes) have green heads, while the females (hens) have mainly brown-speckled [[plumage]]. Both sexes have an area of white-bordered black or [[iridescent]] purple or blue feathers called a [[speculum feathers|speculum]] on their wings; males especially tend to have blue speculum feathers. The mallard is {{convert|50|–|65|cm|abbr=on|in}} long, of which the body makes up around two-thirds the length. The wingspan is {{convert|81|–|98|cm|abbr=on|in}} and the [[Beak|bill]] is {{convert|4.4|to|6.1|cm|abbr=on|in}} long. It is often slightly heavier than most other dabbling ducks, weighing {{convert|0.7|–|1.6|kg|abbr=on|lb}}.

The female lays 8 to 13 creamy white to greenish-buff spotless [[Bird egg|eggs]], on alternate days. [[Egg incubation|Incubation]] takes 27 to 28 days and [[Fledge|fledging]] takes 50 to 60 days. The ducklings are [[precocial]] and fully capable of swimming as soon as they hatch.

The non-migratory mallard interbreeds with indigenous wild ducks of closely related species through [[genetic pollution]] by producing fertile offspring. Complete hybridisation of various species of wild duck gene pools could result in the extinction of many indigenous waterfowl. This species is the main ancestor of most breeds of [[domestic duck]], and its naturally evolved wild gene pool has been genetically polluted by the domestic and feral mallard populations.

The mallard is considered to be a [[species of least concern]] by the [[International Union for Conservation of Nature]] (IUCN), and, unlike many waterfowl, are considered an [[invasive species]] in some regions. It is a very adaptable species, being able to live and even thrive in urban areas which may have supported more localised, sensitive species of waterfowl before development.

== Taxonomy and evolutionary history ==
The mallard was one of the many [[Aves in the 10th edition of Systema Naturae|bird species originally described]] in the 1758 10th{{nbsp}}edition of ''[[Systema Naturae]]'' by [[Carl Linnaeus]].<ref name="Linnaeus1758" /> He gave it two [[Binomial nomenclature|binomial name]]s: ''Anas platyrhynchos'' and ''Anas boschas''.<ref>{{Cite book|url=https://books.google.com/books?id=-RfSBAAAQBAJ&q=Anas+boschas+Linnaeus,+1758&pg=PA75|title=Helm Dictionary of Scientific Bird Names|last=Jobling|first=James A.|date=2010|publisher=Bloomsbury Publishing|isbn=978-1-4081-3326-2|language=en}}</ref> The latter was generally preferred until 1906 when [[Einar Lönnberg]] established that ''A.{{nbsp}}platyrhynchos'' had priority, as it appeared on an earlier page in the text.<ref>{{cite journal | last=Johnsgard | first= Paul A. |author-link=Paul Johnsgard |title= Evolutionary relationships among the North American mallards.| journal= The Auk | volume=78| issue=1 |year=1961|pages= 3–43 [11–12] | url=http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1061&context=biosciornithology&sei-redir=1&referer=https%3A%2F%2Fscholar.google.com.au%2Fscholar?start%3D10%26q%3DAnas%2Bboschas%2Bplatyrhynchos%2BLinnaeus%26hl%3Den%26as_sdt%3D0,5#search="Anas_boschas_platyrhynchos_Linnaeus" | doi=10.2307/4082232| jstor= 4082232 | s2cid= 41605830 | doi-access=free | url-access=subscription }}</ref> The scientific name comes from [[Latin]] ''Anas'', "duck" and [[Ancient Greek]] πλατυρυγχος, ''platyrhynchus'', "broad-billed" (from πλατύς, ''platys'', "broad" and ρυγχός, ''rhunkhos'', "bill").<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/Helm_Dictionary_of_Scientific_Bird_Names_by_James_A._Jobling | publisher = Christopher Helm | isbn = 978-1-4081-2501-4 |pages = [https://archive.org/details/Helm_Dictionary_of_Scientific_Bird_Names_by_James_A._Jobling/page/n46 46], 309}}</ref> The [[genome]] of ''Anas platyrhynchos'' was sequenced in 2013.<ref name="Huang2013" />

The name ''mallard'' originally referred to any wild drake, and it is sometimes still used this way.<ref>{{citation|last=Magnus|first=PD|title=Scientific Enquiry and Natural Kinds: from Planets to Mallards|year=2012|publisher=Palgrave Macmillan|isbn=978-1-137-27125-9}}</ref> It was derived from the [[Old French]] ''{{lang|fr|malart}}'' or ''{{lang|fr|mallart}}'' for "wild drake" although its true derivation is unclear.<ref>{{Cite book|url=https://books.google.com/books?id=PD08AQAAMAAJ|title=The Athenaeum: A Journal of Literature, Science, the Fine Arts, Music, and the Drama|last1=Buckingham|first1=James Silk|last2=Sterling|first2=John|last3=Maurice|first3=Frederick Denison|last4=Stebbing|first4=Henry|last5=Dilke|first5=Charles Wentworth|last6=Hervey|first6=Thomas Kibble|last7=Dixon|first7=William Hepworth|last8=Maccoll|first8=Norman|last9=Rendall|first9=Vernon Horace|date=1904|publisher=J. Francis|language=en}}</ref> It may be related to, or at least influenced by, an [[Old High German]] masculine proper name ''{{lang|de|Madelhart}}'', clues lying in the alternative English forms "maudelard" and "mawdelard".<ref name="OED2" /> ''Masle'' (male) has also been proposed as an influence.<ref>{{Cite book|url=https://archive.org/details/adictionaryengl04unkngoog|title=Dictionary of English Etymology|last=Wedgwood|first=Hensleigh|date=1862|publisher=Trübner and Company|language=en}}</ref>

Mallards frequently interbreed with their closest relatives in the [[genus]] ''[[Anas]]'', such as the [[American black duck]], and also with species more distantly related, such as the [[northern pintail]], leading to various [[Hybrid (biology)|hybrid]]s that may be fully fertile.<ref name="Phillips" /> The mallard has hybridised with more than 40 species in the wild, and an additional 20 species in captivity,<ref>{{Cite book |last=McCarthy |first=Eugene M. |title=Handbook of Avian Hybrids of the World |publisher=Oxford University Press |year=2006 |isbn=978-0-19-518323-8 |location=New York, NY, US}}</ref> though fertile hybrids typically have two ''Anas'' parents.<ref>{{Cite journal |last=Johnsgard |first=Paul A. |date=1960 |title=Hybridization in the Anatide and its Taxonomic Implications |url=https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1070&context=biosciornithology |journal=Condor |volume=62 |issue=1 |pages=25–33|doi=10.2307/1365656 |jstor=1365656 }}</ref> Mallards and their domestic [[conspecific]]s are fully interfertile; many wild mallard populations in North America contain significant amounts of domestic mallard DNA.<ref>{{Cite journal |last1=Davis |first1=J. Brian |last2=Outlaw |first2=Diana C. |last3=Ringelman |first3=Kevin M. |last4=Kaminski |first4=Richard M. |last5=Lavretsky |first5=Philip |date=2022 |title=Low levels of hybridization between domestic and wild Mallards wintering in the lower Mississippi Flyway |journal=Ornithology |volume=139 |issue=4 |article-number=ukac034|doi=10.1093/ornithology/ukac034 |doi-access=free }}</ref><ref>{{Cite journal |last1=Schummer |first1=Michael L. |last2=Simpson |first2=John |last3=Shirkey |first3=Brendan |last4=Kucia |first4=Samuel R. |last5=Lavretsky |first5=Philip |last6=Tozer |first6=Douglas C. |date=2023 |title=Population genetics and geographic origins of mallards harvested in northwestern Ohio |journal=PLOS ONE |volume=18 |issue=3 |article-number=e0282874|doi=10.1371/journal.pone.0282874 |doi-access=free |pmid=36920978 |pmc=10016643 |bibcode=2023PLoSO..1882874S }}</ref>

Genetic analysis has shown that certain mallards appear to be closer to their [[Indo-Pacific]] relatives, while others are related to their American relatives.<ref name=johnson/> [[Mitochondrial DNA]] data for the [[D-loop replication|D-loop sequence]] suggest that mallards may have evolved in the general area of [[Siberia]]. Mallard bones rather abruptly appear in food remains of ancient humans and other deposits of [[fossil]] bones in [[Europe]], without a good candidate for a local predecessor [[species]].<ref name="Kulikova et al. 2005" /> The large [[Last Glacial Period|Ice Age]] [[Chronospecies|palaeosubspecies]] that made up at least the European and West Asian populations during the [[Pleistocene]] has been named ''Anas platyrhynchos palaeoboschas''.<ref>{{Cite book|url=https://books.google.com/books?id=G8Q-AQAAIAAJ|title=The Waterfowl of the World|last=Delacour|first=Jean|date=1964|publisher=Country Life|isbn=978-0-668-02970-4 |language=en}}</ref>{{Listen|filename=Mallard (Anas platyrhynchos) (W1CDR0001518 BD17).ogg|title=Call|description=A group of mallards quacking}}Mallards are differentiated in their mitochondrial DNA between North American and Eurasian populations,<ref name="Kraus2011" /> but the nuclear genome displays a notable lack of genetic structure.<ref name="Kraus2013" /> [[Haplotypes]] typical of American mallard relatives and [[eastern spot-billed duck]]s can be found in mallards around the [[Bering Sea]].<ref name="Kulikova et al. 2004" /> The [[Aleutian Islands]] hold a population of mallards that appear to be evolving towards becoming a [[subspecies]], as [[gene flow]] with other populations is very limited.<ref name="Kulikova et al. 2005" />

Also, the paucity of [[Morphology (biology)|morphological]] differences between the [[Old World]] mallards and the [[New World]] mallard demonstrates the extent to which the genome is shared among them such that birds like the [[eastern spot-billed duck]] are highly similar to the Old World mallard, and birds such as the Hawaiian duck are highly similar to the New World mallard.<ref name=":3">{{Cite journal|last1=Lavretsky|first1=Philip|last2=McCracken|first2=Kevin G.|last3=Peters|first3=Jeffrey L.|date=January 2014|title=Phylogenetics of a recent radiation in the mallards and allies (Aves: Anas): inferences from a genomic transect and the multispecies coalescent|url=https://www.researchgate.net/publication/256331063|journal=Molecular Phylogenetics and Evolution|volume=70|pages=402–411|doi=10.1016/j.ympev.2013.08.008|issn=1095-9513|pmid=23994490|bibcode=2014MolPE..70..402L }}</ref>

===Subspecies===
Two [[subspecies]] are currently accepted:<ref name="IOC">{{cite web | title=Screamers, ducks, geese, swans – IOC World Bird List | website=IOC World Bird List – Version 14.2 | date=2025-02-20 | url=https://www.worldbirdnames.org/new/bow/waterfowl/ | access-date=2025-09-10}}</ref>
{| class="wikitable"
|-
! Image !! Scientific name !! Distribution !! Characteristics
|-
|[[File:Anas platyrhynchos conboschas, Sisimiut, Greenland 1.jpg|120px]]<br />[[Sisimiut]], Greenland || ''A. p. conboschas''<br /><small>[[Christian Ludwig Brehm|C. L. Brehm]], 1831</small> || [[Greenland]], resident [[endemism|endemic]]. || Slightly larger, but with a smaller bill (an example of [[Bergmann's rule]]); paler plumage, and stockier body.
|-
|[[File:2015 Kaczka krzyżowka w wodzie (samiec) (tight crop).jpg|120px]]<br />[[Kłodzko]], Poland || ''A.&nbsp;p.&nbsp;platyrhynchos'' <br /> || Holarctic, except for Greenland. || The size of the nominate subspecies of mallard varies [[Cline (biology)|clinally]].<ref name=":11">{{Cite book|url=https://books.google.com/books?id=RT8qww1cyUMC&q=A.+p.+conboschas&pg=PA102|title=Wildfowl of the World|last1=Ogilvie|first1=M. A.|last2=Young|first2=Steve|date=2002|publisher=New Holland Publishers|isbn=978-1-84330-328-2|language=en}}{{Dead link|date=August 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> Note that [[domesticated duck]]s, although often cited as "A. p. domesticus", do ''not'' comprise a valid distinct subspecies; they are derived from within ''A. p. platyrhynchos''.
|-
|}

In the past, several other ducks, now treated as distinct species, were sometimes treated as subspecies of mallard:<ref name="HBW1">{{cite book | title=Handbook of the Birds of the World: Volume 1 Ostrich to Ducks | publisher=Lynx edicions | publication-place=Barcelona | date=1992 | isbn=84-87334-10-5 | pages=605–606}}</ref>
*[[Laysan duck]] ''Anas laysanensis''
*[[Hawaiian duck]] ''Anas wyvilliana''
*[[Mottled duck]] ''Anas fulvigula''
*[[American black duck]] ''Anas rubripes''
*[[Mexican duck]] ''Anas diazi''

==Description==
The mallard is a medium-sized waterfowl species that is often slightly heavier than most other dabbling ducks. It is {{convert|50|–|65|cm|in|abbr=on}} long{{snd}}of which the body makes up around two-thirds{{snd}}has a wingspan of {{convert|81|–|98|cm|in|abbr=on}},{{r|cramp|page=505}} and weighs {{convert|0.7|–|1.6|kg|lb|abbr=on}}.<ref name="CRC" /> Among standard measurements, the [[Wing chord (biology)|wing chord]] is {{convert|25.7|to|30.6|cm|in|abbr=on}}, the [[Beak|bill]] is {{convert|4.4|to|6.1|cm|in|abbr=on}}, and the [[Tarsus (skeleton)|tarsus]] is {{convert|4.1|to|4.8|cm|in|abbr=on}}.<ref name="Madge" />[[File:DrakeMallardPortrait.png|thumb|left|Adult drake mallard|220x220px]]The breeding male mallard is unmistakable, with a glossy bottle-green head and a white collar that demarcates the head and neck from the purple-tinged brown breast, grey-brown wings, and a pale grey belly.<ref>{{Cite book|url=https://books.google.com/books?id=RT8qww1cyUMC&q=mallard+bottle-green+white+collar&pg=PA102|title=Wildfowl of the World|last1=Ogilvie|first1=M. A.|last2=Young|first2=Steve|date=2002|publisher=New Holland Publishers|isbn=978-1-84330-328-2|language=en}}{{Dead link|date=August 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> The rear of the male is black, with white-bordered dark tail feathers.{{r|cramp|page=506}} The bill of the male is a yellowish-orange tipped with black, with that of the female generally darker and ranging from black to mottled orange and brown.<ref>{{Cite book|url=https://books.google.com/books?id=wG18DQAAQBAJ&q=mallard+bottle-green+white+collar&pg=PA22|title=Birds of Europe, North Africa, and the Middle East: A Photographic Guide|last1=Jiguet|first1=Frédéric|last2=Audevard|first2=Aurélien|date=21 March 2017|publisher=Princeton University Press|isbn=978-0-691-17243-9|language=en}}</ref> The female mallard is predominantly mottled, with each individual feather showing sharp contrast from buff to very dark brown, a coloration shared by most female dabbling ducks, and has buff cheeks, eyebrow, throat, and neck, with a darker crown and eye-stripe.{{r|cramp|page=506}} Mallards, like other [[Sexual dimorphism|sexually-dimorphic]] birds, can sometimes go though spontaneous sex reversal,<ref>{{Cite journal |last1=Rayner |first1=Enid |last2=Hamra |first2=Wayne |last3=Shipton |first3=Warren |date=2015 |title=Sexual Dimorphism and Sex Reversal in Birds |url=https://www.academia.edu/70676100 |journal=Journal of Applied Animal Science |volume=8 |issue=3 |pages=27–34}}</ref> often caused by damaged or nonfunctioning sex organs, such as the [[Ovary|ovaries]] in mallard hens.<ref>{{Cite journal |last1=Lavretsky |first1=Philip |last2=Hernandez |first2=Flor |last3=Davis |first3=Brian |date=2022 |title=Ovarian degeneration resulting in the phenotypic masculinisation of a wild female Mallard Anas platyrhynchos |url=https://wildfowl.wwt.org.uk/index.php/wildfowl/article/view/2777 |journal=Wildfowl |volume=72}}</ref> This phenomenon can cause female mallards to exhibit male plumage, and vice versa (phenotypic feminisation or masculinisation).

Both male and female mallards have distinct iridescent purple-blue speculum feathers edged with white, which are prominent in flight or at rest but temporarily shed during the annual summer moult.<ref name=":7">{{Cite book|url=https://books.google.com/books?id=T4gLRnplhVwC&q=mallard+eating+frog+google+book&pg=PA150|title=Wildlife of Pennsylvania and the Northeast|last1=Fergus|first1=Charles|last2=Hansen|first2=Amelia|date=2000|publisher=Stackpole Books|isbn=978-0-8117-2899-7|language=en}}</ref> Upon hatching, the plumage of the duckling is yellow on the underside and face (with streaks by the eyes) and black on the back (with some yellow spots) all the way to the top and back of the head.<ref name=":16">{{Cite book|url=https://books.google.com/books?id=FYbrCAAAQBAJ&q=mallard+the+plumage++duckling+is+yellow&pg=PA323|title=The inheritance of plumage colour in the common duck (Anas platyrhynchos linné)|last=Lancaster|first=Frank Maurice|date=17 December 2013|publisher=Springer|isbn=978-94-017-6834-4|language=en}}</ref> Its legs and bill are also black.<ref name=":16" /> As it nears a month in age, the duckling's plumage starts becoming drab, looking more like the female, though more streaked, and its legs lose their dark grey colouring.[[File:Anas Rubripes and Anas Platyrhynchos August 2008.JPG|thumb|An [[American black duck]] (upper left) and a male mallard (lower right) in eclipse plumage]]{{r|cramp|page=506}} Two months after hatching, the fledgling period has ended, and the duckling is now a juvenile.<ref>{{Cite book|url=https://books.google.com/books?id=e95PAAAAYAAJ|title=Annual Report|last=Station|first=Delta Waterfowl and Wetlands Research|date=1984|publisher=The Station|language=en}}</ref> The duckling is able to fly 50–60 days after hatching. Its bill soon loses its dark grey colouring, and its sex can finally be distinguished visually by three factors: 1){{nbsp}}the bill is yellow in males, but black and orange in females;<ref name=":12">{{Cite book|url=https://books.google.com/books?id=kU9XBQAAQBAJ&q=mallard+The+centre+tail+feather+is+curled+for+males+(called+a+drake+feather),+straight+for+females&pg=PT16|title=Daisy and Ducky Mallard|last=Moulton|first=Judy|date=7 November 2014|publisher=Xlibris Corporation|isbn=978-1-5035-1191-0|language=en}}{{self-published source|date=December 2017}}</ref> 2){{nbsp}}the breast feathers are reddish-brown in males, but brown in females;<ref name=":12" /> and 3){{nbsp}}in males, the centre tail feather (drake feather) is curled, but in females, the centre tail feather is straight.<ref name=":12" /> During the final period of maturity leading up to adulthood (6–10 months of age), the plumage of female juveniles remains the same while the plumage of male juveniles gradually changes to its characteristic colours.<ref name=":13">{{Cite book|url=https://books.google.com/books?id=9eHzAgAAQBAJ&q=mallard+plumage+of+female+juveniles&pg=PA51|title=The Helm Guide to Bird Identification|last=Vinicombe|first=Keith|date=27 March 2014|publisher=Bloomsbury Publishing|isbn=978-1-4729-0554-3|language=en}}</ref> This change in plumage also applies to adult mallard males when they transition in and out of their non-breeding [[eclipse plumage]] at the beginning and the end of the summer moulting period.<ref name=":13" /> The adulthood age for mallards is fourteen months, and the average life expectancy is three years, but they can live to twenty.<ref name="BTO" />

Several species of duck have brown-plumaged females that can be confused with the female mallard.<ref>{{Cite book|url=https://books.google.com/books?id=ToFfBL6e9zwC&q=mallard+Several+species+of+duck+have+brown-plumaged+females&pg=PA78|title=Attracting Birds to Your Garden|last1=Moss|first1=Stephen|last2=Cottridge|first2=David|date=2000|publisher=New Holland Publishers|isbn=978-1-85974-005-7|language=en}}{{Dead link|date=August 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> The female [[gadwall]] (''Mareca strepera'') has an orange-lined bill, white belly, black and white speculum that is seen as a white square on the wings in flight, and is a smaller bird.{{r|cramp|page=506}} More similar to the female mallard in [[North America]] are the American black duck (''A.{{nbsp}}rubripes''), which is notably darker-hued in both sexes than the mallard,<ref name=":17">{{Cite book|url=https://books.google.com/books?id=VEbX_iVqWrUC&q=mallard+More+similar+to+the+female+mallard+in+North+America+are+the+American+black+duck&pg=PA26|title=Kaufman Field Guide to Birds of North America|last=Kaufman|first=Kenn|date=2005|publisher=Houghton Mifflin Harcourt|isbn=978-0-618-57423-0|language=en}}</ref> and the [[mottled duck]] (''A.{{nbsp}}fulvigula''), which is somewhat darker than the female mallard, and with slightly different bare-part colouration and no white edge on the speculum.<ref name=":17" />

[[File:Female Mallard with faded plumage at Bray Lock, May 2015.JPG|thumb|left|Mallards are among the most common bird species to exhibit aberrant colouration, typically due to the influence of escaped domesticated ducks, more rarely to genetic mutations.<ref>{{Cite journal |last1=Abraham |first1=Kevin |last2=Risley |first2=Chris |last3=Weseloh |first3=D.V. Chip |date=2020 |title=Aberrant colouration in some Ontario birds |url=https://sora.unm.edu/sites/default/files/36-48%20OntBirds%20Apr%202020%2038-1b.pdf |journal=Ontario Birds |pages=36–48}}</ref> The female pictured here is [[Leucism|leucistic]]; leucism in birds often results in 'cream-coloured', 'apricot'<ref>{{Cite web |title=Apricot Mallard |url=https://chavezpark.org/apricot-mallard/ |website=Chavez Park Conservancy}}</ref> or muted feathers on certain parts of the body.<ref>{{Cite journal |last=van Grouw |first=Hein |date=2006 |title=Not every white bird is an albino: sense and nonsense about colour aberrations in birds |journal=Dutch Birding |volume=28 |pages=79–89}}</ref>]]
In captivity, domestic ducks come in wild-type plumages, white, and other colours.<ref name=":18">{{Cite book|url=https://books.google.com/books?id=njxEAAAAYAAJ&q=mallard+In+captivity,+domestic+ducks+come+in+wild-type+plumages,+white,+and+other+colours|title=The Encyclopaedia of Poultry|last=Hicks|first=James Stephen|date=1923|publisher=Waverley Book Company|language=en}}</ref> Most of these colour variants are also known in domestic mallards not bred as livestock, but kept as pets, [[aviary]] birds, etc., where they are rare but increasing in availability.<ref name=":18" />

A noisy species, the female has the deep ''quack'' stereotypically associated with ducks.{{r|cramp|page=507}} The female will often call with a sequence of 2–10 ''quacks'' in a row, starting loud and with the volume gradually decreasing.<ref>{{Cite web |title=Mallard Sounds, All About Birds, Cornell Lab of Ornithology |url=https://www.allaboutbirds.org/guide/Mallard/sounds |access-date=2024-04-20 |website=www.allaboutbirds.org |language=en}}</ref> Male mallards make a sound phonetically similar to that of the female, a typical ''quack'', but it is deeper and quieter compared to that of the female. Research conducted by Middlesex University on two English mallard populations found that the vocalisations of the mallard varies depending on their environment and have something akin to a [[Accent (sociolinguistics)|regional accent]], with urban mallards in [[London]] being much louder and more vociferous compared to rural mallards in [[Cornwall]], serving as an adaptation to persistent levels of anthropogenic noise.<ref>{{Cite news |date=2004-06-04 |title=Ducks 'quack in regional accents' |language=en-GB |url=http://news.bbc.co.uk/2/hi/uk_news/3775799.stm |access-date=2022-11-27}}</ref><ref>{{Cite web |last= |first= |date=2004-06-04 |title=Ducks quack in cockney, study finds |url=https://www.abc.net.au/science/articles/2004/06/04/1124782.htm |access-date=2022-11-27 |website=www.abc.net.au |language=en-AU}}</ref>

When [[Egg incubation|incubating]] a nest, or when offspring are present, females vocalise differently, making a call that sounds like a truncated version of the usual quack. This maternal vocalisation is highly attractive to their young. The repetition and [[Frequency|frequency modulation]] of these ''quacks'' form the auditory basis for [[Intra-species recognition|species identification]] in offspring, a process known as acoustic [[conspecific]] identification.<ref>{{Cite journal|last1=Dyer|first1=Antoinette B.|last2=Gottlieb|first2=Gilbert|date=1990|title=Auditory basis of maternal attachment in ducklings (Anas platyrhynchos) under simulated naturalistic imprinting conditions.|journal=Journal of Comparative Psychology|language=en|volume=104|issue=2|pages=190–194|doi=10.1037/0735-7036.104.2.190|pmid=2364664|issn=1939-2087}}</ref> In addition, females hiss if the nest or offspring are threatened or interfered with. When taking off, the wings of a mallard produce a characteristic faint whistling noise.<ref>{{Cite book|url=https://books.google.com/books?id=dXwPF_5IduIC|title=Life Histories of North American Wild Fowl|last=Bent|first=Arthur Cleveland|date=1962|publisher=Courier Corporation|isbn=978-0-486-25422-7|language=en}}</ref>

{{Multiple image
| image1            = Drake mallard flight (cropped).jpg
| image2            = Nova Scotia DSC 1316 (2278772065) (cropped 2).jpg
| total_width       = 200
| direction         = vertical
| footer            = Showing [[speculum feathers]]: <br />male (top) and female (bottom)
}}

The mallard is a rare example of both [[Allen's Rule]] and [[Bergmann's Rule]] in birds.<ref>{{Cite journal|last1=Salewski|first1=Volker|last2=Hochachka|first2=Wesley M.|last3=Fiedler|first3=Wolfgang|date=September 2009|title=Global warming and Bergmann's rule: do central European passerines adjust their body size to rising temperatures?|journal=Oecologia|volume=162|issue=1|pages=247–260|doi=10.1007/s00442-009-1446-2|issn=0029-8549|pmc=2776161|pmid=19722109}}</ref> Bergmann's Rule, which states that polar forms tend to be larger than related ones from warmer climates, has numerous examples in birds,<ref>{{Cite journal|author1-link=Matan Shelomi|last1=Shelomi|first1=Matan|last2=Zeuss|first2=Dirk|date=2017|title=Bergmann's and Allen's Rules in Native European and Mediterranean Phasmatodea|journal=Frontiers in Ecology and Evolution|language=en|volume=5|page=25 |doi=10.3389/fevo.2017.00025|bibcode=2017FrEEv...5...25S |issn=2296-701X|doi-access=free|hdl=11858/00-001M-0000-002C-DD87-4|hdl-access=free}}</ref> as in case of the Greenland mallard which is larger than the mallards further south.<ref name=":11" /> Allen's Rule says that appendages like ears tend to be smaller in polar forms to minimise heat loss, and larger in tropical and desert equivalents to facilitate heat diffusion, and that the polar taxa are stockier overall.<ref>{{Cite journal|last1=Bidau|first1=Claudio J.|last2=Martí|first2=Dardo A.|date=August 2008|title=A test of Allen's rule in ectotherms: the case of two south American Melanopline Grasshoppers (Orthoptera: Acrididae) with partially overlapping geographic ranges|journal=Neotropical Entomology|volume=37|issue=4|pages=370–380|doi=10.1590/S1519-566X2008000400004|pmid=18813738|issn=1519-566X|doi-access=free|hdl=11336/61319|hdl-access=free}}</ref> Examples of this rule in birds are rare as they lack external ears, but the bill of ducks is supplied with a few blood vessels to prevent heat loss,<ref>{{Cite book|url=https://books.google.com/books?id=kOdPAAAAYAAJ|title=Ducks Unlimited Magazine|publisher=Ducks Unlimited, Incorporated|year=2003|volume=67–68|page=62|language=en}}</ref> and, as in the Greenland mallard, the bill is smaller than that of birds farther south, illustrating the rule.<ref name=":11" />

Due to the variability of the mallard's genetic code, which gives it its vast interbreeding capability, mutations in the genes that decide plumage colour are very common and have resulted in a wide variety of hybrids, such as [[Brewer's duck]] (mallard × gadwall, ''Mareca strepera'').<ref name="Audubon" />

== Distribution and habitat ==

The mallard is widely distributed across the [[Northern Hemisphere|Northern]] and [[Southern Hemisphere|Southern]] Hemispheres; in North America its range extends from southern and central Alaska to Mexico, the [[Hawaiian Islands]],<ref name=":1">{{Cite book|url=https://books.google.com/books?id=gFawO8q9VfIC&q=mallard+southern+greenland&pg=PA212|title=Wildfowl|last=Madge|first=Steve|date=2010|publisher=A&C Black|isbn=978-1-4081-3895-3|page=212|language=en}}</ref> across the [[Palearctic]],<ref>{{Cite book|url=https://books.google.com/books?id=HVI3DQAAQBAJ|title=Birds of Seychelles|last1=Skerrett|first1=Adrian|last2=Disley|first2=Tony|date=2016|publisher=Bloomsbury Publishing|isbn=978-1-4729-4601-0|page=48|language=en}}</ref> from Iceland<ref name=":2">{{Cite book|url=https://books.google.com/books?id=yffUBAAAQBAJ&q=mallard+morocco&pg=PA219|title=Birds of the Strait of Gibraltar|last=Finlayson|first=Clive|date=2010|publisher=Bloomsbury Publishing|isbn=978-1-4081-3694-2|page=219|language=en}}</ref> and southern Greenland<ref name=":1" /> and parts of Morocco ([[North Africa]])<ref name=":2" /> in the west, [[Scandinavia]]<ref name=":2" /> and Britain<ref name=":2" /> to the north, and to Siberia,<ref>{{Cite book|url=https://books.google.com/books?id=JVpEDgAAQBAJ&q=mallard+siberia&pg=PA389|title=Bird Migration across the Himalayas: Wetland Functioning amidst Mountains and Glaciers|last1=Prins|first1=Herbert H. T.|last2=Namgail|first2=Tsewang|date=6 April 2017|publisher=Cambridge University Press|isbn=978-1-107-11471-5|language=en}}</ref> Japan,<ref name="Yamaguchi 875–881">{{Cite journal|last1=Yamaguchi|first1=Noriyuki|last2=Hiraoka|first2=Emiko|last3=Fujita|first3=Masaki|last4=Hijikata|first4=Naoya|last5=Ueta|first5=Mutsuyuki|last6=Takagi|first6=Kentaro|last7=Konno|first7=Satoshi|last8=Okuyama|first8=Miwa|last9=Watanabe|first9=Yuki|date=September 2008|title=Spring migration routes of mallards (Anas platyrhynchos) that winter in Japan, determined from satellite telemetry|journal=Zoological Science|volume=25|issue=9|pages=875–881|doi=10.2108/zsj.25.875|issn=0289-0003|pmid=19267595|s2cid=23445791|doi-access=free}}</ref> and South Korea.<ref name="Yamaguchi 875–881" /> Also in the east, it ranges to south-eastern and south-western Australia<ref>{{Cite book|url=https://books.google.com/books?id=_BjSBAAAQBAJ|title=Naturalised Birds of the World|last=Lever|first=Christopher|date=2010|publisher=Bloomsbury Publishing|isbn=978-1-4081-3312-5|page=89|language=en}}</ref> and New Zealand<ref>{{Cite book|url=https://books.google.com/books?id=_BjSBAAAQBAJ&pg=PA89|title=Naturalised Birds of the World|last=Lever|first=Christopher|date=2010|publisher=Bloomsbury Publishing|isbn=978-1-4081-3312-5|page=89|language=en}}</ref> in the Southern hemisphere.{{r|cramp|page=505}}<ref name="IUCN" /> It is strongly [[bird migration|migratory]] in the northern parts of its breeding range, and winters farther south.<ref>{{Cite book|url=https://books.google.com/books?id=gas8AAAAIAAJ|title=International Wildfowl Inquiry Volume i Factors Affecting the General Status of Wild Geese and Wild Duck|last=Anonymous|publisher=Cambridge University Press|language=en}}</ref><ref>{{Cite book|url=https://books.google.com/books?id=GFP1a2Qo9DoC|title=Habitat Management for Migrating and Wintering Waterfowl in North America|last1=Smith|first1=Loren M.|last2=Pederson|first2=Roger L.|last3=Kaminski|first3=Richard M.|date=1989|publisher=Texas Tech University Press|isbn=978-0-89672-204-0|language=en}}</ref> For example, in North America, it winters south to the [[southern United States]] and [[northern Mexico]],<ref>{{Cite book|url=https://books.google.com/books?id=ILrZ4fhHnGcC|title=Final environmental statement for the issuance of annual regulations permitting the sport hunting of migratory birds|last=Service|first=U. S. Fish and Wildlife|date=1975|publisher=U.S. Dept. of the Interior, U.S. Fish & Wildlife Service|language=en}}</ref><ref>{{Cite book|url=https://books.google.com/books?id=0mHW6i4e9QIC|title=The Laguna Madre of Texas and Tamaulipas|last1=Tunnell|first1=John Wesley|last2=Judd|first2=Frank W.|date=2002|publisher=Texas A&M University Press|isbn=978-1-58544-133-4|page=180|language=en}}</ref> but also regularly strays into [[Central America]] and the [[Caribbean]] between September and May.<ref>{{Cite book|url=https://books.google.com/books?id=3tKAfqxkFAIC|title=Westwood Lake Chronicles|last=Winkler|first=Lawrence|date=2012|publisher=Lawrence Winkler|isbn=978-0-9916941-0-5|language=en}}</ref> A drake later named "Trevor" attracted media attention in 2018 when it turned up on the island of [[Niue]], an atypical location for mallards.<ref>{{cite news |last=Mulligan |first=Jesse |date=6 September 2018 |title=The loneliest duck in Niue |url=https://www.radionz.co.nz/national/programmes/afternoons/audio/2018661388/the-loneliest-duck-in-niue |work=[[Radio New Zealand]] |access-date=29 January 2019 }}</ref><ref>{{cite news |last=Lyons |first=Kate |date=7 September 2018 |title=Trevor the lonely duck gets tiny island of Niue in a flap|url=https://www.theguardian.com/world/2018/sep/07/trevor-the-lonely-duck-gets-tiny-island-of-niue-in-a-flap |work=[[The Guardian]] |access-date=29 January 2019 }}</ref>

The mallard inhabits a wide range of habitats and climates, from the Arctic tundra to subtropical regions.<ref>{{Cite book|url=https://books.google.com/books?id=xNQgAQAAIAAJ|title=People and Wildlife in Northern North America: Essays in Honor of R. Dale Guthrie|last=Guthrie|first=Russell Dale|date=2001|publisher=Archaeopress|isbn=978-1-84171-236-9|language=en}}</ref> It is found in both fresh- and salt-water wetlands, including parks, small ponds, rivers, lakes and [[Estuary|estuaries]], as well as shallow inlets and open sea within sight of the coastline.<ref>{{Cite book|url=https://books.google.com/books?id=wWQw11SLvVwC&q=mallard+arctic+tundra&pg=PA1525|title=International Wildlife Encyclopedia: Leopard – marten|last1=Burton|first1=Maurice|last2=Burton|first2=Robert|date=2002|publisher=Marshall Cavendish|isbn=978-0-7614-7277-3|page=1525|language=en}}</ref> Water depths of less than {{convert|0.9|m|ft}} are preferred, with birds avoiding areas more than a few metres deep.<ref>{{cite web|url=http://www.elmwoodparkzoo.org/animal-mallard-duck.php|title=Mallard Duck • Elmwood Park Zoo {{!}} Elmwood Park Zoo {{!}} www.elmwoodparkzoo.org|date=2015|website=www.elmwoodparkzoo.org|archive-url=https://web.archive.org/web/20170218090853/http://www.elmwoodparkzoo.org/animal-mallard-duck.php|archive-date=18 February 2017|access-date=19 June 2017}}</ref> They are attracted to bodies of water with aquatic vegetation.{{r|cramp|page=507}}<!-- cites previous three sentences -->

==Behaviour==
[[File:Drake mallard Anas platyrhynchos performing the grunt-whistle 2.jpg|thumb|Drake mallard performing the grunt-whistle<ref name="Abraham74" />]]

===Feeding===
The mallard is omnivorous and very flexible in its choice of food.<ref>{{Cite journal|last1=van Toor|first1=Mariëlle L.|last2=Hedenström|first2=Anders|last3=Waldenström|first3=Jonas|last4=Fiedler|first4=Wolfgang|last5=Holland|first5=Richard A.|last6=Thorup|first6=Kasper|last7=Wikelski|first7=Martin|date=30 August 2013|title=Flexibility of Continental Navigation and Migration in European Mallards|journal=PLOS ONE|volume=8|issue=8|doi=10.1371/journal.pone.0072629|issn=1932-6203|pmc=3758317|pmid=24023629|article-number=e72629|bibcode=2013PLoSO...872629V|doi-access=free}}</ref> Its diet may vary based on several factors, including the stage of the breeding cycle, short-term variations in available food, [[nutrient]] availability, and [[Interspecific competition|interspecific]] and [[intraspecific competition]].<ref name="Krapu" /> The majority of the mallard's diet seems to be made up of [[gastropod]]s,<ref name=":14">{{Cite book|url=https://books.google.com/books?id=fnkZBQAAQBAJ&q=mallard+diet+gastropod&pg=PA410|title=Ducks, Geese, and Swans of North America|last=Baldassarre|first=Guy A.|date=2014|publisher=Johns Hopkins University Press|isbn=978-1-4214-0751-7|page=410|language=en}}</ref> [[insect]]s (including beetles, flies, [[lepidoptera]]ns, [[Dragonfly|dragonflies]], and [[Caddisfly|caddisflies]]),<ref>{{Cite journal|last=Eldridge|first=Jan|date=1990|title=Waterfowl Management Handbook|url=https://www.nwrc.usgs.gov/wdb/pub/wmh/13_3_3.pdf|journal=Fish and Wildlife Leaflet}}</ref> [[crustacean]]s,<ref name=":15">{{Cite book|url=https://books.google.com/books?id=PGSSr19ez0kC&q=Mallards+usually+form+pairs+(in+October+and+November+in+the+Northern+hemisphere)&pg=PA102|title=Wildlife of the Mid-Atlantic: A Complete Reference Manual|last=Rappole|first=John H.|date=2012|publisher=University of Pennsylvania Press|isbn=978-0-8122-2201-2|page=102|language=en}}</ref> other [[arthropod]]s,<ref>{{cite web | url=https://animaldiversity.org/accounts/Anas_platyrhynchos/ | title=''Anas platyrhynchos'' (Mallard) | website=[[Animal Diversity Web]] }}</ref> worms,<ref name=":14" /> [[feces]] of other birds,<ref name=BOW>{{cite journal | url=https://birdsoftheworld.org/bow/species/mallar3/cur/foodhabits | title=Mallard (Anas platyrhynchos), version 1.0 | journal=Birds of the World | date=8 May 2024 | last1=Drilling | first1=Nancy | last2=Titman | first2=Rodger D. | last3=McKinney | first3=Frank }}</ref> many varieties of seeds and plant matter,<ref name=":14" /> and roots and [[tuber]]s.<ref name=":15" /> During the breeding season, male birds were recorded to have eaten 37.6% animal matter and 62.4% plant matter, most notably the grass ''[[Echinochloa crus-galli]]'', and nonlaying females ate 37.0% animal matter and 63.0% plant matter, while laying females ate 71.9% animal matter and only 28.1% plant matter.<ref name="Swanson" /> Plants generally make up the larger part of a bird's diet, especially during autumn migration and in the winter.<ref name="Gruenhagen" /><ref name="Combs" />

The mallard usually feeds by dabbling for plant food or grazing; there are reports of it eating [[frog]]s, other [[amphibian]]s, and [[fish]], including [[Carrion|carcass]]es.<ref name=":6">{{Cite book|url=https://books.google.com/books?id=Z6Rf3otGNdUC&q=mallard+eating+frog+google+book&pg=PA60|title=Birds of Ontario: Habitat Requirements, Limiting Factors, and Status: Volume 1–Nonpasserines: Loons through Cranes|last=Sandilands|first=Al|date=2011|publisher=University of British Columbia Press|isbn=978-0-7748-5943-1|page=60|language=en}}</ref><ref name=BOW/> However, in 2017 a flock of mallards in Romania were observed hunting fledglings of small migratory birds when they land in the water, which included a [[grey wagtail]] and a [[black redstart]]. This was the first documented occasion they had been seen attacking and consuming large vertebrates.<ref>{{cite web |url=https://www.bbc.co.uk/news/science-environment-40445379 |title=Wild ducks caught on camera snacking on small birds |last=Briggs |first=Helen |date=30 June 2017 |website=BBC News |publisher=BBC |access-date=30 June 2017 }}</ref> It usually nests on a river bank, but not always near water. It is highly gregarious outside of the breeding season and forms large [[Flock (birds)|flock]]s, which are known as "sordes".<ref>{{Cite book|last=Lipton|first=James|url=https://archive.org/details/exaltationoflark0000lipt_x7z9|url-access=registration|title=An Exaltation of Larks|date=1991|publisher=Viking|isbn=978-0-670-30044-0|language=en}}</ref><gallery mode="packed" heights="140">
File:Mallard duck eating bread.jpg|Eating bread
File:Fish-Eating Mallard.jpg|Eating a small fish
File:Duck eating a Fish (5979923772).jpg|Eating a larger fish
File:Mallard drake eating leopard frog Sand Lake WMD (14822335555).jpg|Eating a frog
</gallery>

===Breeding===
Mallards usually form pairs (in October and November in the Northern Hemisphere) until the female lays eggs at the start of the nesting season, which is around the beginning of spring.<ref>{{Cite book|url=https://books.google.com/books?id=RsrV3uOZKN4C|title=The Encyclopedia of Birds|last=Anonymous|date=2005|publisher=Parragon Publishing India|isbn=978-1-4054-9851-7|page=50|language=en}}</ref> At this time she is left by the male who joins up with other males to await the moulting period, which begins in June (in the Northern Hemisphere).<ref>{{Cite book|url=https://books.google.com/books?id=Sd9FAAAAYAAJ&q=mallard+moulting+period|title=Moult in birds|last1=Ginn|first1=H. B.|last2=Melville|first2=Dorothy Sutherland|date=1983|publisher=British Trust for Ornithology|isbn=978-0-903793-02-5|language=en}}</ref><ref>{{Cite book|url=https://books.google.com/books?id=4htx09cb-6gC&q=mallard++moulting+period+which+begins+in+June&pg=PA359|title=Waterbirds Around the World: A Global Overview of the Conservation, Management and Research of the World's Waterbird Flyways|last1=Boere|first1=G. C.|last2=Galbraith|first2=Colin A.|last3=Stroud|first3=David A.|date=2006|publisher=The Stationery Office|isbn=978-0-11-497333-9|language=en}}</ref> During the brief time before this, however, the males are still sexually potent and some of them either remain on standby to sire replacement [[Clutch (eggs)|clutch]]es (for female mallards that have lost or abandoned their previous clutch)<ref name=":20">{{Cite book|url=https://books.google.com/books?id=4htx09cb-6gC&q=mallard++moulting+period+which+begins+in+June&pg=PA359|title=Waterbirds Around the World: A Global Overview of the Conservation, Management and Research of the World's Waterbird Flyways|last1=Boere|first1=G. C.|last2=Galbraith|first2=Colin A.|last3=Stroud|first3=David A.|date=2006|publisher=The Stationery Office|isbn=978-0-11-497333-9|page=359|language=en}}</ref> or forcibly mate with females that appear to be isolated or unattached regardless of their species and whether or not they have a brood of ducklings.<ref name=":20" /><ref>{{Cite book|url=https://books.google.com/books?id=jUUKN77Ko_0C&q=mallard+forcibly+mate+with+females&pg=PA130|title=Field Guide to Urban Wildlife|last=Feinstein|first=Julie|date=2011|publisher=Stackpole Books|isbn=978-0-8117-0585-1|page=130|language=en}}</ref><gallery mode="packed" heights="80" caption="Growth series (from youngest to oldest)">
File:Anas platyrhynchos MWNH 1048.JPG|Egg
File:Mallard and ducklings - geograph.org.uk - 4473798.jpg|Young ducklings
File:Mallard ducklings (3752889877).jpg|Older ducklings
File:Duckling in Central Park (81320).jpg|Moulting
File:Anas platyrhynchos juvenile JdP 2013-06-14 n01 retusche.jpg|Fledgling female and male
File:Female Mallard IMG 1434.jpg|Adult female
</gallery>

Nesting sites are typically on the ground, hidden in vegetation where the female's speckled plumage serves as effective [[camouflage]],<ref>{{cite web|date=2020-03-29|title=The secret life of mallard ducks|url=https://scottishwildlifetrust.org.uk/2020/03/the-secret-life-of-mallard-ducks/|access-date=2021-04-20|website=Scottish Wildlife Trust|language=en-GB}}</ref> but female mallards have also been known to nest in hollows in trees, boathouses, roof gardens and on balconies, sometimes resulting in hatched offspring having difficulty following their parent to water.<ref>{{cite web|title=Nesting mallards|url=https://www.rspb.org.uk/makeahomeforwildlife/advice/helpingbirdstest/nestingmallards/|access-date=2021-04-20|website=The RSPB|language=en-GB}}</ref> [[File:Duckling (47016759604).jpg|thumb|Duckling]] 
[[File:20250709 mallard duckling wethersfield cove PD208385 1.jpg|thumb|Swimming duckling]]
[[File:Canard colvert femelle et ses petits (Lac Archambeault, Qc).webm|thumb|Female mallard with five ducklings]]Egg clutches number 8–13 creamy white to greenish-buff eggs free of speckles.<ref name=":24">{{Cite book|url=https://books.google.com/books?id=wWQw11SLvVwC&q=mallard+50+days+to+fledling&pg=PA1525|title=International Wildlife Encyclopedia: Leopard – marten|last1=Burton|first1=Maurice|last2=Burton|first2=Robert|date=2002|publisher=Marshall Cavendish|isbn=978-0-7614-7277-3|language=en|access-date=16 June 2016}}</ref><ref name="Hauber2014">{{cite book|url=https://books.google.com/books?id=evQvBAAAQBAJ|title=The Book of Eggs: A Life-Size Guide to the Eggs of Six Hundred of the World's Bird Species|last=Hauber|first=Mark E.|date=2014|publisher=University of Chicago Press|isbn=978-0-226-05781-1|page=83}}</ref> They measure about {{convert|58|mm|in|abbr=on}} in length and {{convert|32|mm|in|abbr=on}} in width.<ref name="Hauber2014" /> The eggs are laid on alternate days, and [[Incubation period|incubation]] begins when the clutch is almost complete.<ref name="Hauber2014" /> Incubation takes 27–28{{nbsp}}days and [[Fledge|fledging]] takes 50–60{{nbsp}}days.<ref name=":24" /><ref>{{Cite book|url=https://books.google.com/books?id=cYDOY6DszoIC&q=mallard+The+nesting+period+clutch+is+8%E2%80%9313+eggs&pg=PA131|title=The Illustrated Encyclopedia of Birds|last1=DK|last2=International|first2=BirdLife|date=1 March 2011|publisher=Dorling Kindersley Limited|isbn=978-1-4053-3616-1|language=en}}</ref> The ducklings are [[precocial]] and fully capable of swimming as soon as they hatch.<ref>{{cite news|url=https://audubonportland.org/our-work/rehabilitate-wildlife/having-a-wildlife-problem/urban-mallards/#:~:text=Mallard%20ducklings%20are%20precocial%2C%20meaning,own%20within%20minutes%20of%20hatching.&text=She%20will%20typically%20lead%20them,her%20for%2042%2D60%20days |title=Urban Mallards - Portland Audubon |newspaper=Portland Audubon |publisher=Audubonportland.org |date= |access-date=2022-03-16}}</ref> However, [[Imprinting (psychology)|filial imprinting]] compels them to instinctively stay near the mother, not only for warmth and protection but also to learn about and remember their habitat as well as how and where to forage for food.<ref>{{Cite book|url=https://books.google.com/books?id=W9bBCwAAQBAJ&q=mallard+mother+warmth+protection+forage+food&pg=PA51|title=British Columbia: Graced by Nature's Palette|last=Townsley|first=Frank|date=10 March 2016|publisher=FriesenPress|isbn=978-1-4602-7773-7|language=en}}</ref> Though adoptions are known to occur, female mallards typically do not tolerate stray ducklings near their broods, and will violently attack and drive away any unfamiliar young, sometimes going as far as to kill them.<ref>{{cite web|title=Mallard Ducklings {{!}} Nesting Ducks|url=https://www.rspb.org.uk/birds-and-wildlife/advice/how-you-can-help-birds/where-do-ducks-nest/mallard-ducklings/|access-date=2021-10-09|website=The RSPB|language=en-GB}}</ref>

When ducklings mature into flight-capable juveniles, they learn about and remember their traditional migratory routes (unless they are born and raised in captivity). In New Zealand, where mallards are [[Naturalisation (biology)|naturalised]], the nesting season has been found to be longer; eggs and clutches are larger and nest survival is generally greater compared with mallards in their native range.<ref>{{cite journal |author1= Sheppard, J.L. |author2= Amundson, C.L. | author3= Arnold, T.W. | author4= Klee, D. | year=2019| title= Nesting ecology of a naturalized population of Mallards Anas platyrhynchos in New Zealand| journal=Ibis| volume=161| pages=  504–520| doi= 10.1111/ibi.12656| issue=3|bibcode= 2019Ibis..161..504S |s2cid= 91988206 }}</ref>

In cases where a nest or brood fails, some mallards may mate for a second time in an attempt to raise a second clutch, typically around early-to-mid summer. In addition, mallards may occasionally breed during the autumn in cases of unseasonably warm weather; one such instance of a 'late' clutch occurred in November 2011, in which a female successfully hatched and raised a clutch of eleven ducklings at the [[WWT London Wetland Centre|London Wetland Centre]].<ref>{{Cite news|date=2011-11-20|title=Ducklings hatch at London Wetland Centre|language=en-GB|work=BBC News|url=https://www.bbc.com/news/uk-england-london-15809760|access-date=2021-05-24}}</ref>
During the breeding season, both male and female mallards can become aggressive, driving off competitors to themselves or their mate by charging at them.<ref>{{Cite book|url=https://books.google.com/books?id=c3brsyiAJ0wC&q=mallard+breeding+season+male+female+mallards+aggressive&pg=PA66|title=Man and Wildfowl|last=Kear|first=Janet|date=30 November 2010|publisher=Bloomsbury Publishing|isbn=978-1-4081-3760-4|language=en}}</ref> Males tend to fight more than females and attack each other by repeatedly pecking at their rival's chest, ripping out feathers and even skin on rare occasions. Female mallards are also known to carry out 'inciting displays', which encourage other ducks in the flock to begin fighting.<ref>{{Cite journal|last=Cunningham|first=Emma J. A.|date=2003-05-01|title=Female mate preferences and subsequent resistance to copulation in the mallard|url=https://academic.oup.com/beheco/article/14/3/326/257579|journal=Behavioral Ecology|language=en|volume=14|issue=3|pages=326–333|doi=10.1093/beheco/14.3.326|issn=1045-2249|doi-access=free}}</ref> It is possible that this behaviour allows the female to evaluate the strength of potential partners.<ref>{{cite web|url=https://web.stanford.edu/group/stanfordbirds/text/essays/Duck_Displays.html|title=Duck Displays|website=web.stanford.edu|access-date=2020-02-22}}</ref>

The drakes that end up being left out after the others have paired off with mating partners sometimes target an isolated female duck, even one of a different species, and proceed to chase and peck at her until she weakens, at which point the males take turns copulating with the female.<ref name=":10">{{Cite journal|last=Moeliker|first=Cornelis|date=2001|title=The first case of homosexual necrophilia in the mallard Anas platyrhynchos (Aves:Anatidae)|url=http://www.hetnatuurhistorisch.nl/fileadmin/user_upload/documents-nmr/Persberichten/Persberichten/persberichten_2013/DSA8_243-248.pdf|journal=Deinsea 8|pages=243–248}}</ref> Lebret (1961) calls this behaviour "Attempted Rape Flight", and [[Stanley Cramp]] and K.E.L. Simmons (1977) speak of "rape-intent flights".<ref name=":10" /> Male mallards also occasionally chase other male ducks of a different species, and even each other, in the same way.<ref name=":10" /> In one documented case of "homosexual necrophilia", a male mallard copulated with another male he was chasing after the chased male died upon flying into a glass window.<ref name=":10" /> This paper was awarded an [[Ig Nobel Prize]] in 2003.<ref>{{Cite book|url=https://books.google.com/books?id=wCrxAAAAMAAJ|title=Annals of Improbable Research|date=2005|publisher=MIT Museum|language=en}}</ref>

Mallards are opportunistically targeted by [[brood parasite]]s, occasionally having eggs laid in their nests by [[Redhead (duck)|redhead]]s, [[ruddy duck]]s, [[lesser scaup]], [[gadwall]]s, [[northern shoveller]]s, [[northern pintail]]s, [[cinnamon teal]], [[common goldeneye]]s, and other mallards.<ref>{{Cite book|url=https://books.google.com/books?id=wvpPMwEACAAJ|title=Ducks, Geese, and Swans of North America|last=Baldassarre|first=Guy A.|date=2014|publisher=JHU Press|isbn=978-1-4214-0751-7|language=en}}</ref> These eggs are generally accepted when they resemble the eggs of the host mallard, but the hen may attempt to eject them or even abandon the nest if parasitism occurs during egg laying.<ref name=BNA/>

==Predators and threats==
[[File:Mute Swan attacking Mallard Family (7617017146).jpg|thumb|A male [[mute swan]] (''Cygnus olor'') driving off a female mallard.]]
In addition to human hunting, mallards of all ages (but especially young ones) and in all locations must contend with a wide diversity of predators including [[Bird of prey|raptor]]s and [[owl]]s, [[Mustelidae|mustelid]]s, [[Corvidae|corvid]]s, [[snake]]s, [[raccoon]]s, [[opossum]]s, [[skunk]]s, [[turtle]]s, large [[fish]], [[Felidae|felid]]s, and [[Canidae|canid]]s, the last two including domestic cats and dogs.<ref>{{Cite journal|last=Martz|first=Gerald F.|date=1967|title=Effects of nesting cover removal on breeding puddle ducks|journal=Journal of Wildlife Management|volume=31|issue=2|pages=236–247|doi=10.2307/3798312|jstor=3798312}}</ref> The most prolific natural predators of adult mallards are [[red fox]]es (''Vulpes vulpes''; which most often pick off brooding females) and the faster or larger birds of prey, (e.g. [[peregrine falcon]]s, ''[[Aquila (genus)|Aquila]]'' or ''[[Haliaeetus]]'' eagles).<ref name="NPWRC" /> In North America, adult mallards face no fewer than 15 species of birds of prey, from [[northern harrier]]s (''Circus hudsonius'') and [[short-eared owl]]s (''Asio flammeus'') (both smaller than a mallard) to huge [[Bald eagle|bald]] (''Haliaeetus leucocephalus'') and [[golden eagle]]s (''Aquila chrysaetos''), and about a dozen species of mammalian predators, not counting several more avian and mammalian predators who threaten eggs and nestlings.<ref name=BNA/>

Mallards are also preyed upon by other waterside [[apex predator]]s, such as [[grey heron]]s (''Ardea cinerea''),<ref>{{Cite journal|last1=Marquiss|first1=M.|last2=Leitch|first2=A. F.|date=1 October 1990|title=The diet of Grey Herons Ardea cinerea breeding at Loch Leven, Scotland, and the importance of their predation on ducklings|journal=Ibis|language=en|volume=132|issue=4|pages=535–549|doi=10.1111/j.1474-919X.1990.tb00277.x|issn=1474-919X}}</ref> [[great blue heron]]s (''Ardea herodias'') and [[black-crowned night heron]]s (''Nycticorax nycticorax''), the [[European herring gull]] (''Larus argentatus''), the [[wels catfish]] (''Silurus glanis''), and the [[northern pike]] (''Esox lucius'').<ref>{{Cite book|url=https://books.google.com/books?id=X1l0cl6_DzAC&q=mallard+preyed+Northern+pike|title=Reader's Digest Scenic wonders of Canada: an illustrated guide to our natural splendors|date=1976|publisher=Reader's Digest Association (Canada)|isbn=978-0-88850-049-6|language=en}}</ref> Crows (''[[Corvus (genus)|Corvus]]''{{nbsp}}{{Abbr|spp.|species}}) are also known to kill ducklings and adults on occasion.<ref>{{Cite book|url=https://books.google.com/books?id=CuX1f28Kg-EC&q=crows+eating+mallards&pg=PA140|title=Ecosystem Matters: Activity and Resource Guide for Environmental Educators|last=Adams|first=Mary|date=October 1995|publisher=DIANE Publishing|isbn=978-0-7881-2453-2|language=en}}</ref> Also, mallards may be attacked by larger anseriformes such as [[swan]]s (''[[Cygnus (genus)|Cygnus]]''{{nbsp}}{{Abbr|spp.|species}}) and [[geese]] during the breeding season, and are frequently driven off by these birds over territorial disputes. [[Mute swan]]s (''Cygnus olor'') have been known to attack or even kill mallards if they feel that the ducks pose a threat to their offspring.<ref>{{Cite book|url=https://books.google.com/books?id=sBfSBAAAQBAJ&q=mallard+Mute+swans+drown+offspring&pg=PA52|title=The Birds of Leicestershire and Rutland|last1=Fray|first1=Rob|last2=Davies|first2=Roger|last3=Gamble|first3=Dave|last4=Harrop|first4=Andrew|last5=Lister|first5=Steve|date=30 June 2010|publisher=Bloomsbury Publishing|isbn=978-1-4081-3311-8|language=en}}</ref> [[Common loon]]s (''Gavia inmer'') are similarly territorial and aggressive towards other birds in such disputes, and will frequently drive mallards away from their territory.<ref>{{cite web|last=Sperry|first=Mark L.|title=Common Loon Attacks on Waterfowl|url=https://sora.unm.edu/sites/default/files/journals/jfo/v058n02/p0201-p0205.pdf|publisher=Minnesota Department of Natural Resources, Wetland Wildlife Populations and Research Group}}</ref> However, in 2019, a pair of common loons in Wisconsin were observed raising a mallard duckling for several weeks, having seemingly adopted the bird after it had been abandoned by its parents.<ref>{{cite web|date=2019-07-12|title=A Mallard Duckling Is Thriving—and Maybe Diving—Under the Care of Loon Parents|url=https://www.audubon.org/news/a-mallard-duckling-thriving-and-maybe-diving-under-care-loon-parents|access-date=2021-10-09|website=Audubon|language=en}}</ref>

In summer, a combination of hot temperatures and reduced water levels place mallards at an increased risk of contracting [[botulism]], as these conditions are ideal for ''[[Clostridium botulinum]]'' to propagate, with the birds also more likely to come into contact with [[botulinum toxin]] produced by the bacteria. Outbreaks of botulism among mallard populations can lead to mass die-offs.<ref>{{Cite web |title=Mallard |url=https://wildlifeillinois.org/identify-wildlife/mallard/ |access-date=2024-06-13 |website=Wildlife Illinois |language=en-US}}</ref>

The predation-avoidance behaviour of sleeping with one eye open, allowing one brain hemisphere to remain aware while the other half sleeps, was first demonstrated in mallards, although it is believed to be widespread among birds in general.<ref>{{Cite journal|last=Niels C.|first=Rattenborg|date=1999|title=Half-awake to the risk of predation|journal=Nature|volume=397|issue=6718|pages=397–398|doi=10.1038/17037|pmid=29667967|bibcode=1999Natur.397..397R|s2cid=4427166}}</ref>

== Status and conservation ==
[[File:Mallards pond 2009.ogv|thumb|thumbtime=1|Several drakes swimming in a pond]]
[[File:Mallard - Gräsand (Anas platyrhynchos) - Ystad-2024.ogg|thumb|A mallard (male) eats rolled oats from the hand.]]
Since 1998, the mallard has been rated as a species of [[least concern]] on the [[IUCN Red List of Endangered Species]]. This is because it has a large range–more than {{cvt|20000000|km2}}<ref>{{cite web | url=http://maps.iucnredlist.org/map.html?id=22680186 | title=IUCN Red List maps | access-date=26 March 2018 | archive-date=5 March 2024 | archive-url=https://web.archive.org/web/20240305124118/http://maps.iucnredlist.org/map.html?id=22680186 }}</ref> and because its population is increasing. Also, the population size of the mallard is very large.<ref name="IUCN"/>

Unlike many waterfowl, mallards have benefited from human alterations to the world{{snd}}so much so that they are now considered an [[invasive species]] in some regions.<ref name=":8">{{Cite journal|last1=Mooney|first1=H. A.|last2=Cleland|first2=E. E.|date=8 May 2001|title=The evolutionary impact of invasive species|journal=Proceedings of the National Academy of Sciences|language=en|volume=98|issue=10|pages=5446–5451|doi=10.1073/pnas.091093398|issn=0027-8424|pmc=33232|pmid=11344292|bibcode=2001PNAS...98.5446M|doi-access=free}}</ref> They are a common sight in urban parks, lakes, ponds, and other human-made water features in the regions they inhabit, and are often tolerated or encouraged in human habitat due to their placid nature towards humans, their ducklings and their beautiful and iridescent colours.<ref name=":7" /> While most are not domesticated, mallards are so successful at coexisting in human regions that the main conservation risk they pose comes from the loss of genetic diversity among a region's traditional ducks once humans and mallards colonise an area. Mallards are very adaptable, being able to live and even thrive in urban areas which may have supported more localised, sensitive species of waterfowl before development.<ref>{{Cite book|url=https://books.google.com/books?id=sH0KH-JLlmkC&q=Mallard+very+adaptable+able+to+live+in+urban+areas|title=A Guide to Urban Wildlife Management|last1=Leedy|first1=Daniel L.|last2=Adams|first2=Lowell W.|date=1984|publisher=National Institute for Urban Wildlife|language=en}}</ref> The release of [[Feral animal|feral]] mallards in areas where they are not native sometimes creates problems through interbreeding with indigenous [[waterfowl]].<ref name=":8" /><ref name=":9" /> These non-migratory mallards interbreed with indigenous wild ducks from local populations of closely related species through [[genetic pollution]] by producing fertile offspring.<ref name=":9" /> Complete hybridisation of various species of wild duck gene pools could result in the extinction of many indigenous waterfowl.<ref name=":9">{{cite web |url=https://pubs.usgs.gov/fs/2007/3047/fs2007-3047.pdf |title=Hawaiian Duck's Future Threatened by Feral Mallards |last1=Uyehara |first1=Kimberly |last2=Engilis |first2=Andrew |last3=Reynolds |first3=Michelle |editor-last=Hendley |editor-first=James |archive-url=https://web.archive.org/web/20170504072645/https://pubs.usgs.gov/fs/2007/3047/fs2007-3047.pdf |archive-date=4 May 2017 |access-date=19 June 2017}}</ref> The mallard itself is the ancestor of most domestic ducks, and its naturally evolved wild gene pool gets genetically polluted in turn by the domestic and feral populations.<ref>{{cite web|url=https://www.eagletimes.com/lifestyles/of-a-feather-why-this-duck/article_8f380da9-88be-5d03-a423-40815a5b7270.html|title=Of a Feather: Why this duck?|website=The Eagle Times|date=23 October 2021 }}</ref>
Over time, a continuum of hybrids ranging between almost typical examples of either species develop; the [[speciation]] process is beginning to reverse itself.<ref name="Rhymer06" /> This has created [[Conservation biology|conservation]] concerns for relatives of the mallard, such as the [[Hawaiian duck]],<ref name="Rhymer96" /><ref name="Griffin" /> the New Zealand grey duck (''A.{{nbsp}}s. superciliosa)'' subspecies of the [[Pacific black duck]],<ref name="Rhymer96" /><ref name="Williams" /> the American black duck,<ref name="Avise" /><ref name="Mank" /> the [[mottled duck]],<ref name="McCracken" /> [[Meller's duck]],<ref name="Young" /> the [[yellow-billed duck]],<ref name="Rhymer06" /> and the [[Mexican duck]],<ref name="Rhymer96" /><ref name="McCracken" /> in the latter case even leading to a dispute as to whether these birds should be considered a species<ref name="AOU" /> (and thus entitled to more conservation research and funding) or included in the mallard species. Ecological changes and hunting have also led to a decline of local species; for example, the New Zealand grey duck population declined drastically due to overhunting in the mid-20th century.<ref name="Williams" /> Hybrid offspring of Hawaiian ducks seem to be less well adapted to native habitat, and using them in re-introduction projects apparently reduces success.<ref name="Rhymer96" /><ref name="Kirby" /> In summary, the problems of mallards "hybridising away" relatives is more a consequence of local ducks declining than of mallards spreading; [[allopatric speciation]] and isolating behaviour have produced today's diversity of mallard-like ducks despite the fact that, in most, if not all, of these populations, hybridisation must have occurred to some extent.<ref>{{Cite journal |last1=Tubaro |first1=Pablo L. |last2=Lijtmaer |first2=Dario A. |date=1 October 2002 |title=Hybridization patterns and the evolution of reproductive isolation in ducks |journal=Biological Journal of the Linnean Society |language=en |volume=77 |issue=2 |pages=193–200 |doi=10.1046/j.1095-8312.2002.00096.x |issn=0024-4066|doi-access=free |hdl=11336/136485 |hdl-access=free }}</ref><gallery mode="packed" heights="100" caption="Mallard hybrids">
File:Wood Duck × Mallard imported from iNaturalist photo 182462006 on 3 December 2024.jpg|''x [[Wood duck|Aix sponsa]]''
File:Mallard × Muscovy Duck imported from iNaturalist photo 355013753 on 3 December 2024.jpg|''x [[Muscovy duck|Cairina moschata]]''
File:Mallard × American Wigeon imported from iNaturalist photo 27284228 on 3 December 2024.jpg|''x [[American wigeon|Mareca americana]]''
File:Brewer's Duck imported from iNaturalist photo 364753928 on 3 December 2024 (cropped).jpg|''x [[Gadwall|Mareca strepera]]'' ([[Brewer's duck]])
File:Mallard × Eurasian Wigeon imported from iNaturalist photo 450807057 on 3 December 2024.jpg|''x [[Eurasian wigeon|Mareca penelope]]''
File:Mallard × Red-crested Pochard imported from iNaturalist photo 423714582 on 3 December 2024.jpg|''x [[Red-crested pochard|Netta rufina]]''
File:Mallard × Ruddy Shelduck imported from iNaturalist photo 356571403 on 3 December 2024 (cropped).jpg|''x [[Ruddy shelduck|Tadorna ferruginea]]''
File:Mallard × Northern Pintail imported from iNaturalist photo 26297743 on 3 December 2024 (cropped).jpg|''x [[Northern pintail|A. acuta]]''
File:Hybrid Anas carolinensis × Anas platyrhynchos, Dallas, Texas.jpg|''x [[Green-winged teal|A. carolinensis]]''
File:Mallard × Mexican Duck imported from iNaturalist photo 351774358 on 3 December 2024.jpg|''x [[Mexican duck|A. diazi]]''
File:Mallard × Mottled Duck imported from iNaturalist photo 111437277 on 3 December 2024 (cropped).png|''x [[Mottled duck|A. fulvigula]]''
File:Pacific Black Duck × Mallard imported from iNaturalist photo 324966462 on 3 December 2024.jpg|''x [[Pacific black duck|A. superciliosa]]''
File:American Black Duck × Mallard imported from iNaturalist photo 249600327 on 3 December 2024.jpg|''x [[American black duck|A. rubripes]]''
File:Mallard × Yellow-billed Duck imported from iNaturalist photo 251718983 on 3 December 2024 (cropped).jpg|''x [[Yellow-billed duck|A. undulata]]''
File:Mallard × Eastern Spot-billed Duck imported from iNaturalist photo 251491647 on 3 December 2024 (cropped).jpg|''x [[Eastern spot-billed duck|A. zonorhyncha]]''
</gallery>

=== Invasiveness ===
[[File:Anas platyrhynchos oustaleti last male.jpg|thumb|The last male [[Mariana mallard]]]] Mallards are causing severe "genetic pollution" to South Africa's [[biodiversity]] by breeding with endemic ducks<ref name="krugerpark.co.za" /> even though the ''[[Agreement on the Conservation of African-Eurasian Migratory Waterbirds]] – ''an agreement to protect the local waterfowl populations – applies to the mallard as well as other ducks.<ref>{{cite web |url=https://pca-cpa.org/wp-content/uploads/sites/175/2016/11/Agreement-on-the-Conservation-of-African-Eurasian-Migratory-Waterbirds.pdf|title=Agreement on the Conservation of African-Eurasian Migratory Waterbirds |website=Official Journal of the European Union |archive-url=https://web.archive.org/web/20170619111955/https://pca-cpa.org/wp-content/uploads/sites/175/2016/11/Agreement-on-the-Conservation-of-African-Eurasian-Migratory-Waterbirds.pdf |archive-date=19 June 2017 |access-date=19 June 2017}}</ref> The hybrids of mallards and the yellow-billed duck are fertile, capable of producing hybrid offspring.<ref name=":4">{{cite web |url=http://www.mdga.co.za/code/environment/feb2011.html |title=Marina da Gama |date=2007 |website=www.mdga.co.za |archive-url=https://web.archive.org/web/20170211171037/http://mdga.co.za/code/environment/feb2011.html|archive-date=11 February 2017 |access-date=19 June 2017}}</ref> If this continues, only hybrids occur and in the long term result in the extinction of various indigenous waterfowl.<ref name=":4" /> The mallard can crossbreed with 63&nbsp;other species, posing a severe threat to indigenous waterfowl's genetic integrity.<ref>{{Cite news |url=http://sanquentinnews.com/those-mighty-mallards-can-bust-the-speed-limit/ |title=Those mighty mallards can bust the speed limit |last=Marsh |first=David |date=1 June 2010 |work=San Quentin News |access-date=19 June 2017 |archive-url=https://web.archive.org/web/20170615200616/http://sanquentinnews.com/those-mighty-mallards-can-bust-the-speed-limit/ |archive-date=15 June 2017 |language=en-US}}</ref> Mallards and their hybrids compete with indigenous birds for resources, including nest sites, roosting sites, and food.<ref name=krugerpark.co.za/>
Availability of mallards, mallard ducklings, and fertilised mallard eggs for public sale and private ownership, either as poultry or as pets, is currently legal in the United States, except for the state of [[Florida]], which has currently banned domestic ownership of mallards. This is to prevent hybridisation with the native [[mottled duck]].<ref name=myfwc2/>

The mallard is considered an invasive species in Australia and New Zealand,{{r|cramp|page=505}} where it competes with the [[Pacific black duck]] (known as the grey duck locally in New Zealand) which was over-hunted in the past. There, and elsewhere, mallards are spreading with increasing [[urbanisation]] and hybridising with local relatives.<ref name="Rhymer96" />

The eastern or [[Chinese spot-billed duck]] is currently introgressing into the mallard populations of the [[Primorsky Krai]], possibly due to [[Habitat (ecology)|habitat]] changes from [[global warming]].<ref name="Kulikova et al. 2004" /> The Mariana mallard was a resident [[allopatric]] population – in most respects a good species – apparently initially derived from mallard-Pacific black duck hybrids;<ref name=Yamashina/> it became [[extinct]] in the late 20th century.<ref name=MadgeWildfowl>{{Cite book |title=Wildfowl |last1=Madge |first1=Steve |author-link1=Steve Madge |last2=Burn |first2=Hilary |author-link2=Hilary Burn |year=2010 |orig-date=1989 |publisher=Christopher Helm Publications |isbn=978-1-4081-3895-3 |page=211 |url=https://books.google.com/books?id=gFawO8q9VfIC&pg=PA211}}</ref>

The [[Laysan duck]] is an insular relative of the mallard, with a very small and fluctuating population.<ref>{{cite journal |last1=Browne |first1=Robert |last2=Griffin |first2=Curtice |last3=Chang |first3=Paul |last4=Hubley |first4=Mark |last5=Martin |first5=Amy |date=1993 |title=Genetic Divergence Among Populations of the Hawaiian Duck, Laysan Duck, and Mallard |journal=The Auk |volume=110 |issue=1 |pages=49–56 |jstor=4088230}}</ref><ref name="IUCN" /> Mallards sometimes arrive on its island home during migration, and can be expected to occasionally have remained and hybridised with Laysan ducks as long as these species have existed.<ref>{{cite web |url=https://www.fws.gov/pacific/ecoservices/documents/LaysanDuckRRP/LaysanDuckRRPChap2.html |title=Recovery Strategy – Laysan Duck Revised Recovery Plan |date=September 2009 |website=www.fws.gov |archive-url=https://web.archive.org/web/20170620234655/https://www.fws.gov/pacific/ecoservices/documents/LaysanDuckRRP/LaysanDuckRRPChap2.html |archive-date=20 June 2017 |access-date=19 June 2017}}</ref> However, these hybrids are less well adapted to the peculiar ecological conditions of [[Laysan Island]] than the local ducks, and thus have lower [[Fitness (biology)|fitness]]. Laysan ducks were found throughout the Hawaiian archipelago before 400{{nbsp}}AD, after which they suffered a rapid decline during the Polynesian colonisation.<ref name=":21">{{cite web |url=http://animaldiversity.org/accounts/Anas_laysanensis/ |title=Anas laysanensis (Laysan duck) |last1=Myers |first1=P. |last2=Espinosa |first2=R. |date=2016 |website=Animal Diversity Web |language=en |archive-url=https://web.archive.org/web/20160313053719/http://animaldiversity.org/accounts/Anas_laysanensis/ |archive-date=13 March 2016 |access-date=19 June 2017 |last3=Parr |first3=C. S. |last4=Jones |first4=T. |last5=Hammond |first5=G. S. |last6=Dewey |first6=T. A.}}</ref> Now, their range includes only Laysan Island.<ref name=":21" /> It is one of the successfully translocated birds, after having become nearly extinct in the early 20th century.<ref>{{cite book |url=https://books.google.com/books?id=RttCNJzMUEEC&q=laysan+duck+translocated&pg=PA8 |article=Clostridium Infections |title=Advances in Research and Treatment |edition=2011 |date=9 January 2012 |publisher=ScholarlyEditions |isbn=978-1-4649-6013-0 |language=en}}</ref>

== Relationship with humans ==
{{further|Domestic duck}}
=== Domestication ===
[[File:Anas platyrhynchos domesticus 001.jpg|thumb|An [[American Pekin|American Pekin duck]], a breed of [[domestic duck]] derived from the mallard]]
Mallards have often been ubiquitous in their regions among the ponds, rivers, and streams of human parks, farms, and other human-made waterways{{snd}}even to the point of visiting water features in human [[courtyard]]s.<ref>{{Cite book|url=https://books.google.com/books?id=kfgyAQAAMAAJ&q=mallard+rivers+ponds&pg=PA118-IA19|title=Channel Improvements, Columbia and Lower Willamette River Federal Navigation Channel, (OR, WA): Environmental Impact Statement|date=1999}}</ref>

Mallards have had a long relationship with humans. Almost all [[domestic duck]] breeds derive from the mallard, with the exception of a few [[Muscovy duck|Muscovy]] breeds,<ref>{{Cite book|url=https://books.google.com/books?id=hW6BCwAAQBAJ&pg=PA9|title=Poultry Behaviour and Welfare|last1=Appleby|first1=Michael C.|last2=Mench|first2=Joy A.|last3=Hughes|first3=Barry O.|date=2004|publisher=CABI|isbn=978-0-85199-667-7}}</ref> and are listed under the [[Trinomial nomenclature|trinomial name]] ''A. p. domesticus''. Mallards are generally [[Monogamy in animals|monogamous]] while domestic ducks are mostly [[Animal sexual behaviour#Polygamy|polygamous]]. Domestic ducks have no territorial behaviour and are less aggressive than mallards.<ref name=":23">{{Cite book|url=https://books.google.com/books?id=AQ89AAAAIAAJ&pg=PA407|title=The Agrarian History of England and Wales: Volume 1, Part 1, Prehistory|last1=Piggott|first1=Stuart|last2=Thirsk|first2=Joan|date=2 April 1981|publisher=CUP Archive|isbn=978-0-521-08741-4}}</ref> Domestic ducks are mostly kept for meat; their eggs are also eaten, and have a strong flavour.<ref name=":23" /> They were first domesticated in [[Southeast Asia]] at least 4,000 years ago, during the [[Neolithic|Neolithic Age]], and were also farmed by the [[Demography of the Roman Empire|Roman]]s in Europe, and the [[Malays (ethnic group)|Malays]] in [[Asia]].<ref>{{Cite book |url=https://books.google.com/books?id=MfrdBcKd79wC&pg=PA7|title=Ducks, Geese and Swans: General chapters, species accounts (Anhima to Salvadorina) |last=Kear|first=Janet |date=2005 |publisher=Oxford University Press |isbn=978-0-198-61008-3 }}</ref> As the domestic duck and the mallard are the same species as each other, it is common for mallards to mate with domestic ducks and produce hybrid offspring that are fully fertile.<ref name=":22">{{Cite book |url=https://books.google.com/books?id=xtEGCAAAQBAJ&pg=PT212|title=Elements of Ethology: A textbook for agricultural and veterinary students|last=Wood-Gush|first=D.|date=6 December 2012|publisher=Springer Science & Business Media |isbn=978-94-009-5931-6}}</ref> Because of this, mallards have been found to contain genes of the domestic duck.<ref name=":22" />

While the keeping of domestic breeds is more popular, pure-bred mallards are sometimes kept for eggs and meat,<ref>{{cite web|url=http://duckhobby.com/raising-mallard-ducks-how-to-raise-mallards-in-your-backyard-duck-yard/|archive-url=https://web.archive.org/web/20180216113254/http://duckhobby.com/raising-mallard-ducks-how-to-raise-mallards-in-your-backyard-duck-yard/|archive-date=16 February 2018|title=Raising Mallard Ducks: How to Raise Mallards In Your Backyard Duck Yard – DuckHobby.com|language=en-US|access-date=2019-05-03}}</ref> although they may require wing clipping to restrict flying.

=== Hunting ===
{{further|Waterfowl hunting}}
[[File:Nature_Mort_-_Hen_and_Drake_Mallard.jpg|thumb|[[George Hetzel]], mallard [[still life]] painting, 1883–1884]]
Mallards are one of the most common [[species]] shot in [[waterfowl hunting]] due to their large [[population]] size. The ideal location for hunting mallards is considered to be where the water level is somewhat shallow where the birds can be found foraging for food.<ref>{{Cite book|url=https://books.google.com/books?id=cmFClEqEY0kC&pg=PA108|title=Field & Stream|last=O'Neill|first=Michael J.|date=February 1973|publisher=Columbia Broadcasting System Publications|volume=77|page=108|issue=10}}</ref> Hunting mallards might cause the population to decline in some places, at some times, and with some populations.<ref>{{Cite book|url=https://books.google.com/books?id=nTM3AQAAMAAJ&pg=PA90|title=Cape Cod National Seashore (N.S.), Hunting Program: Environmental Impact Statement|date=2007|page=90}}</ref> In certain countries, the mallard may be legally shot but is protected under national acts and policies. For example, in the United Kingdom, the mallard is protected under the [[Wildlife and Countryside Act 1981]], which restricts certain hunting methods or taking or killing mallards.<ref>{{Cite book|title=Tips for Pheasant Shooting from some of the Finest Hunters|last=Walsingham|first=Lord|publisher=Read Books Ltd|year=2016|isbn=978-1-4733-5705-1}}</ref>

=== Mallard-vehicle collisions ===
{{Further|Bird strike}}
Since standardized data collection began in 1990, the United States [[Federal Aviation Administration]] has recorded 1320 mallard collisions with aircraft, 261 of which caused damage to the craft (through 2022).<ref name=":0">{{Cite book |last1=Dolbeer |first1=Richard A. |url=https://www.faa.gov/sites/faa.gov/files/Wildlife-Strike-Report-1990-2022.pdf |title=Wildlife Strikes to Civil Aircraft in the United States, 1990 - 2022 |last2=Begier |first2=Michael J. |last3=Miller |first3=Phyllis R. |last4=Weller |first4=John R. |last5=Anderson |first5=Amy L. |publisher=Federal Aviation Administration |year=2023 |edition=29th |location=Washington, D.C., USA |page=55}}</ref> In the United States, the mallard ranks as the 7th most hazardous bird to both military and commercial aircraft.<ref>{{Cite journal |last1=Pfeiffer |first1=Morgan B. |last2=Blackwell |first2=Bradley F. |last3=DeVault |first3=Travis L. |date=2018 |title=Quantification of avian hazards to military aircraft and implications for wildlife management |journal=PLOS ONE |volume=13 |issue=11 |article-number=e0206599 |doi=10.1371/journal.pone.0206599|doi-access=free |pmid=30383828 |pmc=6211720 |bibcode=2018PLoSO..1306599P }}</ref><ref>{{Cite journal |last1=DeVault |first1=Travis L. |last2=Blackwell |first2=Bradley F. |last3=Seamans |first3=Thomas W. |last4=Begier |first4=Michael J. |last5=Kougher |first5=Jason D. |last6=Washburn |first6=Jenny E. |last7=Miller |first7=Phyllis R. |last8=Dolbeer |first8=Richard A. |date=2018 |title=Estimating interspecific economic risk of bird strikes with aircraft |journal=Wildlife Society Bulletin |volume=42 |issue=1 |pages=94–101 |doi=10.1002/wsb.859|bibcode=2018WSBu...42...94D }}</ref> Mallards are of particular concern due to their ubiquity; they are widespread and adaptable to urban environments.<ref>{{Cite journal |last1=Figley |first1=William K. |last2=VanDruff |first2=Larry W. |date=1982 |title=The ecology of urban mallards |journal=Wildlife Monographs |volume=81 |issue=81 |pages=3–39|jstor=3830665 }}</ref><ref name=":5">{{Cite journal |last1=Guenin |first1=Shane |last2=Pakula |first2=Carson J. |last3=Skaggs |first3=Jonathon |last4=Fernandez-Juricic |first4=Esteban |last5=DeVault |first5=Travis |date=2024 |title=Inefficacy of mallard flight responses to approaching vehicles |journal=PeerJ |volume=12 |article-number=e18124 |doi=10.7717/peerj.18124|doi-access=free |pmid=39346053 |pmc=11438428 }}</ref> Mallards also generally fail to avoid approaching vehicles in experimental settings, especially at high vehicle speeds.<ref name=":5" />

Though most [[bird strike]]s occur during the takeoff and landing phases of flight,<ref name=":0" /> at least one mallard has been struck at cruising altitude (21,000 feet).<ref>{{Cite journal |last=Manville |first=Richard H. |date=1963 |title=Altitude record for mallard |url=https://sora.unm.edu/sites/default/files/journals/wilson/v075n01/p0092-p0092.pdf |journal=The Wilson Bulletin |volume=75 |issue=1 |page=92}}</ref>

=== As food ===
Since ancient times, the mallard has been eaten as food. The wild mallard was eaten in [[Neolithic Greece]].<ref>{{Cite book|url=https://books.google.com/books?id=KdR4jRJCxEsC&pg=PA124|title=Food in the Ancient World from A to Z|last=Dalby|first=Andrew|date=15 April 2013|publisher=Routledge|isbn=978-1-135-95422-2}}</ref> Usually, only the breast and thigh meat is eaten.<ref>{{Cite book|url=https://books.google.com/books?id=TOG-ItIHp_kC&pg=PA584|title=The Visual Food Encyclopedia|date=1996|publisher=Québec Amerique|isbn=978-2-7644-0898-8}}</ref> It does not need to be [[Hanging (meat)|hung]] before preparation, and is often braised or roasted, sometimes flavoured with [[bitter orange]] or with [[Port (wine)|port]].<ref>{{Cite book|url=https://books.google.com/books?id=pZ-1AQAAQBAJ&pg=PT1722|title=The Oxford Companion to Food|last=Davidson|first=Alan|date=2006|publisher=Oxford University Press|isbn=978-0-19-101825-1|page=472|language=en}}</ref>

=== In culture ===

''[[Make Way for Ducklings]]'' is a [[Children's book|children's picture book]] written and illustrated by [[Robert McCloskey]]. The book centers on a pair of mallards who raise their ducklings in the [[Boston Public Garden]].<ref>{{Cite book |title=Make way for ducklings |date=1988 |publisher=The Viking Press |isbn=978-0-670-45149-4 |editor-last=McCloskey |editor-first=Robert |edition=45. [pr.] |location=New York}}</ref>

''[[Migration (2023 film)|Migration]]'' is an animated [[Adventure film|adventure]] [[comedy film]] produced by [[Universal Pictures]] and [[Illumination (company)|Illumination]]. The story follows a family of mallards who try to migrate from [[New England]] to [[Jamaica]].<ref>{{Cite web |date=2023-10-26 |title=Migration |url=https://www.uphe.com/movies/migration |access-date=2024-07-30 |website=www.uphe.com |language=en}}</ref>

[[Trevor (duck)|The world's loneliest duck]], named "Trevor" by locals after New Zealand politician [[Trevor Mallard]], appeared without explanation on the Pacific island of [[Niue]], dying there in 2019.
{{clear}}

== Footnotes ==
{{noteslist}}

== References ==
{{Reflist|refs=
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<ref name=Kraus2013>{{cite journal |last1=Kraus |first1=R.H.S. |last2=van Hooft |first2=P. |last3=Megens |first3=H.-J. |last4=Tsvey |first4=A. |last5=Fokin |first5=S.Y. |last6=Ydenberg |first6=Ronald C. |last7=Prins |first7=Herbert H.T. |year= 2013 |title=Global lack of flyway structure in a cosmopolitan bird revealed by a genome wide survey of single nucleotide polymorphisms |journal=Molecular Ecology |publication-date=January 2013 |volume=22 |issue=1 |pages=41–55 |doi=10.1111/mec.12098 |pmid= 23110616|bibcode=2013MolEc..22...41K |s2cid=11190535 }}</ref>

<ref name=krugerpark.co.za>{{cite web |url=http://www.krugerpark.co.za/krugerpark-times-3-6-bird-threat-22588.html |title=Invasive Alien Bird Species Pose A Threat, Kruger National Park, Siyabona Africa Travel (Pty) Ltd – South Africa Safari Travel Specialist |date=2008 |website=krugerpark.co.za |archive-url=https://web.archive.org/web/20161112125241/http://www.krugerpark.co.za/krugerpark-times-3-6-bird-threat-22588.html |archive-date=12 November 2016 |access-date=23 August 2012 }}</ref>

<ref name="Kulikova et al. 2004">{{cite journal |last1=Kulikova |first1=Irina V. |last2=Zhuravlev |first2=Yury N. |last3=McCracken |first3=Kevin G. |year=2004 |title=Asymmetric hybridization and sex-biased gene flow between Eastern Spot-billed Ducks (''Anas zonorhyncha'') and Mallards (''A. platyrhynchos'') in the Russian Far East |journal=[[The Auk]] |volume=121 |issue=3 |pages=930–949 |doi=10.1642/0004-8038(2004)121[0930:AHASGF]2.0.CO;2 |s2cid=17470882 |doi-access=free }}</ref>

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<ref name=Moeliker>{{cite journal |last=Moeliker |first=C. W. |author-link=Kees Moeliker |year=2001 |title=The first case of homosexual necrophilia in the Mallard ''Anas platyrhynchos'' (Aves: Anatidae) |journal=Deinsea |volume=8 |issue=243–247 |url=http://www.hetnatuurhistorisch.nl/fileadmin/user_upload/documents-nmr/Persberichten/Persberichten/persberichten_2013/DSA8_243-248.pdf |format=PDF}}</ref>

<ref name=Myfwc>{{cite web |url=http://myfwc.com/duck/mottled/theproblem.htm |title=Mottled Ducks: The Problem: Hybridization; Florida Fish and Wildlife Conservation Commission |publisher=[[Florida Fish and Wildlife Conservation Commission]] |access-date=23 August 2012 |archive-url=https://web.archive.org/web/20060420042916/http://www.myfwc.com/duck/mottled/theproblem.htm |archive-date=20 April 2006}}</ref>{{Failed verification|date=September 2014}}-->

<ref name=myfwc2>{{cite web |title=Mallard Possession Rule |url=http://myfwc.com/wildlifehabitats/managed/waterfowl/mallard-possession-rule/ |publisher=[[Florida Fish and Wildlife Conservation Commission]] |archive-url=https://web.archive.org/web/20161018210055/http://myfwc.com/wildlifehabitats/managed/waterfowl/mallard-possession-rule |archive-date=18 October 2016 |date=10 July 2004 |access-date=10 February 2015}}</ref>

<ref name=NPWRC>{{cite web |url=http://www.npwrc.usgs.gov/resource/mammals/sexratio/revised.htm |title=Impact of Red Fox Predation on the Sex Ratio of Prairie Mallards |publisher=USGS Northern Prairie Wildlife Research Center |date=3 August 2006 |archive-url=https://web.archive.org/web/20150102043957/http://www.npwrc.usgs.gov/resource/mammals/sexratio/revised.htm |archive-date=2 January 2015 |access-date=23 August 2012}}</ref>

<ref name=OED2>{{cite OED2|mallard}}</ref>
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<ref name=Phillips>{{cite journal |last=Phillips |first=John C. |year=1915 |title= Experimental studies of hybridization among ducks and pheasants |journal=[[Journal of Experimental Zoology]] |volume=18 |issue=1 |pages=69–112 |doi=10.1002/jez.1400180103|bibcode=1915JEZ....18...69P |url=https://zenodo.org/record/1426870 }}</ref>

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<ref name=Williams>{{cite journal |author1=Williams, Murray |author2=Basse, Britta |year=2006 |title=Indigenous gray ducks, ''Anas superciliosa'', and introduced mallards, ''A. platyrhynchos'', in New Zealand: processes and outcome of a deliberate encounter |journal=Acta Zoologica Sinica |volume=52 |issue=Supplement |pages=579–582 |url=http://www.actazool.org/temp/%7B819A6F5F-484C-4938-AB7D-F6B2EB691E47%7D.pdf }}</ref>

<ref name=Yamashina>{{cite journal |last1=Yamashina |first1=Y. |year=1948 |title=Notes on the Marianas mallard |journal=[[Pacific Science]] |volume=2 |pages=121–124 }}</ref>

<!--unused<ref name="genetic tools 2012">{{cite journal | title = Fifty-nine microsatellite markers for hybrid classification studies involving endemic Florida Mottled Duck (Anas fulvigula fulvigula) and invasive Mallards (A. platyrhynchos) | journal = Conservation Genetics Resources | last1 = Seyoum | first1 = S | last2 = Tringali | first2 = MD | last3 = Bielefeld | first3 = RR | last4 = Feddersen | first4 = JC | last5 = Benedict Jr | first5 = RJ | last6 = Fanning | first6 = AT | last7 = Barthel | first7 = B | last8 = Curtis | first8 = C | last9 = Puchulutegui | first9 = C | last10 = Roberts | first10 = ACM | last11 = Villanova Jr | first11 = VL | last12 = Tucker | first12 = EC | date = 2012 | volume = 4 | issue = 3 | doi = 10.1007/s12686-012-9622-9 | pages=681–687}}</ref>-->

<ref name=Young>{{cite journal |last1=Young |first1=H. Glyn |last2=Rhymer |first2=Judith M. |year=1998 |title=Meller's duck: A threatened species receives recognition at last |journal =Biodiversity and Conservation |volume=7 |issue=10 |pages=1313–1323 |doi=10.1023/A:1008843815676|bibcode=1998BiCon...7.1313Y |s2cid=27384967 }}</ref>

<ref name=Abraham74>{{cite journal |last1=Abraham |first1=Richard L. |date=1 October 1974 |title=Vocalizations of the Mallard (Anas Platyrhynchos) |url=https://pdfs.semanticscholar.org/3d5a/3eac46816a6baf5ccfcdab728a7c80abc701.pdf |archive-url=https://web.archive.org/web/20190217030230/https://pdfs.semanticscholar.org/3d5a/3eac46816a6baf5ccfcdab728a7c80abc701.pdf |archive-date=17 February 2019 |access-date=2019-02-15 |journal=The Condor: Ornithological Applications |volume=76 |issue=4 |pages=401–420 |doi=10.2307/1365814  |jstor=1365814 |s2cid=2319728 }}</ref>

}}

== External links ==
{{Commons category|Anas platyrhynchos}}
{{Wikispecies|Anas platyrhynchos}}
* {{InternetBirdCollection|mallard-anas-platyrhynchos}}
* {{VIREO|Mallard}}

{{English Game|state=collapse}}
{{North American Game|state=collapse}}

{{Taxonbar|from=Q25348}}
{{Authority control}}

[[Category:Anas]]
[[Category:Birds described in 1758]]
[[Category:Ducks]]
[[Category:Migratory birds (Eastern Hemisphere)]]
[[Category:Migratory birds (Western Hemisphere)]]
[[Category:Holarctic birds]]
[[Category:Game birds]]
[[Category:Articles containing video clips]]
[[Category:Native birds of the Eastern United States]]
[[Category:Animal taxa named by Carl Linnaeus]]
[[Category:Extant Pleistocene first appearances]]
[[Category:Birds of the United States]]
[[Category:Least concern biota of the United States]]