Mergus

{{Short description|Genus of birds}} {{Redirect|Merganser|the white merganser|Smew|other meanings|Merganser (disambiguation)}} {{Automatic taxobox | name = Typical mergansers | image = Mergus serrator M F Toronto.JPG | image_caption = Red-breasted merganser (''Mergus serrator'') | taxon = Mergus | authority = Linnaeus, 1758 | type_species = ''Mergus serrator'' | type_species_authority = Linnaeus, 1758 | subdivision_ranks = Species | subdivision = {{dagger}}''Mergus australis'' Auckland Island merganser ''Mergus merganser'' Common merganser {{dagger}}''Mergus milleneri'' Chatham merganser ''Mergus octosetaceus'' Brazilian merganser ''Mergus serrator'' Red-breasted merganser ''Mergus squamatus'' Scaly-sided merganser }}

'''''Mergus''''' is the genus containing the '''typical mergansers''' ({{IPAc-en|m|ɜːr|ˈ|ɡ|æ|n|s|ər|z}} {{respell|mur|GAN|sərz}}),<ref>{{Cite book|title=The Chambers Dictionary|publisher=Chambers|year=2003|isbn=0-550-10105-5|edition=9th|chapter=merganser}}</ref> fish-eating ducks in the subfamily Anatinae.

The common merganser or goosander (''Mergus merganser'') and red-breasted merganser (''M. serrator'') have broad ranges in the northern hemisphere. The Brazilian merganser (''M. octosetaceus'') is a South American duck, and one of the six most threatened waterfowl in the world, with possibly fewer than 250 birds in the wild. The scaly-sided merganser or "Chinese merganser" (''M. squamatus'') is also an endangered species; it lives in temperate eastern Asia, breeding in the northeast and wintering further south.

The hooded merganser (''Lophodytes cucullatus'', formerly known as ''Mergus cucullatus'') is not currently included in this genus but is closely related, and may be embedded within it.<ref name="Buckner">{{Cite journal|author1=Janet C. Buckner |author2=Ryan Ellingson |author3=David A. Gold |author4=Terry L. Jones |author5=David K. Jacobs |year=2018 |title=Mitogenomics supports an unexpected taxonomic relationship for the extinct diving duck ''Chendytes lawi'' and definitively places the extinct Labrador Duck |journal=Molecular Phylogenetics and Evolution |volume= 122|pages= 102–109|doi=10.1016/j.ympev.2017.12.008 |pmid=29247849 |bibcode=2018MolPE.122..102B |url=https://digitalcommons.calpoly.edu/ssci_fac/99 }}</ref> The other "aberrant" merganser, the smew (''Mergellus albellus''), previously thought to be closer to goldeneyes (''Bucephala'') due to the occurrence of natural hybrids,<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 | publisher=Christopher Helm | publication-place=London | date=1988 | isbn=0-7136-3647-5 | pages=112–115, 274–281}}</ref> is now known to be basal to all the other mergansers from genetic analysis.<ref name="Buckner"/>

Although they are seaducks, most of the mergansers prefer riverine habitats, with only the red-breasted merganser being common at sea. These large fish-eating ducks typically have black-and-white or brown, and with bottle-green heads in the male plumage, while the females are largely grey or brownish and with brown heads; both sexes have somewhat shaggy crests. All have serrated edges to their long and thin bills that help them grip their prey. Along with the smew and hooded merganser, they are therefore often known as "sawbills". The goldeneyes, on the other hand, feed mainly on mollusks, and therefore have a more typical duck-bill.<ref>{{cite web|title=Common Goldeneye|url=http://www.birdweb.org/birdweb/bird/common_goldeneye|publisher=Seattle Audubon Society|access-date=18 April 2014}}</ref>

''Mergus'' ducks are also classified as "diving ducks" because they submerge completely in looking for food. In other traits, however, the genera ''Mergus'', ''Lophodytes'', ''Mergellus'', and ''Bucephala'' are very similar; uniquely among all Anseriformes, they do not have notches at the hind margin of their sternum, but holes surrounded by bone.<ref name=Livezey/>

==Taxonomy== The genus ''Mergus'' was introduced in 1758 by the Swedish naturalist Carl Linnaeus in the tenth edition of his ''Systema Naturae''.<ref>{{cite book | last=Linnaeus | first=Carl | author-link=Carl Linnaeus | year=1758 | title= Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis | volume=1 | edition=10th | page=129 | publisher=Laurentii Salvii | location=Holmiae (Stockholm) | language=Latin | url=https://www.biodiversitylibrary.org/page/727034 }}</ref> The genus name is the Latin word for an unidentified waterbird mentioned by Pliny the Elder and other authors; some sources have identified the original ''mergus'' as referring to either a cormorant or Scopoli's shearwater.<ref>{{cite book | last=Jobling | first=James A. | year=2010| title= The Helm Dictionary of Scientific Bird Names | publisher=Christopher Helm | location=London | isbn= 978-1-4081-2501-4 | page=251 | url=https://archive.org/stream/Helm_Dictionary_of_Scientific_Bird_Names_by_James_A._Jobling#page/n251/mode/1up }}</ref><ref>{{Cite journal |last=Arnott |first=W. G. |date=1964 |title=Notes on Gavia and Mergvs in Latin Authors [Notes on Gavia and Mergus in Latin Authors] |url=https://www.jstor.org/stable/637729 |journal=The Classical Quarterly |volume=14 |issue=2 |pages=249–262 |doi=10.1017/S0009838800023806 |jstor=637729 |s2cid=170648873 |issn=0009-8388|url-access=subscription }}</ref><ref>{{Cite journal |last=White |first=Heather |date=2011 |title=Language and style in Ovid |url=https://ojs.ehu.eus/index.php/Veleia/article/view/6309 |journal=Veleia |language=es |issue=28 |doi=10.1387/veleia.6309 |doi-broken-date=12 July 2025 |issn=2444-3565|hdl=10810/37209 |hdl-access=free }}</ref><ref>{{Cite web |title=Ornithological Approaches to Greek Mythology: The Case of the Shearwater |url=https://camws.org/sites/default/files/meeting2018/abstracts/029.OrnithologicalApproachestoGreekMythology.pdf |website=CAMWS}}</ref> The type species was designated as ''Mergus serrator'' Linnaeus, 1758 (the red-breasted merganser) by Thomas Campbell Eyton in 1838.<ref>{{ cite book | last=Eyton | first=Thomas Campbell | author-link=Thomas Campbell Eyton | date=1838 | title=A Monograph on the Anatidae, or Duck Tribe | location=London | publisher=Longman, Orme, Brown, Green, & Longman | page=76 | url=https://www.biodiversitylibrary.org/page/36002202 }}</ref><ref>{{ cite book | editor1-last=Mayr | editor1-first=Ernst | editor1-link=Ernst Mayr | editor2-last=Cottrell | editor2-first=G. William | year=1979 | title=Check-List of Birds of the World | volume=1 | edition=2nd | publisher=Museum of Comparative Zoology | place=Cambridge, Massachusetts | page=496 | url=https://www.biodiversitylibrary.org/page/16109136 }}</ref><ref>{{ cite book | editor1-last=Dickinson | editor1-first=E.C. | editor1-link=Edward C. Dickinson | editor2-last=Remsen | editor2-first=J.V. Jr. | editor2-link=James Van Remsen Jr. | year=2013 | title=The Howard & Moore Complete Checklist of the Birds of the World | volume=1: Non-passerines | edition=4th | location=Eastbourne, UK | publisher=Aves Press | isbn=978-0-9568611-0-8 | page=12 | url=https://archive.org/details/howardmoorecompl0001howa/page/12/mode/1up | url-access=registration }}</ref>

==Etymology== The genus name is a Latin word used by Pliny the Elder and other Roman authors to refer to an unspecified diving waterbird.<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 | location = London | isbn = 978-1-4081-2501-4 |page =[https://archive.org/details/Helm_Dictionary_of_Scientific_Bird_Names_by_James_A._Jobling/page/251 251]}}</ref><ref name=Arnott/>

The English name ''merganser'', first used in Mediaeval Latin by Conrad Gesner in 1555, and as an English loan word in 1752, means "diving goose", from ''merg'' (as in "submerge"), + ''Anser''.<ref name="Lockwood">{{cite book | last=Lockwood | first=William Burley | title=The Oxford Book of British Bird Names | publisher=Oxford University Press, USA | publication-place=Oxford; New York | date=1984 | isbn=0-19-214155-4 | pages=70–71, 126}}</ref> The name ''goosander'' is older in English usage, first attested in 1622 with the spelling "gossander" and 1674 with its current spelling; it is of unknown etymology but possibly from a Scandinavian origin as "''gossand''", where ''goss'' is unknown, and -''and'' is a duck.<ref name="Lockwood"/>

==Recent species== The genus contains four living species and two recently extinct species.<ref name="Madge"/><ref name=ioc>{{cite web| editor1-last=Gill | editor1-first=Frank | editor1-link=Frank Gill (ornithologist) | editor2-last=Donsker | editor2-first=David | editor3-last=Rasmussen | editor3-first=Pamela | editor3-link=Pamela Rasmussen | date=July 2021 | title=Screamers, ducks, geese & swans | work=IOC World Bird List Version 11.2 | url=http://www.worldbirdnames.org/bow/waterfowl/ | publisher=International Ornithologists' Union | accessdate=24 August 2021 }}</ref><ref>{{Cite web |title=Auckland Island merganser {{!}} Miuweka {{!}} New Zealand Birds Online |url=https://www.nzbirdsonline.org.nz/species/auckland-island-merganser |access-date=2022-05-30 |website=www.nzbirdsonline.org.nz}}</ref><ref name=":0">{{Cite web |title=Chatham Island merganser {{!}} New Zealand Birds Online |url=https://nzbirdsonline.org.nz/species/chatham-island-merganser |access-date=2022-05-30 |website=nzbirdsonline.org.nz |language=en}}</ref>

{{Species table |genus= Mergus |authority-name=Linnaeus |authority-year=1758 |species-count=four|no-note=y|narrow-percent=75}}

{{Species table/row |name= Common merganser Goosander|binomial=Mergus merganser |image=File:Male Goosander 3 (4248116814).jpg|image-size=180px |image-alt=|image-caption=Male |image2 =File:Mergus merganser fem.jpg|image2-caption=Female |authority-name=Linnaeus |authority-year=1758 |authority-not-original= |range= Europe, northern and central Asia, and North America |range-image=File:MergusMerganserIUCNver2019-2.png |range-image-size=180px |size=58–72 cm |habitat=Lakes and rivers; sometimes coastal estuaries when moulting in late summer, and in winter |hunting=Small fish |iucn-status= LC |population= |direction= |subspecies={{Collapsible list |expand=yes |title=Three subspecies |bullets=on | ''M. m. merganser'' Linnaeus, 1758 (goosander; northern Eurasia) | ''M. m. orientalis'' Gould, 1845 (Tibetan goosander; Tibetan Plateau) | ''M. m. americanus'' Cassin, 1852 (common merganser; North America) }} }}

{{Species table/row |name=Brazilian merganser |binomial=Mergus octosetaceus |image=File:Mergus octosetaceus 2.png|image-size=180px |image-alt=|image-caption=Sexes similar |authority-name=Vieillot |authority-year=1817 |authority-not-original= |range= Brazil |range-image=File:Mergus octosetaceus map.svg |range-image-size=180px |size=49–51 cm |habitat=Small fast-flowing rivers in forests |hunting=Small fish |iucn-status= CR |population= |direction= |subspecies= }}

{{Species table/row |name=Red-breasted merganser |binomial=Mergus serrator |image=File:Merganser (53630992394).jpg|image-size=180px |image-alt=|image-caption=Male |image2 =File:Red-breasted Merganser (Mergus serrator).jpg|image2-caption=Female |authority-name=Linnaeus |authority-year=1758 |authority-not-original= |range= Northern North America, Greenland, Europe, and Asia |range-image=File:MergusSerratorIUCN2018 2.png |range-image-size=180px |size=52–58 cm |habitat=Coastal or inland lakes in summer, coastal in winter |hunting=Small fish |iucn-status= LC |population= |direction= |subspecies= }}

{{Species table/row |name=Scaly-sided merganser |binomial=Mergus squamatus |image=File:253 Schuppensäger 2009123ß.JPG|image-size=180px |image-alt=|image-caption=Male |image2=File:Mergus squamatus 522138030.jpg|image2-caption=Female |authority-name=Gould|authority-year= 1864 |authority-not-original= |range= East Asia |range-image= |range-image-size=180px |size=52–62 cm |habitat=Small fast-flowing rivers in forests in summer, larger rivers in winter, rarely on lakes |hunting=Small fish |iucn-status=EN |population= |direction= |subspecies= }}

{|class="wikitable" ! Image !! Scientific name !! Common name!! Distribution |- |120px |†''Mergus australis'' |Auckland Island merganser |Auckland Islands, New Zealand (extinct {{Circa|1902}}). The species identity of merganser bones from mainland New Zealand (North, South, and Stewart Islands) is unresolved.<ref name=":02">Miskelly, Colin & Forsdick, Natalie & Gill, Brian & Palma, Ricardo & Rawlence, Nicolas & Tennyson, Alan. (2022). CHECKLIST OF THE BIRDS OF NEW ZEALAND. https://www.researchgate.net/publication/361824003_CHECKLIST_OF_THE_BIRDS_OF_NEW_ZEALAND</ref> |- | |†''Mergus milleneri'' |Chatham Island merganser |Chatham Island, New Zealand. Extinct sometime after human settlement of the Chatham Islands,<ref name=":0" /> which began c. 1500.<ref>{{Cite web |title=Moriori {{!}} people {{!}} Britannica |url=https://www.britannica.com/topic/Moriori |access-date=2022-05-30 |website=www.britannica.com |language=en}}</ref> |- |}

=== Fossil species === Some fossil members of this genus have been described: * ''Mergus miscellus'' is known from the Middle Miocene Calvert Formation (Barstovian, c. 14 million years ago) of Virginia, USA.<ref>{{cite journal | author1=Alvarez, R. | author2=Olson, S.L. | journal=Proceedings of the Biological Society of Washington | title=A New Merganser From The Miocene Of Virginia (Aves: Anatidae | volume=91 | pages=522–532 | date= 1978 | url=https://www.biodiversitylibrary.org/part/45680}}</ref> * ''Mergus connectens'' lived in the Early Pleistocene about 2–1 million years ago, in Central and Eastern Europe.<ref name="Mlikovsky2002a" />

The Early Oligocene booby ''"Sula" ronzoni'' was at first mistakenly believed to be a typical merganser.<ref>Mlíkovský (2002b): p. 264</ref> A Late Serravallian (13–12 million years ago) fossil sometimes attributed to ''Mergus'', found in the Sajóvölgyi Formation of Mátraszőlős, Hungary, probably belongs to ''Mergellus''.<ref name="Gal" /> The affiliations of ''"Anas" albae'' from the Messinian (c. 7–5 million years ago) of Hungary are undetermined; it was initially believed to be a typical merganser too.<ref>Mlíkovský (2002b): p. 124</ref>

==References== {{Reflist|refs= <ref name=Arnott>Etymology: Latin ''mergus'', a catch-all term for sea-going birds: {{cite journal|author=Arnott, W.G. |year=1964|title= Notes on ''Gavia'' and ''Mergvs'' in Latin Authors|journal=Classical Quarterly |series=New Series |volume=14|issue=2|pages= 249–262|jstor=637729|doi=10.1017/S0009838800023806 |s2cid=170648873 }}</ref> <ref name=Gal>{{cite journal|author1=Gál, Erika|author2=Hír, János|author3=Kessler, Eugén|author4=Kókay, József|name-list-style=amp|year=1998–99|title=Középsõ-miocén õsmaradványok, a Mátraszõlõs, Rákóczi-kápolna alatti útbevágásból. I. A Mátraszõlõs 1. lelõhely [Middle Miocene fossils from the sections at the Rákóczi chapel at Mátraszőlős. Locality Mátraszõlõs I.]|journal=Folia Historico Naturalia Musei Matraensis|volume=23|pages=33–78|language=Hungarian, English|url=http://www.matramuzeum.hu/Personal/folia/23/03MATSZOLOS.PDF|access-date=2007-02-06|archive-url=https://web.archive.org/web/20110721111701/http://www.matramuzeum.hu/Personal/folia/23/03MATSZOLOS.PDF|archive-date=2011-07-21|url-status=dead}}</ref><ref name=Livezey>{{cite journal|author=Livezey, Bradley C. |year=1986|title= A phylogenetic analysis of recent anseriform genera using morphological characters|journal=Auk|volume=103|issue=4|pages= 737–754|doi=10.1093/auk/103.4.737|url=http://sora.unm.edu/sites/default/files/journals/auk/v103n04/p0737-p0754.pdf}}</ref> <ref name=Mlikovsky2002a>{{cite journal|author=Mlíkovský, Jirí|year=2002a|title=Early Pleistocene birds of Stránská skála, Czech Republic: 2. Absolon's cave|journal=Sylvia|volume=38|pages=19–28|url=http://www.nm.cz/download/JML-11-2002-stranska-skala.pdf|access-date=2008-08-05|archive-url=https://web.archive.org/web/20160411211257/http://www.nm.cz/download/JML-11-2002-stranska-skala.pdf|archive-date=2016-04-11|url-status=dead}}</ref> }} {{Commons category}}

==Further reading== * Mlíkovský, Jirí (2002b): [https://web.archive.org/web/20110520101755/http://www.nm.cz/download/JML-18-2002-CBE.pdf ''Cenozoic Birds of the World, Part 1: Europe'']. Ninox Press, Prague.

Category:Mergus Category:Bird genera Category:Mergansers Category:Langhian first appearances Category:Extant Miocene first appearances Category:Animal taxa named by Carl Linnaeus