Editing Horned grebe (section)

===Subspecies and distribution===
Two [[subspecies]] are accepted:<ref name=ioc/>
{| class="wikitable "
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! Summer !! Winter !! Scientific name !! Common name !! Summer distribution !! Winter distribution
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|[[File:Podiceps auritus (13909575538) (cropped).jpg|120px]] || [[File:Slavonian Grebe (45502756154).jpg|120px]] || ''P. a. auritus'' ([[Carl Linnaeus|Linnaeus]], 1758) || Slavonian grebe || Small populations in [[Iceland]], [[Scotland]], and [[Norway]], and extensively from [[Sweden]] eastwards through Russia, northern [[Kazakhstan]] and northwest Mongolia to the [[Russian Far East]] in south [[Chukchi Peninsula|Chukotka]], [[Sakhalin]] and the [[Kamchatka Peninsula]] (east Russia) || Inshore waters of the Atlantic coast of Europe from Iceland and Norway south to northwestern France, in the eastern Mediterranean Sea, the Black Sea, and the Caspian Sea, and the Pacific coasts of Asia from northern [[Japan]], [[Korea]], south to eastern [[China]].<ref name="HBW"/>
|-
|[[File:Horned Grebe (8703426662).jpg|120px]] || [[File:Horned Grebe (33068913511).jpg|120px]] || ''P. a. cornutus'' ([[Johann Friedrich Gmelin|Gmelin, JF]], 1789) || Horned grebe || Subarctic south and central [[Alaska]] mainland, central and western [[Canada]] from [[Yukon]] east to northwestern [[Ontario]], but also a small disjunct population on the [[Magdalen Islands|Magdalene Islands]] in the [[Gulf of St. Lawrence]] in [[Quebec]],<ref>{{Cite web|url=http://www3.mffp.gouv.qc.ca/faune/especes/menacees/fiche.asp?noEsp=6|title=Horned Grebe List of wildlife species threatened or vulnerable in Quebec|year=2010}}</ref> and the northern tier of west-central contiguous USA states from northeastern [[Washington (state)|Washington]] to [[Minnesota]] || Inshore waters of the Pacific and Atlantic coasts of North America, from southern Alaska south to [[California]] and the northern [[Gulf of California]], and [[Nova Scotia]] south to [[Texas]].<ref name="HBW"/>
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|}

The subspecies are physically similar in measurements, but differ subtly in plumage, with ''P. a. auritus'' darker, having a blacker back and crown, and orange-yellow lateral crown tufts in breeding plumage; and ''P. a. cornuta'' paler, with greyer back and crown, and straw-yellow tufts.<ref name="BWP"/><ref>{{Cite journal|last=Parkers|year=1952|title=Geographic variation in the Horned Grebe|journal=Condor|volume=54|issue=5|pages=314–315|doi=10.2307/1364948|jstor=1364948}}</ref>

A third subspecies ''P. a. arcticus'' <small>Boie, 1822</small> has sometimes been accepted for the population in coastal Norway, Iceland, and Scotland,<ref name="Fjeldså"/> but is now treated as synonymous with nominate ''P. a. auritus''.<ref name="BWP"/><ref name="HBW"/>

In winter plumage, it is often confused with the [[black-necked grebe]], which is only slightly smaller in size and has similar colouring but is differentiated by a steeper forehead, a more slender, slightly uptilted bill, duskier cheeks, and a fluffier rump.<ref name="BWP"/><ref name=":0">{{Cite web|url=http://www.sararegistry.gc.ca/virtual_sara/files/cosewic/sr_horned_grebe_0809_e.pdf|title=COSEWIC Assessment and Status Report on the Horned Grebe Podiceps auritus.|year=2016}}</ref>