Editing Common raven (section)

== Description ==
{{For|physiology|Common raven physiology}}
[[File:Raven Cypress Provincial Park 2.JPG|thumb|left|In sunlight, the [[plumage]] can display a blue or purple sheen which is a result of [[iridescence]].]]
A mature common raven ranges between {{convert|54|and|71|cm|in|abbr=on}} and has a [[wingspan]] of {{convert|116|to|153|cm|in|abbr=on}}.<ref>{{cite book |last1=Svensson |first1=Lars |last2=Mullarney |first2=Killian |last3=Zetterström |first3=Dan |date=2015 |title=Le guide ornitho: le guide le plus complet des oiseaux d'Europe, d'Afrique du Nord et du Moyen-Orient |trans-title=The birding guide: The most comprehensive guide of birds from Europe, North Africa and the Middle East |location=French |publisher=Éditions Delachaux et Niestlé }}</ref><ref>{{Cite web|title=Common Raven|url=http://nature.ca/notebooks/english/raven.htm |archive-url=https://web.archive.org/web/20170623101737/http://nature.ca/notebooks/english/raven.htm |archive-date=2017-06-23 |website=Canadian Museum of Nature |url-status=dead}}</ref><ref>{{Cite web|title=Raven|url=https://www.garden-birds.co.uk/birds/raven.html|access-date=2012-12-19|website=British Garden Birds}}</ref> Recorded weights range from {{convert|0.69|to|2.250|kg|lbs|abbr=on}},<ref name="Boarman_Heinrich">{{cite journal|last1=Boarman| first1=William I.|last2=Heinrich|first2=Bernd| year=1999| title=Common Raven (''Corvus corax'')| journal=Birds of North America| volume=476| pages=1–32|doi=10.2173/bna.476|editor1-last=Poole|editor1-first=A.|editor2-last=Gill|editor2-first=F.}}</ref><ref>{{Cite web|title=Common Raven|url=https://www.oiseaux-birds.com/card-common-raven.html|access-date=2012-12-19|website=www.oiseaux-birds.com}}</ref> thus making the common raven one of the heaviest [[passerine]]s. Birds from colder regions such as the [[Himalayas]] and Greenland are generally larger with slightly larger bills, while those from warmer regions are smaller with proportionally smaller bills.<ref>[[#Goodwin|Goodwin]], pp. 138–139</ref> Representative of the size variation in the species, ravens from [[California]] weighed an average of {{convert|0.784|kg|lb|abbr=on}}, those from [[Alaska]] weighed an average of {{convert|1.135|kg|lb|abbr=on}} and those from [[Nova Scotia]] weighed an average of {{convert|1.230|kg|lb|abbr=on}}.<ref>{{cite journal|author=Elliot, R. D. |year=1977|title=Hanging behavior in Common Ravens|doi=10.2307/4085278|jstor=4085278|journal= Auk |volume=94|issue=4|pages=777–778|url=https://sora.unm.edu/node/23073|url-access=subscription}}</ref><ref>{{Cite journal | doi = 10.1016/0300-9629(78)90033-6| title = Temperature regulation in the common raven of interior Alaska| journal = Comparative Biochemistry and Physiology A| volume = 60| pages = 31–36| year = 1978| last1 = Schwan | first1 = M. W. | last2 = Williams | first2 = D. D. | issue = 1}}</ref><ref>Linz, G. M., Knittle, C. E. and Johnson, R. E. (1990). ''Ecology of corvids in the vicinity of the Aliso Creek California Least Tern colony, Camp Pendelton, California''. U.S. Dept. of Agric., North Dakota Field Stn. North Dakota State Univ., Fargo.</ref> The [[beak|bill]] is large and slightly curved, with a [[Culmen (bird)|culmen]] length of {{convert|5.7|to|8.5|cm|in|abbr=on}}, one of the largest bills amongst passerines (only the [[thick-billed raven]] and [[white-necked raven]] have larger bills<ref name="HBW"/>). It has a longish, strongly graduated tail, at {{convert|20|to|26.3|cm|in|abbr=on}}, and mostly [[iridescent]] black plumage, and a dark brown [[Iris (anatomy)|iris]]. The throat feathers are elongated and pointed and the bases of the neck feathers are pale brownish-grey. The legs and feet are stout and strong, with a [[Tarsus (skeleton)|tarsus]] length of {{convert|6|to|7.2|cm|in|abbr=on}}.<ref>{{cite journal|author=Oberholser, Harry C. |title=The Common Ravens of North America |journal=The Ohio Journal of Science |volume=18 |issue=6 |year=1918 |pages=213–225 |hdl=1811/1993 }}</ref><ref>Anonymous. (2013) [https://archive.today/20130415015528/http://avis.indianbiodiversity.org/passeriformes-corvidae-crows-jays-ravens-and-magpies/common-raven-corvus-corax.html "''Corvus corax'' – Linnaeus, 1758 (Common Raven)"] in Deomurari, A.N. (Compiler), 2010. AVIS-IBIS (Avian Information System – Indian BioDiversity Information System) v. 1.0. Foundation For Ecological Security, India</ref> The juvenile plumage is similar but duller, with a blue-grey iris, and pinkish gape at first.<ref>[[#Goodwin|Goodwin]], p. 138</ref>
[[File:Crow and Raven, Restricted Access- Camp Edwards, Bourne, MA, USA imported from iNaturalist photo 444490042 (cropped).jpg|thumb|Comparison between an American crow (left) and a common raven (right)]]
Apart from its greater size, the common raven differs from related [[crow]]s by having a larger and heavier black beak, shaggy feathers around the throat, longer bristles above the beak, and a longer, wedge-shaped tail.<ref name="Collins">[[Lars Svensson (ornithologist)|Svensson, L.]], [[Killian Mullarney|Mullarney, K.]], & [[Dan Zetterström|Zetterström, D.]] (2022) ''[[Collins Bird Guide]]'', ed. 3. {{ISBN|978-0-00-854746-2}}, pages 380–381</ref> Flying ravens are distinguished from crows by their tail shape, larger wing area, and more stable soaring style, which generally involves less wing flapping. Despite their bulk, ravens are easily as agile in flight as their smaller cousins. In flight the feathers produce a creaking sound that has been likened to the rustle of silk.<ref name=hbk/> The voice of ravens is also quite distinct, its usual call being a deep croak of a much more sonorous quality than a crow's call, though the calls of other ravens like the [[fan-tailed raven]] and [[brown-necked raven]] can be confused where they occur together with common ravens in parts of southwest Asia and northern Africa;<ref name="Snow">{{cite book | last=Snow | first=David William | title=The Birds of the Western Palaearctic, Concise Edition | publisher=Oxford Univ. Press | publication-place=Oxford | date=1998 | isbn=0-19-854099-X | volume=2 | pages=1483–1486}}</ref> of these two, the fan-tailed raven is more similar in calls but has a very different shape with its broad wings and very short tail, while the brown-necked raven can be very hard to distinguish on plumage, but has somewhat more crow-like calls.<ref name="Collins"/> In North America, the [[Chihuahuan raven]] (''C. cryptoleucus'') is fairly similar to the relatively small common ravens of the American southwest and is best distinguished by the still relatively smaller size of its bill, beard and body and relatively longer tail.<ref>Boarman, William I. and Heinrich, Bernd  (1999) [http://bna.birds.cornell.edu/bna/species/476/articles/introduction ''Common Raven (Corvus corax)''], The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology.</ref> The all-black [[carrion crow]] (''C. corone'') and [[rook (bird)|rook]] (''C. frugilegus'') in Europe may suggest a raven due to their largish bill but are still distinctly smaller and have the wing and tail shapes typical of crows.<ref name="Snow"/><ref name="Collins"/>
[[File:Common Raven imported from iNaturalist photo 338614949 on 6 December 2024.jpg|thumb|Leucistic. [[Anchorage White Raven|This individual]] is locally well known in [[Anchorage, Alaska|Anchorage]] (Alaska).<ref>{{Cite web |last=Anchorage |first=Rhonda McBride, KNBA- |date=2024-01-30 |title=Anchorage's white raven becomes a local legend as a tracked trickster |url=https://alaskapublic.org/2024/01/30/anchorages-white-raven-becomes-a-local-legend-as-a-tracked-trickster/ |access-date=2024-12-10 |website=Alaska Public Media |language=en-US}}</ref>]]
In the [[Faroe Islands]], a now-extinct pied colour morph of this species existed, known as the [[pied raven]];<ref>{{Cite journal | last = Droste | first = Ferdinand Baron von | title = Vogelfauna der Färöer (Färöernes Fuglefauna af Sysselmaand Müller 1862.) Aus dem Dänischen übersetzt und mit Anmerkungen versehen. Teil 1 |language = de| journal = [[Journal of Ornithology]] | volume = 17 | issue = 2 | pages = 107–118 | year = 1869 | doi = 10.1007/BF02261546| bibcode = | s2cid = 43875817 | url = https://www.biodiversitylibrary.org/part/142067 }}</ref> the ordinary black-coloured common ravens remain widespread in the archipelago.<ref name=FObl>{{cite web| title=Liste over Færøernes fugle | url=https://www.dof.dk/images/udvalg/su/dokumenter/su_rapporter/Faeroliste_udg._16a.pdf | publisher=[[Dansk Ornitologisk Forening]] | access-date=31 July 2023 }}</ref> White ravens are occasionally found in the wild. Some in [[British Columbia]] lacked the pink eyes of an albino, and were instead [[leucistic]], a condition where an animal lacks any of several different types of pigment, not simply [[melanin]].<ref name = dearing>{{cite web| author =Dearing, Stephanie | title=Another rare white raven born this year on Canadian beach | url=http://www.digitaljournal.com/article/294246  |work=Digital Journal |date=5 July 2010| access-date = 7 November 2014}}</ref>
[[File:Two Ravens Talking Mar 10 2012.ogv|thumb|Vocalising]]

Common ravens have a wide range of [[Bird vocalization|vocalization]]s which are of interest to [[ornithologist]]s. Gwinner carried out important studies in the early 1960s, recording and photographing his findings in great detail.<ref name="Gwinner64">{{cite journal|language= de|doi=10.1111/j.1439-0310.1964.tb01212.x|last=Gwinner| first=E.| year=1964| title=Untersuchungen über das ausdrucks und Sozialverhalten des Kolkraben (''Corvus corax'' L.)| journal=Zeitschrift für Tierpsychologie| volume=21| issue=6| pages=657–748}}</ref> Fifteen to 30 categories of calls have been recorded for this species, most of which are used for social interaction. Calls recorded include alarm calls, chase calls, and flight calls. The species has a distinctive, deep, resonant ''prruk-prruk-prruk'' call, which to experienced listeners is unlike that of any other corvid. Its very wide and complex vocabulary includes a high, knocking ''toc-toc-toc'', a dry, grating ''kraa'', a low guttural rattle and some calls of an almost musical nature.<ref name="Gwinner64"/>

Like other corvids, the common raven can mimic sounds from their environment, including human speech. Non-vocal sounds produced by the common raven include wing whistles and bill snapping. Clapping or clicking has been observed more often in females than in males. If a member of a pair is lost, its mate reproduces the calls of its lost partner to encourage its return.<ref>[[#Goodwin|Goodwin]], p. 142</ref>