Editing Ruby-crowned kinglet (section)

== Description ==
The ruby-crowned kinglet is a very small bird, being {{convert|9|to|11|cm|in|1|sp=us|abbr=on}} long, having a wingspan of {{convert|16|to|18|cm|in|1|sp=us|abbr=on}}, and weighing {{convert|5|to|10|g|oz|1|sp=us|abbr=on}}.<ref name=AAB>{{cite web |title=Ruby-crowned Kinglet|work=Cornell Lab of Ornithology Bird Guide|publisher=Cornell Lab of Ornithology|year =1994|url=http://www.allaboutbirds.org/guide/Ruby-crowned_Kinglet/lifehistory|access-date=2 November 2010}}</ref> It has gray-green upperparts and olive-[[buff (color)|buff]] underparts.<ref name=BirdsOfMaine>{{cite book |title= The birds of Maine |last=Knight|first=Ora Willis|year=1908|publisher=C. H. Glass & co.|location=[[Bangor, Maine|Bangor]]|isbn=978-1-145-46819-1|pages=[https://archive.org/details/birdsmainewithk00kniggoog/page/n666 616]–619|url=https://archive.org/details/birdsmainewithk00kniggoog|access-date=1 November 2010}}</ref> It has two white wingbars and a broken white eye ring. The wingbar on the greater secondary coverts (closer to the wing-tip) is wider, and is next to a dark band. The kinglet has a relatively plain face and head, although the male has a scarlet-red crown patch, which is usually concealed by the surrounding feathers. The crown patch is rarely orange, yellow, or not present.<ref name="BNA Characteristics">{{cite web|url=http://bna.birds.cornell.edu/bna/species/119/articles/characteristics|title=Ruby-crowned Kinglet: Distinguishing Characteristics|last1=Ingold|first1=J L|last2=Wallace|first2=G E|date=28 July 2008|work=The Birds of North America Online|publisher=Cornell Lab of Ornithology|access-date=3 November 2010}}</ref> Females are identical to males (except for the crown). Immature birds are similar to adult females, since young males lack a crown patch.<ref name="BirdsOfMaine"/> The kinglet usually moves along branches or through foliage with short hops, and flies with bursts of rapid wing beats. It is constantly active, and is easily recognized by its characteristic wing-flicking. Its flight has been described as "swift, jerky, and erratic".<ref name="Dunne">{{cite book |title=Pete Dunne's essential field guide companion|last=Dunne|first=Peter|year=2006|publisher=Houghton Mifflin Harcourt|location=New York|isbn=978-0-618-23648-0|page=[https://archive.org/details/petedunnesessent00dunn/page/487 487]|url=https://archive.org/details/petedunnesessent00dunn|url-access=registration|access-date=3 November 2010}}</ref>

Compared to the related [[golden-crowned kinglet]], the ruby-crowned kinglet is slightly larger, more elongated,<ref name="Sibley">{{cite book|title=The Sibley Guide to Birds|last=Sibley|first=David Allen|author-link=David Allen Sibley|year=2000|publisher=Alfred A. Knopf|location=New York|isbn=978-0-679-45122-8|page=[https://archive.org/details/sibleyguidetobir00sibl_0/page/394 394]|url=https://archive.org/details/sibleyguidetobir00sibl_0/page/394}}</ref> and has greener plumage. The bird can be mistaken for [[Hutton's vireo]], which also displays wing-flicking, though less frequently than the kinglet. It can also be mistaken for the [[dwarf vireo]] in Mexico. However, both of the vireos are larger, have stouter bills and legs, and lack the kinglet's black bar on the wings.<ref name="BNA Characteristics"/>
<gallery mode=packed>
Ruby-crowned Kinglet.jpg|Rare flashing of ruby crest
Ruby-crowned Kinglet1.jpg|Close-up on head
Regulus calendula Dobak.jpg|Reverse view of male, showing the red crown
Ruby-crowned Kinglet2.jpg|Tail plumage
Regulus calendula-perching.jpg|Underparts
</gallery>

===Vocalization===
The ruby-crowned kinglet's vocalizations are remarkably loud and complex for its size. Its song can be divided into three main parts: a series of high pitched notes (''zee-zee-zee'' or ''tee-tee-tee''), two to five low trills (''turr'' or ''tu''), and a repeated three note "galloping" phrase (''tee-da-leet'', ''tee-da-leet'').<ref name="Borror">{{cite book |title=Songs of Eastern Birds|last=Borror|first=Donald J|year=1984|publisher=Dover Publications|location=[[Don Mills]]|isbn=978-0-486-99912-8|pages=44–45|url=https://books.google.com/books?id=dikA-15BLVEC&pg=PA44|access-date=3 November 2010}}</ref> However, there is variation in the songs of a given individual, and they often contain only one or two of the three parts. The third part is only sung by male birds; an abbreviated version is heard from the females. Other vocalizations of the ruby-crowned kinglet include alarm calls, simple [[contact calls]], and begging calls produced by chicks.<ref name="BNA Voice">{{cite web|url=http://bna.birds.cornell.edu/bna/species/119/articles/sounds|title=Ruby-crowned Kinglet: Sounds|last1=Ingold|first1=J L|last2=Wallace|first2=G E|date=28 July 2008|work=The Birds of North America Online|publisher=Cornell Lab of Ornithology|access-date=3 November 2010}}</ref>

The subspecies ''C. c. grinnellii'', breeding from southeastern [[Alaska]] to [[British Columbia]] differs significantly from the nominate ''calendula'', and so is considered to represent a valid subspecies: it is smaller and shorter-winged, its upperparts are darker and greener, its underparts are buffy rather than grayish-olive, and the vent is tinged yellow rather than dull whitish-olive.<ref name="Pyle">pp. 375–76 in {{cite book| last = Pyle | first = Peter | title = Identification Guide to North American Birds Part 1 | year = 1997 | publisher = Slate Creek Press | location = Bolinas, California | isbn = 978-0-9618940-2-3 | title-link = Identification Guide to North American Birds }}</ref>

The subspecies ''C. c. obscurus'', from [[Guadalupe Island]], off [[Baja California]], is considered endangered, and may already be extinct.<ref name = hbw>Martens, Jochen; Päckert, Martin "Family Regulidae (Kinglets & Firecrests)" pp. 330–349 in {{cite book| editor-last = del Hoyo | editor-first = Josep | editor2-last = Elliott | editor2-first = Andrew | editor3-last = Christie | editor3-first = David A. | title = Handbook of the Birds of the World Volume 11: Old World Flycatchers to Old World Warblers | year =2006 | publisher = [[Lynx Edicions]] | location = Barcelona | isbn = 978-84-96553-06-4 | title-link = Handbook of the Birds of the World }}</ref>

Hybridization with [[golden-crowned kinglet]]s has been reported to have possibly occurred.<ref name = "Pyle"/>