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The dark-eyed junco (''Junco hyemalis'') is the best-known species of the juncos, a genus of small grayish American sparrows. This bird is common across much of temperate North America and in summer ranges far into the Arctic. It is a very variable species, much like the related fox sparrow (''Passerella iliaca''), and its systematics are still not completely untangled. ==Description== Adults generally have gray heads, necks, and breasts, gray or brown backs and wings, and a white belly, but show a confusing amount of variation in plumage details. The white outer tail feathers flash distinctively in flight and while hopping on the ground. The bill is usually pale pinkish.〔 Males tend to have darker, more conspicuous markings than the females. The dark-eyed junco is long and has a wingspan of .〔〔Rising, J.D. (2010) ''A Guide to the Identification and Natural History of the Sparrows of the United States and Canada''. Christopher Helm Publishers, London, ISBN 1408134608.〕 Body mass can vary from .〔 Among standard measurements, the wing chord is , the tail is , the bill is and the tarsus is .〔''Sparrows and Buntings: A Guide to the Sparrows and Buntings of North America and the World'' by Clive Byers & Urban Olsson. Houghton Mifflin (1995). ISBN 978-0395738733.〕 Juveniles often have pale streaks and may even be mistaken for vesper sparrows (''Pooecetes gramineus'') until they acquire adult plumage at 2 to 3 months. But junco fledglings' heads are generally quite uniform in color already, and initially their bills still have conspicuous yellowish edges to the gape, remains of the fleshy wattles that guide the parents when they feed the nestlings. The song is a trill similar to the chipping sparrow's (''Spizella passerina''), except that the red-backed junco's (see below) song is more complex, similar to that of the yellow-eyed junco (''Junco phaeonotus''). The call also resembles that of the black-throated blue warbler's, which is a member of the New World warbler family.〔(【引用サイトリンク】work=Birds in Forested Landscapes )〕 Calls include ''tick'' sounds and very high-pitched tinkling ''chip''s.〔 It is known among bird language practitioners as an excellent bird to study for learning "bird language." A sample of the song can be heard at the USGS web site (here ) (MP3) or at the Cornell Lab of Ornithology web site (here ). 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Dark-eyed junco」の詳細全文を読む スポンサード リンク
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