Editing American redstart (section)

==Description==
[[File:American Redstart of Quintana Texas1.jpg|thumb|left|American redstart of [[Quintana, Texas]]]]
The American redstart is a smallish warbler. It measures {{convert|11|to|14|cm|in|abbr=on}} in total length and has a wingspan of {{convert|16|to|23|cm|in|abbr=on}}. Its length is boosted by a relatively long tail and it is one of the lightest birds in its family.<ref>[[Robert Ridgway|Ridgway, R.]] 1902. ''The birds of North and Middle America: a descriptive catalogue of the higher groups, genera, species, and subspecies of birds known to occur in North America''. U.S. National Museum Bulletin no. 50.</ref> Weight is considerably less in winter than in summer. Males weigh an average of {{convert|8.6|g|oz|abbr=on}} in summer but drop to {{convert|7.2|g|oz|abbr=on}} in winter, while females drop even more from an average of {{convert|8.7|g|oz|abbr=on}} to an average of {{convert|6.9|g|oz|abbr=on}}.<ref>Holmes, R. T. 1986. ''Foraging behavior of forest birds: male-female differences''. Wilson Bulletin, 98:196-213.</ref><ref>Sherry, T. W. and R. T. Holmes. 1996. ''Winter habitat limitation in Neotropical-Nearctic migrant birds: implications for population dynamics and conservation''. Ecology 77:36-48.</ref> Among standard measurements, the [[Wing chord (biology)|wing chord]] is {{convert|5.5|to|6.9|cm|in|abbr=on}}, the [[tail]] is {{convert|4.9|to|5.8|cm|in|abbr=on}}, the [[Beak|bill]] is {{convert|0.7|to|0.9|cm|in|abbr=on}} and the [[Tarsus (skeleton)|tarsus]] is {{convert|1.5|to|1.9|cm|in|abbr=on}}.<ref>''New World Warblers (Helm Field Guides)'' by Jon Curson. Christopher Helm Publishers (1993). 978-0713639322.</ref> The breeding males are unmistakable, jet black above apart from large orange-red patches on their wings and tails. Their breast sides are also orange, with the rest of their underparts white. In their other plumages, American redstarts display green in their upperparts, along with black central tails and grey heads. The orange patches of the breeding males are replaced by yellow in the plumages of the females and young birds. Orange and yellow coloration is due to the presence of [[carotenoid]]s; males possess the red carotenoid canthaxanthin and the yellow carotenoids canary xanthophyll A and B, all of which mix together to produce an orange color, while the females possess only the yellow carotenoids. Recent research indicates that an age and sex effect on observed color attributes of hue, brightness, and saturation exists in American redstarts, with the exception for saturation, which only showed an age effect.<ref>{{cite thesis|last=Faris|first=Michael|title=Determination and Quantitation of Carotenoids in ''Setophaga ruticilla'' Feathers|url=http://digitalservices.scranton.edu/cdm/ref/collection/p15111coll1/id/798|degree=M.A.|publisher=University of Scranton|access-date=10 April 2012|year=2011}}</ref> Their song is a series of musical ''see'' notes. Their call is a soft ''chip''.