Supercilium: Difference between revisions – Wikipedia

 

Line 2: Line 2:

[[File:Saxicola rubetra 2 tom (Marek Szczepanek).jpg|thumb|right|upright|The [[whinchat]] has a prominent white supercilium.]]

[[File:Saxicola rubetra 2 tom (Marek Szczepanek).jpg|thumb|right|upright|The [[whinchat]] has a prominent white supercilium.]]

The ”’supercilium”’ is a [[plumage]] feature found on the heads of some [[bird]] species. It is a stripe which runs from the base of the bird’s [[beak]] above its eye, finishing somewhere towards the rear of the bird’s head.<ref name=”Dunn”>Dunn and Alderfer (2006), p. 10</ref> Also known as an “eyebrow”,<ref name=”Dunn”/> it is distinct from the [[eyestripe]], which is a line that runs across the [[Lore (anatomy)|lores]], and continues behind the eye.<ref>Dunn and Alderfer (2006), p. 11</ref> Where a stripe is present only above the lores, and does not continue behind the eye, it is called a ”’supraloral stripe”’ or simply ”’supraloral”’.<ref name=”Dunn”/> On most species which display a supercilium, it is paler than the adjacent [[feather tract]]s.<ref>Kaufman, Kenn (2011) A Field Guide to Advanced Birding {{ISBN|978-0-547-24832-5}}, page 51</ref>

The ”’supercilium”’ is a [[plumage]] feature found on the heads of some [[bird]] species. It is a stripe runs from the base of the bird’s [[beak]] above its eye, finishing somewhere towards the rear of the bird’s head.<ref name=”Dunn”>Dunn and Alderfer (2006), p. 10</ref> Also known as an “eyebrow”,<ref name=”Dunn”/> it is distinct from the [[eyestripe]], which is a line that runs across the [[Lore (anatomy)|lores]], and continues behind the eye.<ref>Dunn and Alderfer (2006), p. 11</ref> Where a stripe is present only above the lores, and does not continue behind the eye, it is called a supraloral stripe or simply supraloral.<ref name=”Dunn”/> On most species display a supercilium, it is paler than the adjacent [[feather tract]]s.<ref>Kaufman, Kenn (2011) A Field Guide to Advanced Birding {{ISBN|978-0-547-24832-5}}, page 51</ref>

The colour, shape or other features of the supercilium can be useful in bird identification. For example, the supercilium of the [[dusky warbler]], an [[Old World warbler]] species, can be used to distinguish it from the very similar [[Radde’s warbler]]. The dusky warbler’s supercilium is sharply demarcated, whitish and narrow in front of the eye, becoming broader and more buffy towards the rear, whereas that of the Radde’s warbler is diffusely defined, yellowish and broadest in front of the eye, becoming narrower and more whitish toward the rear.<ref>{{cite book |title=Collins Bird Guide |first1=Killian |last1=Mullarney |first2=Lars |last2=Svensson |first3=Dan |last3=Zetterström |first4=Peter J |last4=Grant |year=1999 |publisher=HarperCollins |location=London |isbn=0-00-219728-6 |pages=306–307}}</ref> The supercilium of the [[northern waterthrush]], a [[New World warbler]], differs subtly from that of the closely related (and similarly plumaged) [[Louisiana waterthrush]]. The Louisiana has a bicoloured supercilium which widens significantly behind the eye, while the northern has an evenly buffy eyebrow which is either the same width throughout or slightly narrower behind the eye.<ref>Dunn and Alderfer (2006), p. 394.</ref>

The colour, shape or other features of the supercilium can be useful in bird identification. For example, the supercilium of the [[dusky warbler]], an [[Old World warbler]] species, can be used to distinguish it from the very similar [[Radde’s warbler]]. The dusky warbler’s supercilium is sharply demarcated, whitish and narrow in front of the eye, becoming broader and more buffy towards the rear, whereas that of the Radde’s warbler is diffusely defined, yellowish and broadest in front of the eye, becoming narrower and more whitish toward the rear.<ref>{{cite book |title=Collins Bird Guide |first1=Killian |last1=Mullarney |first2=Lars |last2=Svensson |first3=Dan |last3=Zetterström |first4=Peter J |last4=Grant |year=1999 |publisher=HarperCollins |location=London |isbn=0-00-219728-6 |pages=306–307}}</ref> The supercilium of the [[northern waterthrush]], a [[New World warbler]], differs subtly from that of the closely related (and similarly plumaged) [[Louisiana waterthrush]]. The Louisiana has a bicoloured supercilium which widens significantly behind the eye, while the northern has an evenly buffy eyebrow which is either the same width throughout or slightly narrower behind the eye.<ref>Dunn and Alderfer (2006), p. 394.</ref>

A ”’split supercilium”‘ divides above the lores. In some species, such as the [[jack snipe]], the divided stripes reconnect again behind the eye.<ref>Hayman, Marchant and Prater (1986), p. 359</ref> In others, such as the [[broad-billed sandpiper]], the divided stripes remain separate.<ref>Hayman, Marchant and Prater (1986), p. 383</ref>

A split supercilium’ divides above the lores. In some species, such as the [[jack snipe]], the divided stripes reconnect again behind the eye.<ref>Hayman, Marchant and Prater (1986), p. 359</ref> In others, such as the [[broad-billed sandpiper]], the divided stripes remain separate.<ref>Hayman, Marchant and Prater (1986), p. 383</ref>

A ”’supercilium drop”’ is a feature found on some [[pipit]]s;<ref>{{cite book |last1=Harris |first1=Alan |first2=Laurel |last2=Tucker |first3=Keith |last3=Vinicombe |year=1989 |title=The MacMillan Field Guide to Bird Identification |isbn=1-85627-641-4 |page=158|publisher=Grange Books }}</ref> it is a pale spot on the rear of the {{birdgloss|ear–coverts}} which, although separated from the supercilium by an eyestripe, can appear at some angles to be a downward continuation of the supercilium.

A supercilium drop is a feature found on some [[pipit]]s;<ref>{{cite book |last1=Harris |first1=Alan |first2=Laurel |last2=Tucker |first3=Keith |last3=Vinicombe |year=1989 |title=The MacMillan Field Guide to Bird Identification |isbn=1-85627-641-4 |page=158|publisher=Grange Books }}</ref> it is a pale spot on the rear of the {{birdgloss|earcoverts}} which although separated from the supercilium by an eyestripe, can appear at some angles to be a downward continuation of the supercilium.

== Gallery ==

== Gallery ==

<gallery heights=”120″>

<gallery heights=”120″>

File:Wilsonia canadensis.jpg|The [[Canada warbler]] shows a yellow supraloral.

File:Wilsonia canadensis.jpg|The [[Canada warbler]] shows a yellow supraloral.

File:Limicola falcinellus Taiwan cropped.jpg|The [[broad-billed sandpiper]] has a split supercilium…

File:Limicola falcinellus Taiwan cropped.jpg|The [[broad-billed sandpiper]] has a split supercilium

File:Lymnocryptes minimus (Marek Szczepanek).jpg|…as does the [[jack snipe]].

File:Lymnocryptes minimus (Marek Szczepanek).jpg|as does the [[jack snipe]].

File:Olive-backed Pipit- Kolkata I IMG 9872.jpg|The olive-backed pipit has a supercilium drop.

File:Olive-backed Pipit- Kolkata I IMG 9872.jpg|The olive-backed pipit has a supercilium drop.

</gallery>

</gallery>

==References==

==References==

===Notes===

{{reflist|2}}

{{reflist|2}}

===Sources===

======

*x

*{{cite book |title=Field Guide to the Birds of North America |editor1-first=Jon L. |editor1-last=Dunn |editor2-first=Jonathan |editor2-last=Alderfer |year=2006 |publisher=National Geographic Society |location=Washington, D.C. |isbn=0-7922-5314-0}}

*{{cite book |title=Shorebirds |first1=Peter |last1=Hayman |first2=John |last2=Marchant |first3=Tony |last3=Prater |year=1986 |publisher=Croom Helm |location=Breckenham, UK |isbn=0-7099-2034-2}}

*{{cite book |title=Shorebirds |first1=Peter |last1=Hayman |first2=John |last2=Marchant |first3=Tony |last3=Prater |year=1986 |publisher=Croom Helm |location=Breckenham, UK |isbn=0-7099-2034-2}}

{{Feather-tracts}}

{{Feather-tracts}}

Stripe of plumage on a bird’s head

The supercilium is a plumage feature found on the heads of some bird species. It is a stripe that runs from the base of the bird’s beak above its eye, finishing somewhere towards the rear of the bird’s head.^[1] Also known as an “eyebrow”,^[1] it is distinct from the eyestripe, which is a line that runs across the lores, and continues behind the eye.^[2] Where a stripe is present only above the lores, and does not continue behind the eye, it is called a supraloral stripe or simply supraloral.^[1] On most species that display a supercilium, it is paler than the adjacent feather tracts.^[3]

The colour, shape, or other features of the supercilium can be useful in bird identification. For example, the supercilium of the dusky warbler, an Old World warbler species, can be used to distinguish it from the very similar Radde’s warbler. The dusky warbler’s supercilium is sharply demarcated, whitish, and narrow in front of the eye, becoming broader and more buffy towards the rear, whereas that of the Radde’s warbler is diffusely defined, yellowish, and broadest in front of the eye, becoming narrower and more whitish toward the rear.^[4] The supercilium of the northern waterthrush, a New World warbler, differs subtly from that of the closely related (and similarly plumaged) Louisiana waterthrush. The Louisiana has a bicoloured supercilium, which widens significantly behind the eye, while the northern has an evenly buffy eyebrow, which is either the same width throughout or slightly narrower behind the eye.^[5]

A split supercilium’ divides above the lores. In some species, such as the jack snipe, the divided stripes reconnect again behind the eye.^[6] In others, such as the broad-billed sandpiper, the divided stripes remain separate.^[7]

A supercilium drop is a feature found on some pipits;^[8] it is a pale spot on the rear of the ear coverts, which although separated from the supercilium by an eyestripe, can appear at some angles to be a downward continuation of the supercilium.

• x
• Hayman, Peter; Marchant, John; Prater, Tony (1986). Shorebirds. Breckenham, UK: Croom Helm. ISBN 0-7099-2034-2.