Weißkehlammer

Bestimmung

The white-throated sparrow is a passerine bird of the New World sparrow family Passerellidae. It measures 15 to 19 cm (5.9 to 7.5 in) in length with a wingspan of 23 cm (9.1 in). Typical weight is 22 to 32 g (0.78 to 1.13 oz), with an average of 26 g (0.92 oz). Among standard measurements, the wing chord is 6.3 to 7.9 cm (2.5 to 3.1 in), the tail is 6.8 to 7.7 cm (2.7 to 3.0 in), the bill is 1 to 1.2 cm (0.39 to 0.47 in) and the tarsus is 2.2 to 2.4 cm (0.87 to 0.94 in). They are similar in appearance to the white-crowned sparrow, but with white throat markings and yellow lores.<p>There are two adult plumage variations known as the tan-striped and white-striped forms. On the white-striped form the crown is black with a white central stripe. The supercilium is white as well. The auriculars are gray with the upper edge forming a black eye line.<p>On the tan form, the crown is dark brown with a tan central stripe. The supercilium is tan as well. The auriculars are gray/light brown with the upper edge forming a brown eye line. Both variations feature dark eyes, a white throat, yellow lores and gray bill. There is variation and some individuals may show dark lateral stripes of each side of the throat.<p>They almost always pair with the opposite color morph for breeding. The two color morphs occur in approximately equal numbers. Both male and female white-striped birds are more aggressive than tan-striped birds during the breeding season. The aggression is linked to an increased rate of estrogen receptor alpha expression in white-striped birds.<p>The breast has gray/tan streaks and the streaks continue down the flanks but the belly is generally light gray. The wings are rufous with two distinct white wing bars. Sexes are morphologically similar.

Taxonomie

In 1760 the English naturalist George Edwards included an illustration and a description of the white-throated sparrow in the second volume of his Gleanings of Natural History. He used the current English name. Edwards based his hand-coloured etching on a "neat drawing in colours" supplied by the American naturalist William Bartram from Philadelphia in Pennsylvania. When the German naturalist Johann Friedrich Gmelin revised and expanded Carl Linnaeus's Systema Naturae in 1789 he included the white-throated sparrow. He placed it with the finches in the genus Fringilla and coined the binomial name Fringilla albicollis. The white-throated sparrow is now one of five American sparrows placed in the genus Zonotrichia that was introduced by William Swainson in 1832. The genus name is from Ancient Greek ζωνη (zōnē) meaning "band" and θριξ (thrix), τριχος (trikhos) meaning "hair". The specific epithet albicollis combines Latin albus meaning "white" with Modern Latin -collis meaning "necked". The species is monotypic: no subspecies are recognised.

Wissenschaftlicher Name

Zonotrichia albicollis

Autorität

(Gmelin, JF, 1789)

Ordnung

Passeriformes

Familie

Passerellidae

Gattung

Zonotrichia

Verbreitung und Lebensraum

Breeding range: NA : nw, w Canada and ne, nc USA. Non-breeding range: to n Mexico.

Brutgebiet

NA : nw, w Canada and ne, nc USA

Überwinterungsgebiet

bis nach Nordmexiko

Zugverhalten

Vollzieher

Verhalten

Zugverhalten: Vollzieher.

Schutzstatus

Bestandstrend: rückläufig.

Bestandstrend

rückläufig