Walddrossel

Bestimmung

The adult wood thrush is 18 to 21.5 cm (7.1 to 8.5 in) long, with a wingspan of 30 to 40 cm (12 to 16 in) and a body mass of 48 to 72 g (1.7 to 2.5 oz). Among standard measurements, the wing chord is 9.6 to 11.6 cm (3.8 to 4.6 in), the bill is 1.6 to 2 cm (0.63 to 0.79 in) and the tarsus is 2.8 to 3.3 cm (1.1 to 1.3 in). It is distinctly larger than the Catharus thrushes with which the species is often sympatric but slightly smaller than the common American robin. The longest known lifespan for a wood thrush in the wild is 8 years, 11 months. The crown, nape, and upper back are cinnamon-brown, while the back wings, and tail are a slightly duller brown. The breast and belly are white with large dark brown spots on the breast, sides, and flanks. It has white eye rings and pink legs. Other brownish thrushes have finer spotting on the breast. The juvenile looks similar to adults, but has additional spots on the back, neck, and wing coverts. The male and female are similar in size and plumage.<p>The wood thrush has been reported to have one of the most beautiful songs of North American birds. American naturalist Henry David Thoreau wrote:<p>Whenever a man hears it he is young, and Nature is in her spring; wherever he hears it, it is a new world and a free country, and the gates of Heaven are not shut against him.<p>While the female is not known to sing, the male has a unique song that has three parts. The first subsong component is often inaudible unless the listener is close, and consists of two to six short, low-pitched notes such as bup, bup, bup. The middle part is a loud phrase often written ee-oh-lay, and the third part is a ventriloquial, trill-like phrase of non-harmonic pairs of notes given rapidly and simultaneously.<p>The male is able to sing two notes at once, which gives its song an ethereal, flute-like quality. Each individual bird has its own repertoire based on combinations of variations of the three parts. Songs are often repeated in order. The bup, bup, bup phrase is also sometimes used as a call, which is louder and at a greater frequency when the bird is agitated. The wood thrush also use a tut, tut to signal agitation. The nocturnal flight call is an emphatic buzzing heeh.

Taxonomie

The wood thrush was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae. He placed it with the thrushes in the genus Turdus and coined the binomial name Turdus mustelinus. Gmelin based his account on the "Tawny thrush" that had been described in 1785 by the Welsh naturalist Thomas Pennant in his book Arctic Zoology. Pennant specified the locality as the province of New York. The wood thrush is now the only species placed in the genus Hylocichla that was introduced in 1864 by the American naturalist Spencer Baird. The species is monotypic: no subspecies are recognised. The generic name is a translation of its common name, derived from the Greek words hyle/ύλη "woodland" and cichle/κιχλη "thrush" or "fieldfare". The specific name comes from the Latin mustela "weasel".<p>This thrush is closely related to the other typical American thrushes of the genus Catharus, and is sometimes merged into that genus. It has been considered close to the long-distance migrant species of that genus, as opposed to the generally resident nightingale-thrushes, but this appears to be erroneous. The wood thrush also appears to be fairly closely related to the large Turdus thrushes, such as the American robin."Wood thrush" is the official name given to this species by the International Ornithologists' Union (IOC).

Wissenschaftlicher Name

Hylocichla mustelina

Autorität

(Gmelin, JF, 1789)

Ordnung

Passeriformes

Familie

Turdidae

Gattung

Hylocichla

Verbreitung und Lebensraum

The wood thrush's breeding range extends from Manitoba, Ontario and Nova Scotia in southern Canada to northern Florida and from the Atlantic coast to the Missouri River and the eastern Great Plains. It migrates to southern Mexico through to Panama in Central America in the winter, mostly in the lowlands along the Atlantic and Pacific coasts. It generally arrives on the U.S. Gulf Coast during the first week of April. Fall migration usually begins in mid-August and continues through mid-September. Migration takes place at night, allowing them to find their direction from the stars and orient themselves by detecting the Earth's magnetic field.<p>The wood thrush prefers deciduous and mixed forests for breeding. It prefers late-successional, upland mesic forests with a moderately-dense shrub layer. It favors areas with running water, moist ground, and high understorey cover. The breeding habitat generally includes trees taller than 16 m (52 ft), a fairly open forest floor, moist soil, and leaf litter, with substrate moisture more important than either canopy cover or access to running water. The wood thrush can breed in habitat patches as small as 0.4 hectares (0.99 acres), but it runs the risk of higher predation and nest parasitism. The wood thrush's breeding range has expanded northward, displacing the veery and hermit thrush in some locations. In recent times, as a result of fragmentation of forests, it has been increasingly exposed tonest parasitism by brown-headed cowbirds, as well as loss of habitat in the winter range.<p>The wood thrush has become a symbol of the decline of Neotropical songbirds of eastern North America, having declined by approximately 50% since 1966. Along with many other species, this thrush faces threats both to its North American breeding grounds and Central American wintering grounds. Forest fragmentation in North American forests has resulted in both increased nest predation and increased cowbird parasitism, significantly reducing their reproductive success. A study by the Cornell Laboratory of Ornithology was the first large-scale analysis that linked acid rain to this thrush's decline. Continued destruction of primary forest in Central America eliminated preferred wood thrush wintering habitats, likely forcing the birds to choose secondary habitats where mortality rates are higher. In spite of this, the wood thrush is considered to be Least Concern.<p>The wood thrush has been recorded twice as a vagrant in Europe, in Iceland at Kvísker in Öræfi East Skaftafellssýsla by Björnsson Hálfdán on 23 October 1967 and on Wingletang Down, St Agnes, Isles of Scilly, England on 7 October 1987.

Brutgebiet

NA : c, e USA and se Canada

Überwinterungsgebiet

Mittelamerika

Zugverhalten

Vollzieher

Verhalten

Zugverhalten: Vollzieher.

Schutzstatus

Bestandstrend: rückläufig.

Bestandstrend

rückläufig