Kanadawaldsänger

Bestimmung

The Canada warbler is sometimes called the "necklaced warbler", because of the band of dark streaks across its chest. The adults have minimal sexual dimorphism, although the male's "necklace" is darker and more conspicuous and also has a longer tail. Adults are 12–15 cm (4.7–5.9 in) long, have a wingspan of 17–22 cm (6.7–8.7 in), and weigh 9–13 g (0.32–0.46 oz).<p>The chest, throat, and belly of the bird are yellow, and its back is dark grey. It has no wingbars or tail spots, but the underside of the tail is white. It has a yellow line in front of its eye in the direction of the beak, but the most striking facial feature is the white eyerings or "spectacles". Immature specimens have similar coloration as adults but duller and with less pronounced facial features.<p>The songⓘ of this bird is loud and highly variable, resembling chip chewy sweet dichetty. Their calls are low chup's.<p>A 2013 study showed that male Canada warblers have two performance-encoded song types. Mode I, used mostly during the day, when unpaired either alone or near a female during early nesting, involves stereotyped songs sung slowly and regularly. Mode II, used at dawn, after pairing and when near another male, involves variable songs, sung rapidly with irregular rhythm and chirping between songs. Most of the phrases used were common to both modes, a feature unique among parulids, which ordinarily have an individual's repertoire separated into two distinct parts.[9]<p>In 2000, a female Canada warbler (or a post-hatching year-old male that failed to moult, something never before observed) in Giles County, Virginia was observed singing. Its repertoire consisted of a repeated song of 12 to 13 notes as well as several shorter songs consisting of the first five or six notes of the longer song. The bird did not respond to the playback of its own song or a recording of a male. Although female singing among the parulids has long been considered "idiosyncratic", singing by female Canada warblers is supported by the observation of female singing in congener Wilson's warbler and the closely related hooded warbler.[10]

Taxonomie

In 1760 the French zoologist Mathurin Jacques Brisson included a description of the Canada warbler in his Ornithologie based on a specimen collected in Canada. He used the French name Le gobe-mouche cendré de Canada and the Latin name Muscicapa Canadensis Cinerea. Although Brissn coined Latin names, these do not conform to the binomial system and are not recognised by the International Commission on Zoological Nomenclature. When in 1766 the Swedish naturalist Carl Linnaeus updated his Systema Naturae for the twelfth edition, he added 240 species that had been previously described by Brisson. One of these was the Canada warbler. Linnaeus included a brief description, coined the binomial name Muscicapa canadensis, and cited Brisson's work. The species is now placed in the genus Cardellina that was introduced by the French naturalist Charles Lucien Bonaparte in 1850. The species is monotypic.

Wissenschaftlicher Name

Cardellina canadensis

Autorität

(Linnaeus, 1766)

Ordnung

Passeriformes

Familie

Parulidae

Gattung

Cardellina

Verbreitung und Lebensraum

During the breeding season 82% of the population can be found in Canada and 18% in the United States. In Canada, the summer range extends from southeastern Yukon to Nova Scotia. In the United States, the range extends from northern Minnesota to northern Pennsylvania, east to Long Island, New York. It also nests in the high Appalachians as far south as Georgia. In winter, the Canada warbler's range extends from Guyana to northwestern Bolivia around the northern and western side of the Andean crest.<p>In both summer and winter seasons, the Canada warbler inhabits moist thickets. During the breeding season, the bird "nests in riparian thickets, brushy ravines, forest bogs, etc. at a wide range of elevations and across a variety of forest types. In the northwestern parts of its range, it frequents aspen forests; in the center of the range, it is found in forested wetlands and swamps; and in the south, it occupies montane rhododendron thickets."In the winter, it prefers mid- and upper-elevation habitats. In northern Minnesota, a study found that Canada warblers inhabited the shrub-forest edge, rather than mature forests or open fields with shrub. In New England, the Canada warbler was found to be "disturbance specialists" moving into patches of forests recovering from wind throw or timber removal. Because of its preference for low-height foraging in deciduous forests, it may be bounded at higher elevations as suitable habitat disappears and it suffers competition from the black-throated blue warbler which prefers similar habitats.<p>Two accidentals have been observed in Europe. The first, a moribund male was caught in Sandgerði, Iceland on September 29, 1973. The second was a first winter, probably female observed for five days in October 2006 in County Clare, Ireland.<p>The Canada warbler is one of the last birds to arrive at the breeding grounds and one of the first to leave. They may spend only two months there. They fly at night along a route generally south and west to the Texas coast, then to southern Mexico. The arrive at the winter grounds in northwestern South America in late September to early October.

Brutgebiet

NA : c Canada to se Canada and ne, e, nc USA

Überwinterungsgebiet

Panama to n SA

Zugverhalten

Vollzieher

Verhalten

Zugverhalten: Vollzieher.

Schutzstatus

Bestandstrend: rückläufig.

Bestandstrend

rückläufig