Mourning Warbler

Identificazione

Robusta silvide che si trova vicino al suolo in fitta vegetazione. Gialla inferiormente con testa grigio-blu e dorso oliva. I maschi adulti mostrano una macchia nera sul petto. Le femmine hanno la testa di un grigio più pallido; gli immaturi sono più olivastri con una gola giallastra. Nidifica in radure cespugliose e erbose all'interno di foreste miste o di conifere. Spesso predilige i roveti di lampone. Tende a rimanere nascosta nella vegetazione bassa, quindi può essere difficile da vedere. Ascoltare il suo canto rullante, "churry churry churry chew". Molto simile alla Silvide di MacGillivray (MacGillivray’s Warbler), ma con poca sovrapposizione di areale, e la Silvide piangente (Mourning Warbler) ha la coda leggermente più corta e manca di evidenti archi oculari bianchi. Spesso confusa anche con la Parula comune (Common Yellowthroat), specialmente in autunno, ma la Silvide piangente è più grande, con un becco rosato più robusto e parti inferiori di un giallo più brillante.

Tassonomia

Nome scientifico

Geothlypis philadelphia

Autorità

(Wilson, A, 1810)

Ordine

Passeriformi

Famiglia

Parulidae

Genere

Geothlypis

Areale e habitat

Mourning warblers have breeding ground in southern Canada, and are commonly seen during migration in the central and eastern United States, Belieze, Bonaire, Puerto Rico, Guatemala, Panama, and other Central American Islands. These birds migrate to Central America and northern South America. Mourning warblers are low or ground nesters, and prefer disturbed forests with a thick under-story and covered canopy. In the winter they prefer wet lowland habitat with dense vegetation.

Areale riproduttivo

NA : c Canada to se Canada and ne USA

Areale non riproduttivo

Nicaragua to n SA

Migrazione

Complete migrants

Comportamento

Mourning warblers forage low in vegetation, sometimes catching insects in flight. These birds mainly eat insects, also some plant material including fruiting bodies from the Cecropia tree in winter. Their diet is not well documented but also includes insect larvae and spiders that they pick from the branches of shrubs. They are also known to remove the legs and wings of the insects before consuming.<p>Mourning warblers breed in southern Canada. Their breeding habitat is thickets and semi-open areas with dense shrubs across Canada east of the Rockies and the northeastern United States. The nest is an open cup placed on the ground in a well-concealed location under thick shrubs or other vegetation. Their nest is usually made out of grass, leaves and bark and lined with roots or other thin material.<p>Mourning warblers typically lay 2-5 eggs, which are white or speckled brown and black in appearance. Incubation is 12 days long and both adult males and females utilize a distraction technique of pretending to have broken wings to distract predators from their nest. Mourning warblers have young with gray tufts on their head and red mouths. Adult females are also known consume their eggs after their young hatch. The number of days for young to fledge is 7–9.<p>The song of this bird is a bright repetitive warble. The warble consists of rolling phrases that sound that typically lower in volume at the end and can sound like "chirry, chirry, chirry, chorry, chorry." The call is a sharp chip. There are usually two different pitched calls, with one higher than the harsh chip.

Conservazione

According to the North American Breeding Bird Survey, Mourning Warbler populations have declined by about 43% in the last 50 years. However, they are still categorized as a species of least concern with 17 million estimated as a global breeding population by Partners in Flight. As they have a preference for disturbed forests, they may be benefitting from human development that may be negatively effecting the habitats of other bird species.

Tendenza della popolazione

declining