Nombre en español: Reinita de Pensilvania

Nombre en inglés: Chestnut-sided Warbler

Nombre científico: Setophaga pensylvanica

Familia: Parulidae

El reinita de Pensilvania (Setophaga pensylvanica),​ también denominada reinita flanquicastaña o de costillas castañas, bijirita de costados castaños, chipe flanquicastaño, chipe pardo blanco, cigüita de costados castaños,​ es una especie de ave paseriforme perteneciente a la familia Parulidae. Es una especie migratoria que se reproduce en Canadá y Estados Unidos y pasa el invierno en América Central y Colombia.

Características

Los machos adultos en primavera y verano son inconfundibles: la cara es blanca con rayas oculares negras que se extienden hacia el cuello y la nuca en un patrón característico. La espalda, alas y cola son amarillento verdosas, y listadas, y en el ala hay dos barras blancas muy evidentes. Otra señal inconfundible son los costados del pecho color castaño. Garganta, pecho y vientre son blancos.

El plumaje reproductivo de la hembra es similar al del macho, pero ligeramente más deslavado. Tiene menos castaño en los costados y el patrón facial no se dibuja completamente.

En época de migración e hibernación, se pierden las características distintivas en los adultos, aunque conservan algo de castaño en los costados y negro en la cara. En este época, el plumaje es verdoso sin listas en las partes superiores y gris y blanco por abajo; la cola y las alas son más oscuras, con dos barras amarillas en el ala. La ausencia de rayas en los costados sirve para distinguirlo del chipe gorrinegro (Dendroica striata) en la época de hibernación.

El plumaje de los inmaduros es similar al de los adultos en otoño e invierno, con la diferencia que no hay negro en la cara ni castaño en los flancos.

Distribución

Se reproduce en el sur de Canadá y el este de los Estados Unidos. En otoño migra al sur, para establecerse desde el sureste de México hasta el norte de Colombia.

En México es un ave de paso por la vertiente del Golfo y la península de Yucatán —aunque hay registros accidentales en otras partes del país— y de invernada en el sur de Veracruz, sur de Tabasco y Chiapas.

Es transitoria en las Antillas y accidental en El Salvador, Venezuela y la isla de Trinidad.

Hábitat

Vive en áreas húmedas o semihúmedas, en bosques perennifolios, límites de bosques, matorrales y campos de cultivo. Puede llegar hasta los 1500 m snm. Se alimenta básicamente de insectos, pero también consume bayas.

Chestnut-sided warbler

The chestnut-sided warbler (Setophaga pensylvanica) is a New World warbler. They breed in eastern North America and in southern Canada westwards to the Canadian Prairies. They also breed in the Great Lakes region and in the eastern United States.

Etymology

The genus name Setophaga is from Ancient Greek ses, «moth», and phagos, «eating», and the specific pennsylvanicus means «Pennsylvania».

Migration range

These birds are migratory, wintering in Central America south to northern Colombia,^[3] with an unconfirmed sighting from as far south as Ecuador; they are also very rare vagrants to western Europe. They arrive in their breeding range in May and depart by mid-September.

Description

This species is a moderately-sized New World warbler. Despite having very different plumage, it is thought to be closely related to the widespread yellow warbler. In total, this species measures from 10 to 14 cm (3.9 to 5.5 in) in length and spans 16 to 21 cm (6.3 to 8.3 in) across the wings. Body weight ranges from 8 to 13.1 g (0.28 to 0.46 oz). Among standard measurements, the wing chord is 5.7 to 6.8 cm (2.2 to 2.7 in), the tail is 4.2 to 5.8 cm (1.7 to 2.3 in), the bill is 0.9 to 1 cm (0.35 to 0.39 in) and the tarsus is 1.7 to 1.9 cm (0.67 to 0.75 in).

In the summer, male chestnut-sided warblers are unmistakable in appearance. They display dark-streaked gray backs, white faces, black eyestripes and greenish crowns. Their underparts are white, with chestnut flanks, and they also have two white wing bars. The adult females resemble washed-out versions of the summer male, and in particular, the females lack the strong head pattern, and also have little to no chestnut coloring on their flanks.

Non-breeding birds of both sexes have greenish heads, and greenish upperparts which are usually unstreaked. They also have unstreaked pale grey breasts. Their wing bars are always present in their plumages. Their lack of streaking and greenish backs helps to distinguish this species from the larger blackpoll warbler in the fall.

Sound

The songs are high whistled lines often described as pleased, pleased, pleased to MEECHA. This accented song is used primarily to attract a female and decrease in frequency once nesting is well under way. Males also sing unaccented songs (without the MEECHA at the end) and these are used mostly in territory defense and aggressive encounters with other males. Some males sing only unaccented songs, and they are less successful at securing mates than males that sing both songs. Their calls are harsh chips. Despite the fact that songs for courtship do not vary across small distances, songs for aggression are highly localized, a possible explanation being that female Chestnut-Sided Warblers disperse over long distances.

Breeding and habitat

The chestnut-sided warbler has benefited from the clearing of mature forests. They make use of the abundant second growth habitats. In the tropics where they winter however, the species occurs mostly in mature tropical rainforests. Their cup-shaped nests are placed in a low bush, which is usually located in young deciduous woodland or scrub. These birds lay 3–5 eggs that are creamy white or greenish with brown speckles in color. The nest is a small cup woven of bark strips, weed stems, grasses, and plant down. The nest is usually placed in a small crotch of a shrub or vertical tangle of vines no more than 2 m (6.6 ft) above the ground. This species is frequently parasitized by brown-headed cowbirds.

Population

This bird’s numbers have increased as second growth forest became more common in the east in the late 19th century; their numbers have declined slightly since then.

Food

Chestnut-sided warblers are primarily insectivorous. They forage actively in shrubs and small trees, and sometimes will attempt to catch insects in mid-air. Most foraging consists of gleaning insects from foliage. They will include berries in their winter diets, such as those of Cymbopetalum mayanum; such trees can be used to attract wintering birds into gardens and parks.

Fuentes: Wikipedia/eBird/xeno-canto