Nombre en español: Chirlobirlo

Nombre en ingles: Eastern Meadowlark

Nombre cientifíco: Sturnella magna

Familia: Icteridae

Lugar de la Foto: Serrania de Abibe

Foto: Daniel Orozco

Audio: Manuel Grosselet

El turpial oriental, carmelo, zacatero común, pradero común, cantor de pradera o chirlobirlo (Sturnella magna) es una especie de ave paseriforme de la familia Icteridae que vive en América. Se trata de un pájaro de tamaño medio y de aspecto muy similar al turpial gorjeador.

Descripción

Mide entre 21 y 22,5 cm de longitud y pesa en promedio 85 g. Los adultos tienen las partes inferiores de color amarillo con una «V» negra en el pecho y con flancos blancos con rayas negras. La parte superior es principalmente de color castaño con rayas negras. Tienen un pico puntiagudo. La cabeza presenta franjas de delante hacia atrás, alternando el negro con colores claros, como el blanco, amarillento y el castaño claro.

Ecología

Su hábitat de reproducción son los pastizales y praderas y también los campos de heno, hasta los 2500 m de altitud. Esta especie es un residente permanente a lo largo de gran parte de su área de distribución, aunque la mayoría de las aves del norte migran hacia el sur en invierno. En América Central y del Sur, que tienden a ser limitados a la zona oriental (Atlántico) lado del continente también. En 1993 esta especie fue registrada por primera vez en El Salvador y el descubrimiento de una pareja reproductora en 2004, confirmó que la especie es residente allí.

Busca alimento en el suelo o en la vegetación baja, a veces sondeando con su pico. Se alimenta principalmente de artrópodos y adicionalmente con semillas y bayas. En invierno, a menudo se alimentan en bandadas.

Anida durante los meses de verano. Construye el nido en el suelo, cubierto con un techo tejido de hierbas. Puede haber más de una hembra anidando en el territorio de un macho.

Su número aumentó en el este de Estados Unidos cuando se talaron los bosques, pero luego se disminuyó con la reducción del hábitat adecuado. En Centroamérica se ha expandido en la cuenca del Pacífico.

Huevos de Sturnella magna

Taxonomía

La especie fue descrita inicialmente por Linneo en 1758 en Systema naturae, como Alauda magna, sin diferenciarla del turpial occidental (Sturnella neglecta) y confundiéndolas con dos especies de África: el bisbita del Cabo y el bisbita gorgigualdo. Posteriormente Linnaeus detectó el error y diferenció la especie.

El canto melancólico con silbidos sencillos de S. magna, lo diferencia de S. neglecta, cuyo canto es aflautado y complejo.

La subespecie S. m. lilianae, del norte de México, es a veces tratada como una especie diferente Sturnella lilianae.

Eastern meadowlark

The eastern meadowlark (Sturnella magna) is a medium-sized icterid bird, very similar in appearance to the western meadowlark. It occurs from eastern North America to South America, where it is also most widespread in the east.

Description

The adult eastern meadowlark measures from 19 to 28 cm (7.5 to 11.0 in) in length and spans 35–40 cm (14–16 in) across the wings. Body mass ranges from 76 to 150 g (2.7 to 5.3 oz).^[3]^[4] The extended wing bone measures 8.9–12.9 cm (3.5–5.1 in), the tail measures 5.3–8.6 cm (2.1–3.4 in), the culmen measures 2.8–3.7 cm (1.1–1.5 in) and the tarsus measures 3.6–4.7 cm (1.4–1.9 in). Females are smaller in all physical dimensions. Adults have yellow underparts with a black «V» on the breast and white flanks with black streaks. The upperparts are mainly brown with black streaks. They have a long pointed bill; the head is striped with light brown and black.

The song of this bird is of pure, melancholy whistles, and thus simpler than the jumbled and flutey song of the western meadowlark; their ranges overlap across central North America. In the field, the song is often the easiest way to tell the two species apart, though plumage differences do exist, like tail pattern and malarcoloration.

The pale Lilian’s meadowlark of northern Mexico and the southwestern US is sometimes split off as a separate species.

Taxonomy

The Cuban subspecies S. m. hippocrepis (Wagler, 1832) is small and more streaked below, and may be a separate species

This species was first described by Linnaeus in his 1758 Systema naturae as Alauda magna. The type locality is mistakenly given as «America, Africa».

Linnaeus’ error is explained by two facts: first, he did not distinguish between the eastern and western meadowlarks. The peculiar belief that this bird also occurred in Africa is due to confusion of the yellow-breasted meadowlarks with certain longclaws (Macronyx), quite unrelated African songbirds. Specifically the Cape longclaw (M. capensis) and the yellow-throated longclaw (M. croceus) share similar habitat and habits, explaining the long hind toe; their plumage pattern however is all but identical, a striking example of convergent evolution. As this exact pattern provides no obvious adaptive benefit compared to that of other meadowlarks and longclaws, it seems to have arisen twice by sheer chance.

Linnaeus recognized his error less than a decade later, separating the longclaws from their meadowlark look-alikes.

The scientific name Sturnella magna is Latin for, rather confusingly, «large little starling», the generic name having been given due to the meadowlarks’ behavior being similar to starlings.

Ecology

Their breeding habitat is grasslands and prairie, also pastures and hay fields. This species is a permanent resident throughout much of its range, though most northern birds migrate southwards in winter. In 1993 this species was first recorded in El Salvador, and the discovery of a breeding pair in 2004 confirmed that the species is a resident there.

These birds forage on the ground or in low vegetation, sometimes probing with the bill. They mainly eat arthropods, but also seeds and berries. In winter, they often feed in flocks.

Nesting occurs throughout the summer months. The nest is also on the ground, covered with a roof woven from grasses. There may be more than one nesting female in a male’s territory.

The numbers of this species increased as forests were cleared in eastern North America. This species is ideally suited to farmland areas, especially where tall grasses are allowed to grow. Their numbers are now shrinking with a decline in suitable habitat. On the other hand, its range is expanding in parts of Central America toward the Pacific (western) side of the continent, in agricultural-type areas.

Conservation efforts

Eastern meadowlarks are species at risk in Nova Scotia and the subject of agricultural conservation program seeking to reduce mortality through modified practices.Allowing marginal areas of fields on farms to seed with grass can provide nesting habitat for meadowlarks and all grassland birds. Delaying hay harvest can also improve survival, giving young meadowlarks a chance of fledging